DD Platform Bearing Failure Guide - Freightliner...

DDC-SVC-MAN-0196

DD Platform Bearing Failure Guide

Specifications are subject to change without notice. Detroit Diesel Corporation is registered to ISO 9001:2001.Copyright Detroit Diesel Corporation. All rights reserved. Detroit Diesel Corporation is a Daimler company.Printed in U.S.A.

Table of Contents

1 DD Platform Bearing Failure Guide...................................................................................................................................... 32 A Note on Warranty................................................................................................................................................................ 43 Design of the Engine Lubrication System............................................................................................................................. 54 Driver Questionnaire............................................................................................................................................................. 125 Vehicle and Engine Inspection............................................................................................................................................. 136 Gathering and Interpreting Electronic Information.......................................................................................................... 147 Oil Filter and Oil Filter Standpipe Inspection.................................................................................................................... 168 Checking for Contaminated Lubricating Oil...................................................................................................................... 229 Debris in the Oil Pan............................................................................................................................................................. 2310 Oil Pump and Oil Suction Manifold Inspection............................................................................................................... 2511 Sputtered Bearing Description and Operation................................................................................................................. 2812 Lower End Bearing Inspection........................................................................................................................................... 3013 Types of Lower End Bearing Failures............................................................................................................................... 3314 Vertical Failure vs. Horizontal Failure............................................................................................................................. 4515 Probability of a Defect......................................................................................................................................................... 4716 Failure Scenarios................................................................................................................................................................. 4817 Conclusion............................................................................................................................................................................ 5018 Glossary of Terms................................................................................................................................................................ 5119 Technician Checklist........................................................................................................................................................... 53

Table of Contents

2 All information subject to change without notice.Copyright 2016 DETROIT DIESEL CORPORATIONDDC-SVC-MAN-0196

1 DD Platform Bearing Failure Guide

The purpose of this failure guide is to help Repair Outlets identify the root cause of a lower-end bearing failure on a DDPlatform engine. This is an educational resource guide to enhance knowledge of these failures. This is not step-by-steptroubleshooting.

The vehicle may enter the shop with any of the following complaints: Rod out of the Block Engine Locked Up or Seized No Crank / No Start Noisy or Knocking

Determining the root cause or Primary Failed Part (PFP) is necessary before deciding responsibility for the failure andmaking a proper repair. It is important to know that accurate failure analysis can be a time consuming exercise and is more ofan investigation than a diagnosis.

This information applies to all DD13, DD15 and DD16 On-Highway engines.

The guide is separated into 18 sections.

1. A Note on Warranty Refer to section "A Note on Warranty"2. Design of the Engine Lubrication System Refer to section "Design of the Engine Lubrication System"3. Driver Questionnaire Refer to section "Driver Questionnaire"4. Vehicle and Engine Inspection Refer to section "Vehicle and Engine Inspection"5. Gathering and Interpreting Electronic Information Refer to section "Gathering and Interpreting Electronic Information"6. Oil Filter and Oil Filter Standpipe Inspection Refer to section "Oil Filter and Oil Filter Standpipe Inspection"7. Checking for Contaminated Lubricating Oil Refer to section "Checking for Contaminated Lubricating Oil"8. Debris in the Oil Pan Refer to section "Debris in the Oil Pan"9. Oil Pump and Oil Suction Manifold Inspection Refer to section "Oil Pump and Oil Suction Manifold Inspection"

10. Sputtered Bearing Description and Operation Refer to section "Sputtered Bearing Description and Operation"11. Lower End Bearing Inspection Refer to section "Lower End Bearing Inspection"12. Types of Lower End Bearing Failures Refer to section "Types of Lower End Bearing Failures"13. Vertical Failure vs. Horizontal Failure Refer to section "Vertical Failure vs. Horizontal Failure"14. Probability of a Defect Refer to section "Probability of a Defect"15. Failure Scenarios Refer to section "Failure Scenarios"16. Conclusion Refer to section "Conclusion"17. Glossary of Terms Refer to section "Glossary of Terms"18. Technician Checklist Refer to section "Technician Checklist"


All information subject to change without notice. 3DDC-SVC-MAN-0196Copyright 2016 DETROIT DIESEL CORPORATION

2 A Note on Warranty

Detroit Warranty covers engine repairs to correct any malfunction occurring during the warranty period resulting fromdefects in material or manufacturer workmanship of a Detroit product. Determining the root cause of failure or PrimaryFailed Part (PFP) is essential in determining the warranty eligibility. There are several factors that should be considered whendetermining the PFP and its failure mode. These factors include:

Workmanship

Refer to the service policy manual for how to proceed in repairs with a failure that is a result of improper workmanship bya service outlet.

Contaminated fluids. Examples include, but are not limited to: Contamination as a result of the incorrect fluid being added to the unit. This can include, but is not limited to:

- Diesel Exhaust Fluid (DEF) in the fuel or fuel in the DEF.- Fuel, lubricating oil, or coolant being used outside of the specifications listed in the EPA07/EPA10/GHG14 DD

Platform Operators Manual or GHG17 DD Platform Operators Manual.

Operator-induced failures, abuse, negligence or certain modifications. Examples include, but are not limited to: Operator-induced engine overspeed. Misapplication, misuse, or storage damage. Failing to follow the correct maintenance schedule. Failure due to a modification exceeding Detroit specifications.

Accidents or acts of nature. Examples include, but are not limited to:

Flood damage. Hurricane damage. Lightning damage. Vehicular accidents.

The examples above are some examples of situations that would exclude the failure from warranty eligibility.

If the failure is identified to be eligible for warranty, the unit should be restored to operating condition by repairing orreplacing only the defective or damaged parts that are necessary, according to the terms of the appropriate warrantystatement. Other parts removed in the repair process will be reinstalled as is, unless the user authorizes the additionalexpense. The intent of a warranty repair is to repair or replace the warranted parts and restore the rest of the engine to itsoperating condition prior to the warrantable failure, not to restore the engine to like-new condition.

2 A Note on Warranty


3 Design of the Engine Lubrication System

It is important to understand the design of the engine and the flow of lubricating oil within the engine and various lubricatedcomponents when trying to determine the root cause of a lower-end bearing failure.

The following schematics and illustrations show the oil flow to the various engine components.

1. Engine Brake Actuators2. Turbocharger3. Crankcase Breather4. Oil Pump5. Oil Pressure Regulator Valve6. Anti Drainback Valve7. Oil Suction Manifold Assembly8. Piston Cooling Nozzles

9. Oil Cooler10. Oil Filter11. Oil Filler Neck12. Intake Rocker Arm Oil Supply13. Engine Brake Actuator Oil Supply14. Exhaust Rocker Arm Oil Supply15. Gear Train Oil Supply16. Main Bearing Oil Supply

Figure 1. DD13, DD15 AT and GHG17 DD15 Oil Flow Schematic



1. Engine Brake Actuators2. Turbocharger3. Axial Power Turbine (APT)4. Crankcase Breather5. Oil Pump6. Oil Pressure Regulator Valve7. Anti Drainback Valve8. Oil Suction Manifold9. Piston Cooling Nozzles

10. Oil Cooler11. Oil Filter12. Oil Filler Neck13. Intake Rocker Arm Oil Supply14. Engine Brake Actuator Oil Supply15. Exhaust Rocker Arm Oil Supply16. Gear Train Oil Supply17. Main Bearing Oil Supply

Figure 2. DD15 TC and DD16 Oil Flow Schematic



1. Oil Pressure Sensor Location2. Oil Temperature Sensor Location3. Oil Return Drains from Overhead4. Main Oil Gallery

5. Oil Supply from Oil Pump6. Clean Oil to Main Oil Gallery7. Crankcase Oil Fill and Oil Filter Drain Passage

Figure 3. Left Side of Cylinder Block



1. Crankcase Breather Passage2. Oil Return Drains from Overhead3. Turbocharger Oil Supply

4. Turbocharger Oil Drain5. Crankcase Breather Drain6. Crankcase Breather Oil Supply

Figure 4. Right Side of Cylinder Block TC Engine (AT Similar)



1. Main Bearing and Crankshaft Bore2. Main Oil Gallery (Side A) and Secondary Oil Gallery

(Side B)3. Cooling Jacket

4. Bay to Bay Breather Passage5. Crankshaft Main Bearing Cap

Figure 5. Cylinder Block Cutaway (from the rear)



1. Oil PassageFigure 6. Rear of Cylinder Block TC Engine (AT Similar)



1. Oil Supply to Overhead2. Oil Supply to Idler No. 5

3. Cooling Passages4. Oil Return Drains from Overhead

Figure 7. Top of Cylinder Block (fire deck)



4 Driver Questionnaire

The following is a driver questionnaire to obtain information about the failure event. Detroit understands the driver may notalways be available or may not know the answers to all of these questions. This is simply an attempt to gather moreinformation that could help with determining the root cause of the failure.

1. Where did the failure occur? (physical location)____________________________________________________________________________________________________________________________________________________________________________________________

2. Were there any abnormal issues prior to the failure? Please describe.____________________________________________________________________________________________________________________________________________________________________________________________

3. When and where was the last oil and filter change performed?____________________________________________________________________________________________________________________________________________________________________________________________

4. Were there any recent repairs? Please describe.____________________________________________________________________________________________________________________________________________________________________________________________

5. Has the truck been in any recent accidents or sustained any damage? Please describe.____________________________________________________________________________________________________________________________________________________________________________________________

6. Any other helpful information?____________________________________________________________________________________________________________________________________________________________________________________________

4 Driver Questionnaire


5 Vehicle and Engine Inspection

A brief walk around is important to identify any accidents or damage to the vehicle that may have led to a lack of adequatelubrication. It is also important to identify any current issues or recent engine repairs that may be related to a gross oil leak,contaminated lube oil or introduction of debris into the lubrication system.

Inspect the truck as follows:1. Inspect for new components such as the bumper, hood, side fairings, front suspension, wheels or exhaust.2. Check for any recent paint work.3. Inspect for frame damage.4. Record observations.

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Inspect the engine and under hood as follows:

1. Check for new components such as the cooling package, oil pan, engine mounts (front and rear), oil coolant moduleincluding water pump and thermostat, camshaft housing, turbocharger, turbocompound system (if equipped) oraftertreatment system.

2. Inspect for any gross external oil leaks.3. Check for any unusually clean areas on the engine, indicating possible recent repairs.4. Inspect for any aftermarket equipment such as oil filtration systems or performance enhancing devices.5. Check the oil level. If overfull, there may be coolant or fuel contamination.6. Record observations.

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________



6 Gathering and Interpreting Electronic Information

There are many sources of electronic information that can be useful tools during an engine failure investigation. Theseinclude DDEC Reports, DiagnosticLink , Virtual Technician and the Detroit Warranty System.

DDEC Reports

Obtain DDEC Reports and check for a maximum engine speed above 2500 rpm. The Life to Date and Monthly ActivityReports should be reviewed. Engine failures relating to an engine overspeed can range from lower end bearing failure tomultiple connecting rods exiting the cylinder block. Location of the failure (region and terrain) should be reviewed todetermine if the overspeed was driver induced. If there is an engine overspeed fault in DiagnosticLink, review the road speedat the time of the fault code. If the truck was driving down the road when the engine overspeed occurred, this is considered adriver induced overspeed. An engine overspeed event due to fuel or oil occurs while the vehicle is stationary.

DiagnosticLink Log File

Obtain a Key-On-Engine-Off (KOEO) log file using DiagnosticLink, if the Motor Control Module (MCM) is intact. Reviewand record fault codes.

Codes of interest for a lower end bearing failure:

Oil pressure codes- Many possibilities: low oil level, damage to the oil supply system, contaminated lube, sensor, wiring, etc.

Oil temperature codes- Possible contaminated lube, engine overheat condition or improper maintenance.

Coolant level codes- Possible contaminated lube from a head gasket or liner failure; gross coolant leak.

Coolant temperature codes- Engine overheat condition

Rail pressure codes- Possible injector failure causing a backwards running engine or oil dilution

Backwards running engine codes- Reverse engine rotation due to injector failure. Reversing the oil pump results in no oil to the lower end bearings. Check

for excessive soot in the air intake system, indicating the engine ran backwards. Test E in "Symptom Diagnostics - HardStart/No Start" can be a helpful reference.

Water in Fuel (WIF) codes- Possible injector failure and overspeed or backwards running engine caused by contaminated fuel. Check for signs of

DEF in the fuel filter module. Refer to "Diesel Exhaust Fluid in the Fuel" diagnostics for further information.

It should be noted that a fault code may not be directly associated with the failure event. The time stamp and number ofoccurrences must be evaluated with relation to the time of the failure. A high occurrence counter for a code resulting in anengine shutdown (Low Oil Pressure, Low Coolant Level, or High Coolant Temperature) could indicate the driver was usingthe engine shutdown override to continue operating the vehicle. The purpose of the engine shutdown override is to allowmovement of the vehicle to a safe location where it can be inspected by a qualified repair technician or towed to a differentlocation. The override is not meant to continue operation of the vehicle with possible engine damaging conditions.

Virtual Technician

If the vehicle is equipped with Virtual Technician (VT), the VT Dashboard can be a valuable tool for accessing historicalfault code data. Certain engine damaging codes can store log files that may help with determining the cause of the failure. VTcan also provide the geographical location of the failure, if fault codes were logged. The VT Dashboard can be found inAccess Freightliner.

Detroit Warranty System

Reviewing the Detroit warranty repair history for an engine is an essential step in the failure analysis process.

See the sample Warranty claim history below. There are several repairs listed that should be reviewed.

6 Gathering and Interpreting Electronic Information


Figure 8. Sample Detroit Warranty History Injector replacement at 170,390 miles

- Possible overfueling, oil dilution, overspeed or backwards running engine. Cam Housing at 230,513 miles

- Possible debris introduced to engine lubrication system during repair in the form of dirt or abrasive material.- Possible aluminum debris from a thread repair.

Oil Pan Seal at 235,565 miles- Possible debris left in the oil pan during repair.

Turbocharger at 299,028 miles- Possible turbo bearing debris in the oil pan.- Possible gross loss of oil resulting in lack of lubrication.

The above claim examples indicate a need to look further into those claims and repairs to ensure they have not led to thelower end bearing failure. There are visual signs to indicate improper repairs were made. These will be discussed in moredetail throughout this guide.



7 Oil Filter and Oil Filter Standpipe Inspection

Proper oil filtration and a clean engine lubrication system is an absolute requirement. DD engines use sputtered main and rodbearings. These bearings are superior in load carrying capacity when compared to standard tri-metal bearings. However,sputtered bearings are less forgiving to debris and lack of lubrication conditions.

Oil Filter Identification

The current oil filter used in DD engines is a stack design with no glue beads. It uses shorter pleats in conjunction with twoadditional discs in the middle of the filter. This design was released in early 2013 and has the highest quality of filtration. Theoriginal early design used six glue bead rings on the outside diameter of the oil filter. The Detroit-branded filter is therecommended oil filter for a DD engine.

The oil filter used in the MBE 4000 engine is similar in size and fitment to the DD platform oil filter. However, an MBE4000 oil filter must not be used in a DD engine. Damage to the oil filter bypass valve can occur if an incorrect oil filter isused. In addition, the MBE 4000 filter is not designed to handle the oil volume and pressures of a DD engine. The figurebelow shows the difference between the current DD oil filter and an MBE 4000 oil filter.

Figure 9. Current DD Oil Filter (left-new) and MBE 4000 Oil Filter (right-used)Oil Filter Inspection



Inspect the oil filter for signs of debris. If the engine ran for any amount of time with damaged lower end bearings, there maybe bearing material in the pleats of the oil filter and in the oil filter housing. Look for other foreign material such asaluminum shavings, plastic or dirt. If foreign debris is found, investigate further to find the source of the debris.

Coolant contamination of the oil filter will typically result in distorted oil filter pleats or sludge build-up, depending on howlong the engine ran with coolant in the oil. See the figures below. The oil filter may be noticeably heavier due to thesaturation of coolant. Coolant contamination of the lube system can be detrimental to the lower end bearings, as coolant doesnot provide the necessary lubricity. The source of the coolant contamination must be determined. Contaminated lubricatingoil will be discussed later in this manual.

Figure 10. Oil Filter Contaminated with Coolant



Figure 11. Oil Filter Severely Contaminated with CoolantInspect the oil filter for physical damage or tears to the pleats. A damaged or torn oil filter may allow unfiltered oil into theclean side of the lubrication system. If the bearing failure is caused by debris, a damaged oil filter may be at fault. It isimportant to note an oil filter does not get damaged on its own. Investigate further to determine how the damage occurred.

It is also important to inspect the oil filter for indications of run time. If the oil filter appears new or very recently replaced,investigate the previous oil change event to determine if it is related to the failure. The lower end bearings should beinspected for lack of lubrication or debris before an oil change event is blamed for the failure.

Oil Filter Standpipe and Bypass Valve

The oil filter standpipe is made of plastic and contains the oil filter bypass valve (1). See figure below. The bypass circuit isrequired to prevent oil filter pleat damage at cold engine start. The next figure shows a cutaway of the oil filter standpipe andthe operation of the bypass valve.



1. Bypass ValveFigure 12. Oil Filter Standpipe and Bypass Valve

Figure 13. Oil Filter Bypass Valve Operation (cutaway)When the engine is cold, a portion of the engine lubricating oil from the oil sump will bypass the oil filter and be delivered tothe various components in the lube oil circuit, including the lower end bearings. Any debris that is small enough to make it



through the oil suction manifold strainer, oil pump, oil cooler, and bypass valve can end up in the bearings due to cold oilfilter bypass. For this reason, it is important to make clean repairs to the engine so debris is avoided. It is also important tofollow the proper sequence for an oil change; oil filter first, then drain the oil pan. This allows any contaminants from the oilfilter to drain back to the oil pan and be removed with the dirty engine oil.

The oil filter bypass valve can be damaged during an oil filter change if care is not used when removing and installing the oilfilter and cap. See figure below. The bypass valve can also become stuck open from foreign debris or engine parts. See figurebelow. Operating an engine with a missing, damaged or stuck open oil filter bypass valve could result in a debris-related,lower end bearing failure due to a larger amount of unfiltered oil entering the clean side of the lubricating system.

1. Broken Bypass ValveFigure 14. Broken and Missing Oil Filter Bypass Valve



1. Foreign Material / Sealing RingFigure 15. Stuck Open Oil Filter Bypass Valve



8 Checking for Contaminated Lubricating Oil

1. Drain the engine lubricating oil into a clean, suitable drain pan.2. Remove one quart of drained oil and place into a clear container. Allow the oil to sit and check for any separation,

indicating contamination. Coolant contamination is typically the result of a cracked (scuffed) cylinder liner or headgasket grommet failure. The cooling system should be pressurized to find the origin of the leak. Fuel contamination isless likely, but can be the result of a loose, cracked or heavily overfueling injector. Although rare, it can also be theresult of failed fuel and oil seals in the high pressure fuel pump. The fuel system should be pressurized to find the originof the leak. If coolant or fuel contamination caused the lower end bearing failure, the origin of the leak must be found todetermine the correct PFP and determine warranty eligibility.

An oil sample may only be beneficial for determining contamination, due to the large amount of bearing debris as a result ofthe failure.

Clean, fresh lubricating oil is an indication of a very recent oil change. Make a note if this is found.

Also note any abnormal debris found in the lube oil and retain the debris. Refer to the next section for further information ondebris.

8 Checking for Contaminated Lubricating Oil


9 Debris in the Oil Pan

Remove the oil pan and inspect for debris. There will typically be bearing material in the oil and oil pan if a lower-end failureoccurs.

Check for foreign material that should not be present such as:

Bolts, nuts or screws Ball bearings or tapered roller bearings from an Axial Power Turbine (APT) gear box APT bearing material (brass sleeve style bearings) Turbocharger bearing material (brass sleeve style bearings) Teeth from the gear train Metal pieces from an injector harness Debris left from a previous repair (shop towels, tools, thread repair material, protective covers, etc.)

The following illustrations show some examples of debris:

1. Tapered Roller BearingsFigure 16. Axial Power Turbine Gear Box Tapered Roller Bearings in Oil Pan



Figure 17. Turbocharger Shaft Bearing Found in the Oil PanSome debris may actually leave a witness mark in the oil pan or on the screen of the oil suction manifold. Make note of thedebris found, as it can relate to the lower end bearing failure.

When the oil pan is removed, inspect for abnormal conditions or recent repairs and note them. The engine is built using graysealant on the corners of the oil pan. Other colors of sealant would indicate the oil pan has been removed after the truck wasput into service. Rounded bolt heads are also an indication of previous repairs.

Rust on the inside of the cylinder block and main caps indicates the presence of water in the oil. The truck may have beeninvolved in a flood. Further investigation is needed.

9 Debris in the Oil Pan


10 Oil Pump and Oil Suction Manifold Inspection

Remove the oil pump, oil lines and oil suction manifold. Lay the parts out on a suitable table for inspection.

Inspect the oil pump for cracks in the housing, loose mounting bolts, damage to the drive gear, or loose regulator and reliefvalves. Damage to the drive gear or a cracked oil pump body may indicate debris was present between the drive gear and thecrankshaft gear at some point. The oil pump would be a secondary failure. If the oil pump is seized with no external damage,disassemble the pump and check for damaged gears or the presence of debris.

1. Oil Pressure Regulator 2. Oil Pressure ReliefFigure 18. Oil Pump Pressure Regulator and Pressure Relief Valves



1. Cracks in Oil PumpFigure 19. Damaged Oil Pump BodyInspect the oil suction and pressure lines for cracks or other physical damage. Higher mileage engines may have flat and/orbrittle O-rings. There will be a history of low oil pressure codes if the O-rings have failed, causing oil starvation to thebearings. Failed O-rings will damage only the rod bearings, not the mains. If the main bearings are also damaged, the O-ringsby themselves are not the PFP.

Inspect the oil suction manifold for cracks and loose mounting bolts. Check the inlet screen for damage and make sure it isstill attached to the suction manifold. Check for any loose, broken or missing plastic pieces that may result in an oil starvationissue. See illustrations below.

10 Oil Pump and Oil Suction Manifold Inspection


1. Location of Missing CapFigure 20. Missing Plastic Cap from Oil Suction Manifold

Figure 21. Missing Cap from Oil Suction Manifold found in Oil Pan



11 Sputtered Bearing Description and Operation

The loaded half of the main and connecting rod bearings in DD Platform engines are a sputtered design. These can beidentified by a dark gray-colored top layer. Sputtered bearings are capable of supporting the very high loads associated withthe increased cylinder pressures of this engine. These bearings' shells use the same general structure as a standard tri-metalbearing. However, the bearings are enhanced by an aluminum layer that is deposited onto the bearing material by a specialproduction method known as the sputter process. The sputtered layer is extremely hard and wear-resistant for a long servicelife, under normal operating conditions.

1. Sputtered Overlay2. Barrier

3. Lining4. Backing

Figure 22. Sputtered Bearing Construction (Thickness of Layers may vary)A side effect of the hard, sputtered top layer is reduced embedability. Embedability is the ability of the bearing to absorbforeign material without causing serious engine damage. This is the reason why DD engines must be kept free from debrisduring operation and repair. Power abrasive tools and abrasive cleaning methods must not be used when preparing gasketsealing surfaces. That level of cleaning with the gasket and seal materials is unnecessary for DD engines. Drilling andtapping any opening on the clean side of the lubrication system must also be avoided. These repair methods are known tocause lower end bearing failures by introducing debris into the main oil gallery.

11 Sputtered Bearing Description and Operation


1. Marks from Using an Abrasive Cleaning DiskFigure 23. Evidence of Power Abrasive Cleaning on the Oil Coolant Module Sealing Surface



12 Lower End Bearing Inspection

Remove and lay out as many main and rod bearings as possible for review. The bearing caps should be laid out and labeledby location. See figure below. A similar setup for the rod bearings is recommended. Clean the oil from the bearings but becareful not to disturb any physical evidence.

The purpose of this section is to lay out the bearings and compare the physical evidence with the descriptions and illustrationsin the next section to determine the bearing failure type. Once the bearing failure type has been identified, the root cause ofthe failure or PFP should be easy to find in most cases. The PFP must be linked with the bearing failure type. For example, ifthe oil filter bypass valve is broken and missing and the bearings show a debris failure, the bypass valve is the logical causeof the bearing failure.

Figure 24. Main Bearing Inspection Layout



Figure 25. High Mileage Main Bearings - Normal Wear

Figure 26. High Mileage Rod Bearings - Normal WearIf a rod bearing is spun or a single rod is out of the cylinder block, there is a chance the main bearing feeding oil to that rod isspun. See figure below.



1. Spun Main Bearing 2. Spun Rod BearingFigure 27. Spun Main Bearing Resulting in Spun Rod Bearing

Figure 28. Single Rod out of the Cylinder BlockRefer to the next section for lower end bearing failure types.



13 Types of Lower End Bearing Failures

There are four different failure modes for lower end bearings: Debris Contaminated Lube Oil Oil Starvation or Lack of Lubrication Misassembly

Debris

Debris failure is the most common failure mode for lower end bearings on any engine. The bearing will show lines of lightscratches or deep grooves. Specks from embedded material may be present. Spots of exposed copper may appear if thescoring is deep. Damage can be shown across all main and rod bearings or as an isolated failure.

1. Journal2. Bearing Top Layer3. Bearing Backing

4. Oil Clearance5. Debris Particle6. Displaced Bearing Material

Figure 29. Debris ContaminationBecause the top layer of a sputtered bearing is very hard, debris is less likely to be captured (embedded) in the bearing. Thedebris may score the bearing and get stuck in the oil clearance area between the bearing and the crankshaft journal. The oilclearance area is very small and any debris caught in this area can lead to the bearing shell spinning in its bore.

Below are some examples of lower end bearings damaged by debris:



Figure 30. Bearings Scored from Debris

Figure 31. Debris Causing a Spun Main Bearing



Figure 32. Debris Across All Main Bearings

Figure 33. Debris ScoringAs discussed in previous sections, even debris before the oil filter can enter the clean side of the lubrication system duringcold oil filter bypass. This is why it is crucial to keep the engine as clean as possible during operation and repair.



Possible causes of debris that could damage the lower end bearings:

Debris from a damaged or incorrect oil filter Broken and missing oil filter bypass valve A dirty repair resulting in the creation of debris:

- Failure to clean the area prior to a repair- Failure to cover critical openings exposing the lube system or oil drains- Using abrasive cleaning methods (should be evidence on sealing surface)- Thread repair- Drilling and tapping oil passages

Internal debris from a previous failure such as:- Turbocharger bearings- Axial Power Turbine (APT) or gear box bearings- Geartrain failure- Air compressor failure

Improper sequence for an oil change

If the oil is changed before the oil filter is changed, debris from the filter drainback can contaminate the oil pan and new lubeoil. The oil filter must be changed first and then the lubricating oil is changed. This is a common practice for most cartridge-style oil filters.

Debris failures require a careful investigation to determine the root cause. Repair history and physical evidence are veryimportant. Even small things should not be overlooked.

Contaminated Lube Oil

Contaminated lube oil is very destructive to the lower end bearings. Coolant, water and fuel do not provide the requiredlubricity needed for engine operation. Visible damage to the bearings can vary depending on the amount of contaminationand engine run time. Damage can range from missing sections of the sputtered layer to smearing of the complete bearingsurface. Examples are shown below.

Figure 34. Bearings with Missing Sputtered Layer



Figure 35. Smeared BearingsThere should be indicators of coolant or fuel contamination prior to the bearing inspection. These include visual signs orsmell of the drained lube oil and visual signs of the oil filter (coolant). There may be a history of low coolant level or low oilpressure codes. Repair history could also be helpful to determine if a prior repair was made to correct a coolant or fuelcontamination source. Refer to sections "Oil Filter and Oil Filter Standpipe Inspection," "Checking for ContaminatedLubricating Oil" and "Gathering and Interpreting Electronic Information" in this guide.

Possible sources of coolant contamination:

Scuffed cylinder with a cracked liner Failed cylinder head gasket grommet seals resulting in coolant contamination of the oil drainbacks Failed oil cooler core (rare) Crack or porosity in the cylinder block, cylinder head or oil coolant module allowing cross-contamination (rare)

Possible sources of fuel contamination:

Loose, cracked or severely overfueling injector Failed fuel and oil seals in the high pressure fuel pump allowing fuel to enter the crankcase at the geartrain (rare)

The source of the contamination must be found to determine the Primary Failed Part (PFP).

Oil Starvation or Lack of Lubrication

A proper oil film between the bearing shell and the crankshaft journal is required for long bearing and crankshaft service life.See figure below.



Figure 36. Oil Film LevelsMinor oil starvation will show up as a scuff mark in the center of the bearing shell. See figure below. The rod bearings have ahigher unit load than the main bearings and will tend to mark first when exposed to an oil supply issue. This is common withan engine that momentarily ran backwards from a failed fuel injector. This is also common with failed higher mileage oil lineO-rings.

Figure 37. Minor Oil Starvation



Continued operation of the engine with an oil starvation condition can cause significant bearing damage or a rod out of theblock. Damage from severe oil starvation or lack of lubrication will appear as a wiped bearing surface. See figures below.Wiping occurs when the bearing and journal have come into direct contact with each other from lack of oil film. Wipingproduces high heat from friction between the two surfaces.

Figure 38. Wiped Bearing Surfaces from Lack of Lubrication



Figure 39. Wiped Bearing SurfaceIn some cases, severe lack of lubrication can result in bearing layers that appear to be melted with the layer material streakingtogether, shown below.

Figure 40. Severe Lack of Lubrication



Most instances of wiping from severe oil starvation or lack of lubrication will appear as a systematic problem across ALLbearings. Plugged oil passages are the only possibility for an isolated lack of lubrication condition.

Possible causes of oil starvation or lack of lubrication:

Damaged oil supply system (oil pump, oil lines or oil suction manifold) Backwards running engine Starvation from an accident or rollover Oil change event (oil not added) Gross engine oil leak Operating with a low oil level Poor lube oil condition Improper lube oil Plugged oil passage

There may be a history of low oil pressure faults for an engine that failed due to oil starvation or lack of lubrication.

If the bearing failure occurred during, or immediately following, an oil change with low oil pressure codes logged, it is verylikely oil was not added before the engine was started.

Misassembled

Assembly issues typically show up within 12,000 miles of initial assembly or repair and will usually result in a single,isolated failure. These failures include a spun main bearing, spun rod bearing or rod out of the block. Remember that if amain bearing spins, the rod bearing it feeds will be starved of oil and will also suffer damage if the engine continues to beoperated.

Misassembled failures could occur from:

Debris trapped between the bearing shell and bearing cap Debris trapped between the bearing shell and crankshaft journal Incorrect assembly of connecting rod bearing cap and connecting rod

- Mismatch of rod caps- Incorrect rod cap alignment (cap reversed)- Improper torque (under- or over-torque)

Incorrect assembly of main bearing cap and cylinder block- Mismatch of main caps- Improper torque (under- or over-torque)

Incorrect assembly of main or rod bearing shells- Misalignment- Incorrectly positioned

Under-torque of main or connecting rod bearing cap bolts will typically result in a spun bearing. An under-torque conditionmay show up as chatter marks on the backside of the failed bearing shell as the shell is allowed to move up and down in thecap while it spins.

Examples of misassembled failures are shown in the figures below.



1. Chatter MarksFigure 41. Chatter Marks in the Bearing Shell from Loose Bearing Cap Bolts

1. Bearing Shell2. Cylinder Block or Connecting Rod

3. Foreign Material4. Crankshaft

Figure 42. Debris trapped under Bearing Shell



Figure 43. Bearing Shell showing trapped DebrisContinued operation with a spun connecting rod bearing (for any reason) will often lead to a connecting rod exiting thecylinder block. Once the bearing shell starts to lose material, it creates additional clearance between the cap and thecrankshaft journal. As the engine operates and the connecting rod travels to Top Dead Center (TDC), this extra clearance andthe weight of the rod and piston assembly causes the connecting rod bolts to stretch. Eventually, a stretched bolt will eithersnap or come loose and end up in the oil pan. In both situations, the connecting rod becomes disconnected from thecrankshaft journal and will then exit the cylinder block through the wall of the crankcase. See figure below showing partsretrieved after the failure.



Figure 44. Connecting Rod Cap, Bolts and Bearing Shell after Failure



14 Vertical Failure vs. Horizontal Failure

There are two general failure modes for the DD Platform engine; vertical failure and horizontal failure. Knowing thedifference between the two can help when trying to determine root cause.

A vertical or isolated failure involves a single component:

Fuel Injector Rocker arm / engine brake Intake or exhaust valve Single main or rod bearing Scuffed cylinder

Horizontal or system failures have more than one of the same components damaged or failed:

Multiple main bearings Multiple rod bearings Multiple scuffed cylinders Engine overspeed condition Engine overheat condition Systematic air-fuel ratio related failures

1. A = Vertical (Isolated) Failure 2. B = Horizontal (Systemic) Failure



Figure 45. Vertical vs. Horizontal FailureAs an example, a single main or rod bearing failure is being investigated. All of the other main and rod bearings show normalwear. Knowing this is a vertical (isolated) failure can already help rule out a systematic problem such as contaminated lubeoil.

Figure 46. Single Rod Bearing Failure

14 Vertical Failure vs. Horizontal Failure


15 Probability of a Defect

Figure 47. Probability of a DefectFailures due to initial assembly quality will usually manifest within 12,000 miles of use. The higher the mileage or time inservice, the less likely the failure will be the result of initial assembly or a material defect. Higher mileage failures are morelikely the result of poor maintenance practices, improper use of the equipment, accidents, or improper workmanship during arepair. However, it is not impossible to have a higher mileage failure caused by initial assembly or a material defect; thatscenario is much less likely.



16 Failure Scenarios

Now that all of the bearing failure modes have been presented, here are some sample scenarios to help draw it all together.

Scenario 1

A truck enters the shop with the engine locked up. It will not bar over. Upon investigation, the technician finds a spun mainbearing. All of the main and rod bearings show scratches and scoring from debris. The oil filter is not damaged and is correctfor a DD engine. However, the oil filter bypass valve and spring are missing. The missing bypass valve is the Primary FailedPart (PFP). The bypass valve was very likely damaged and /or dislodged during a recent oil filter service. This failure is dueto improper workmanship.

Scenario 2

A unit is towed in with a lower end knock. The oil pan is removed and the technician finds a spun rod bearing. Most of thebearings show smearing. The technician also notices signs of coolant in the oil and a coolant saturated oil filter. There arelow coolant level codes and low oil pressure codes present when DiagnosticLink is connected. The coolant contamination ledto the bearing failure. The cooling system is pressurized and coolant is leaking down the inside of a cylinder liner. Thetechnician finds the liner is cracked from scuffing. The root cause of the liner scuffing must be found to establish the truePFP.

Scenario 3

A unit has a vibration at idle. The technician finds a spun number seven main bearing. There are some signs of debris in thefailed bearing shell. All of the other main and rod bearings show normal wear. There are no fault codes. Warranty historyshows the cup plug below the high pressure fuel pump was replaced for an oil leak 50 miles ago. The previous repair shophad drilled and tapped the cylinder block and installed a threaded plug. This exposed the number seven main oil feed todebris. The debris caused an isolated failure of number seven main bearing. Drilling and tapping any oil passage in thecylinder block or cylinder head is not recommended. This failure would be considered improper workmanship.

Scenario 4

A truck enters the shop with a lower end knocking complaint. Several bearings show scoring from debris. There is also aspun rod bearing. Upon inspection, the technician finds an MBE 4000 oil filter was installed on a DD platform engine and theoil filter bypass valve is broken and missing. This failure would be considered improper workmanship.

Scenario 5

A low mileage (less than 12,000 miles) unit arrives at the shop with a connecting rod out of the cylinder block. All of theother lower end bearings show normal wear. There are no engine overspeed events. There are no signs of contaminated lubeand no issues are found with the oil filter, oil filter bypass valve, oil pump, oil lines or oil suction manifold. No repairs havebeen made to the engine per the Detroit warranty history and there are no physical signs of previous repairs. The failed rodbearing shell is inspected. There are some chatter marks on the backside of the bearing. This is a sign the rod bolts were notproperly torqued during assembly.

Scenario 6

A truck is towed to the shop with a locked-up engine. Several main bearings are spun. There are signs of wiping (lack oflubrication) on most of the other bearings. The lube oil looks fresh, as does the oil filter. There are recent, low oil pressurecodes stored in the Motor Control Module (MCM). The truck is equipped with Virtual Technician (VT). The VT Dashboardis accessed and also confirms the low oil pressure codes. In addition, it shows the geographical location where the fault codewas logged. The low oil pressure code was logged at an oil change facility. This, most likely, is a situation where someoneforgot to fill the engine with lubricating oil before starting. This failure would be considered improper workmanship.

Scenario 7

A customer complains of a seized engine. Two spun main bearings are found. There is debris damage across all main and rodbearings. Detroit warranty history shows a recent repair (within 90 days) for stripped rocker cover bolt holes in the camshafthousing. The camshaft housing was repaired with thread inserts. The technician removes the rocker cover and findsaluminum material on top of the cylinder head from the thread repair. There is also some aluminum debris in the oil pan. Thisindicates that the dirty repair led to aluminum debris being pulled into the lube circuit and past the oil filter during cold oil

16 Failure Scenarios


filter bypass. This failure would be considered improper workmanship. Great care must be taken to ensure debris does notenter the engine during repairs.

Scenario 8

A truck was towed to a shop for a crank no start complaint. There are Rail Pressure and Low Oil Pressure codes. The LowOil Pressure codes require lower end bearing inspection. The technician finds wiping from lack of lubrication on most of theconnecting rod bearings. The rod journals on the crankshaft are damaged from bearing material transfer. Further inspection ofthe fresh air intake system shows soot from the engine running backwards. The fuel filters were removed and allowed to sitout. Crystals formed as the filters dried. There was also a rusty brown coating on the inside of the fuel filter module. Thetechnician reviews the "Diesel Exhaust Fluid in Fuel" diagnostic from the service literature and decides there is, in fact, DEFcontamination in the fuel system. The DEF caused a fuel injector failure (stuck open), which then led to the engine runningbackwards at start up. The oil pump ran backwards and led to a lack of lubrication, which damaged the connecting rodbearings and crankshaft.

Scenario 9

A customer complains of a lower-end knock. The technician finds a spun rod bearing and most of the other bearings showsigns of debris scoring. There are no fault codes. No other issues are found during component inspection. Warranty history isreviewed and there is a recent (within 90 days) repair for oil coolant module gasket replacement. The oil coolant module isremoved and the technician finds that the sealing surface on the cylinder block has been incorrectly conditioned by anabrasive cleaning method. The main oil gallery is open to debris once the module is removed. Abrasive cleaning methods arenot recommended. This failure would be considered improper workmanship.

Scenario 10

A unit is towed for a seized engine. The technician discovers a spun main bearing and most other bearings show wiping andlack of lubrication. There are no fault codes stored and no related warranty repairs. A vehicle inspection reveals recent paintwork on the cab and fairings. The hood is new, as well as the oil pan. The driver of the truck says the truck was recentlyinvolved in a roll-over accident. The repairing collision shop is contacted and they do not have any records of the lower endbearings being inspected. The bearings should be inspected in the case of an accident where oil starvation may have occurred,even if there are NO Low Oil Pressure codes. Failures due to an accident, misuse, misapplication, storage damage, negligenceor modification exceeding Detroit specifications, are NOT eligible for warranty.



17 Conclusion

Much information is provided in this guide about DD Platform lower end bearing failures. This information is sufficient tofind the root cause (PFP) of the failure in most cases. Remember that the PFP determines the warranty eligibility.

17 Conclusion


18 Glossary of Terms

Table 1.Aluminum Contamination Introduction of aluminum into the engine lubrication system caused

by failure of an aluminum component or debris introduced during arepair.

Bearing Cap The removable half of the housing that holds the bearing shells inplace.

Bearing Lower (Half Shell) The bearing half that is made for assembly in the bearing cap.

Bearing Housing Bore The housing into which the bearing shells are assembled.

Bearing Upper (Half Shell) The bearing half that is made for assembly in the engine block orconnecting rod as opposed to the bearing cap.

Bore (Housing) The inside diameter of the main bearing/connecting rod bore intowhich the bearing shells are assembled.

Clearance (Bearing) The difference between the bearing housing bore Inside Diameter(ID) and the bearing journal Outside Diameter (OD).

Copper Exposed A condition where the bearing shell has been worn through theoverlay and into the copper bearing lining as evidenced by a coppercolor.

Crankcase The enclosure for the crankshaft formed by the oil pan and the lowerportion of the engine block.

Dilution Either fuel or coolant in the lubrication system mixing with thelubrication oil.

Embedability The ability of the bearing material to absorb foreign material withoutcausing serious bearing damage.

Embedded The enclosure of solid particles into the surface of a bearing shell;i.e., dirt, shavings, other foreign material.

Fatigue Strength The ability of a bearing material to withstand the repeated loadsduring engine operation.

Foreign Material Any extraneous material not intended to be present, i.e., particles ofsteel, cast iron, aluminum, dirt, plastic, etc.

Insufficient Lubrication Inadequate flow rate of the lubrication oil for satisfactoryperformance.

Journal The part of a shaft that revolves in a bearing.

Limit A size dimension either plus or minus the tolerance (high or lowlimit).

Locating Tang A projection on a bearing back that locates in a machined slot in thebearing seat, used to locate the bearing in the housing bore andkeep it from moving laterally.

Lubricant A substance capable of reducing friction between mating surfaces ina relative motion through separation by an oil film.

Main Bearing Saddle The area in the cylinder block machined to receive the upper mainbearing.

Oil Film The thin layer of oil that protects the journal and bearing surfaces byseparating them and preventing journal to bearing contact while theengine is in operation.

Oil Gallery (Main) The main oil supply line in the engine block, often referred to as theheader. Oil flows from this major supply route under pressure to themany parts that are to be lubricated.



Oil Groove A canal machined in the surface of a bearing to spread oil on afriction area or to permit the transfer of oil to another part.

Oil Hole A hole drilled through the bearing wall or crankshaft journal to allowthe passage of the oil.

Oil Starvation A condition of inadequate oil flow or supply.

Spun Bearing A bearing set which has adhered to the journal and turned in thebore for various reasons, i.e. debris, lack of lubrication, orcontaminated lube.

Wear The gradual decrease in bearing thickness.

18 Glossary of Terms


19 Technician Checklist

1. ___ Driver QuestionnaireNotes: ____________________________________________________________________________________

2. ___ Vehicle and Engine InspectionNotes: ____________________________________________________________________________________

3. ___ Gathering and Interpreting Electronic Informationa. ___ DDEC Reports extracted

Notes: _______________________________________________________________________________b. ___ DiagnosticLink log file obtained

Notes: _______________________________________________________________________________c. ___ Virtual Technician review

Notes: _______________________________________________________________________________d. ___ Detroit Warranty review

Notes: _______________________________________________________________________________4. ___ Oil Filter and Oil Filter Standpipe Inspection

Notes: ____________________________________________________________________________________5. ___ Checking for Contaminated Lubricating Oil

Notes: ____________________________________________________________________________________6. ___ Debris in the Oil Pan

Notes: ____________________________________________________________________________________7. ___ Oil Pump and Oil Suction Manifold Inspection

Notes: ____________________________________________________________________________________8. ___ Lower End Bearing Inspection

Notes: ____________________________________________________________________________________9. ___ Conclusion

a. ___ What is the PFP?Notes: _______________________________________________________________________________

b. ___ Is this a Warranty or a Customer Pay repair?Notes: _______________________________________________________________________________



1 DD Platform Bearing Failure Guide2 A Note on Warranty3 Design of the Engine Lubrication System4 Driver Questionnaire5 Vehicle and Engine Inspection6 Gathering and Interpreting Electronic Information7 Oil Filter and Oil Filter Standpipe Inspection8 Checking for Contaminated Lubricating Oil9 Debris in the Oil Pan10 Oil Pump and Oil Suction Manifold Inspection11 Sputtered Bearing Description and Operation12 Lower End Bearing Inspection13 Types of Lower End Bearing Failures14 Vertical Failure vs. Horizontal Failure15 Probability of a Defect16 Failure Scenarios17 Conclusion18 Glossary of Terms19 Technician Checklist

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