Chapter 03 Bennet

8/10/2019 Chapter 03 Bennet

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Chapter 3

Tools and Fasteners


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Objectives (1 of 2)

List some of the common hand tools used

in heavy-duty truck repair.

Describe how to use common pneumatic,electrical, and hydraulic power tools used

in heavy-duty truck repair.

Identify the mechanical and electronicmeasuring tools used in the heavy-duty

truck shop.


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Objectives (2 of 2)

Describe the proper procedure formeasuring with a micrometer.

Identify the types of manufacturer serviceliterature used in truck repair facilities anddescribe the type of information eachprovides.

Explain the principles and precautions ofworking with various heavy-duty truckfasteners.


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Hand Tools (1 of 2)

Hammer safety

Always wear eye protection when striking

tempered tools and hardened metalsurfaces.

Whenever possible, use soft-faced

hammers when striking hardened surfaces.

Never strike one hammer against another.

Check the fit and condition of the handle.


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Hand Tools (2 of 2)

Replace cracked or splintered handles and do

not use the handle for prying or bumping.

Select the right size for the job. Grip the handle close to the end.

Prevent injuries to others.

Swing in a direction that will not let your hammer

strike someone if it slips from your hand.

Keep the handle dry and free of grease and oil.

Keep the hammer face parallel with your work.


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Saw and Knife Safety (1 of 2)

Keep knife blades sharp.

Cut away from the body.

Never pry with a knife or saw blade.

Store knives safely.


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Saw and Knife Safety (2 of 2)

Before completing a saw cut, slow down to avoid

injury as the saw finishes the cut.

Never use a damaged blade. Always wear safety glasses when using a

hacksaw.

Do not use the thumb as a guide in starting a

hacksaw.

Use full travel, even strokes to maximize the life

of the blade.


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Chisel and Punch Safety

Wear eye protection when cutting with a

chisel or using a punch.

Avoid using a punch or chisel on hardenedmetal.

Grind off mushroom heads before using a

chisel or punch. Do not drive a punch too deep into a bore

or it may become wedged due to its taper.


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Screwdrivers

Standard tip screwdrivers

Phillips screwdrivers

Specialty screwdrivers Safety Use screwdrivers only for turning screws.

A slotted screwdriver tip can easily be dressed toits original shape.

If the screwdriver blade fits the screw slot properly,you will produce maximum torque with minimumeffort.


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Screwdriver Safety

It is a good rule to keep your other hand clear when applyingforce to any type of screwdriver.

Always have the screwdriver and the screw correctly linedup.

Screwdrivers designed for use with wrenches have either asquare shank or a hex bolster at the handle.

Do not hold components in your hand while turning fastenerswith a screwdriver.

When working around anything electrical, use a screwdriverwith an insulated handle and shank to avoid shock and shortcircuits.


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Wrenches

Open-end wrenches

Box-end wrenches

Combination wrenches

Adjustable wrenches

Allen wrenches

Socket wrenches


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Wrench Safety (1 of 2)

Use wrenches that fit.

Wrenches that slip damage bolt heads and nuts,

skin knuckles, and cause the user to fall.

Use the proper wrench to get the job donethe

one that gives you the surest grip and a straight

clean pull.

Do not extend the length of a wrench. Do not use a hammer on wrenches unless they

are designed for that type of use.


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Wrench Safety (2 of 2)

Pull on the wrench.

Use an open palm to push on a wrench

when you cannot pull it toward you. Replace damaged wrenches.

The adjustable wrench is a multi-purpose

tool, but it should never be used if aproperly fitting combination wrench is at

hand.


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Pliers

Combination pliers

Adjustable pliers

Adjustable pliers

Locking pliers

Diagonal cutting pliers


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Plier and Cutter Safety

Do not use pliers as a wrench.

Guard against eye injuries when cutting withpliers or cutters.

Observe the following side-cutter precautions: Select a cutter big enough for the job.

Keep the blades at right angles to the stock.

Do not rock the cutter to get a faster cut.

Adjust the cutters to maintain a small clearancebetween the blades.

Pliers are made for holding, pinching, squeezing,and cuttingnot usually for turning.


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File Safety

Wear eye protection when filing.

Never strike a file with a hammer.

Always cut away from the body.

Never use a file without a securely

attached handle.

Do not use worn (dull) files; replace them.


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Special Tools

Taps and dies

Gear and bearing pullers


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Power Tools Safety (1 of 7)

Return all equipment to its proper place whenfinished.

Wear eye protection.

Noise may be a hazard with some portablepower tools, especially pneumatic tools. Wear hearing protection whenever noise is

excessive.

Wear gloves when operating air chisels or airhammers.

All electrical equipment should be grounded,unless it is the double insulated type.


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Never make adjustments, lubricate, or

clean a machine while it is running.

Do not clean yourself or anyone else withcompressed air.

Report any suspect or malfunctioning

machinery to the instructor or servicemanager.

Know your power tool.


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Do not abuse the electric power cord.

Never yank it to disconnect it from areceptacle.

No machine should be started unlessguards are in place and in good condition.

Check and make all adjustments before

applying power. Give the machine your undivided attention

while you are using it.


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Inspect all equipment for safety and for apparent defectsbefore using.

Whenever safeguards or devices are removed to makerepairs or adjustments, equipment should be turned off andthe main switch locked and tagged.

Start and stop your own machine and remain with it until ithas come to a complete stop.

Always allow any machine to reach operating speed beforeloading it.

No attempt should be made to retard rotation of the tool orwork.


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Do not try to strip broken belts or other

debris from a pulley in motion or reach

between belts and pulleys. Do not use loose rags around operating

machinery.

Use the right tool. Maintain tools with care.


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Remove adjusting keys and wrenches.

Do not overreach.

Maintain a balanced stance to avoid slipping.

Disconnect tools when not in use, beforeservicing, or when changing attachments,blades, bits, cutters, and so on.

Before plugging in any electric tool or machine,make sure the switch is off.

Remove all sharp edges and burrs beforecompleting any job.


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Impact wrenches

Air ratchet wrenches

Air drills

Air chisels and hammers

Blowgun


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Other Power Tools

Bench grinders

Lifts and hoists

Presses


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Lift and Hoist Safety (1 of 2)

Do not let anyone remain in a vehicle when it isbeing raised.

Make certain you know how to operate the

equipment and know its limitations. Never overload a lift, hoist, or jack.

Chain hoists and cranes must be properlyattached to the parts being lifted.

Always use bolts and shackles of sufficientstrength rating to attach the hoist to the objectbeing lifted.


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Lift and Hoist Safety (2 of 2)

Mechanical locks or stands must be engaged

after lifting a truck on any kind of hoist.

Do not use any lift, hoist, or jack that you believe

to be defective or not operating properly.

Make sure all persons and obstructions are clear

before raising or lowering an engine or vehicle.

Avoid working, walking, or standing undersuspended objects that are not mechanically

supported.


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Measuring Tools

Machinists rule

Dial calipers

Micrometers Inside micrometer

Outside micrometer

Depth micrometer


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Reading an Inch-Graduated

Outside Micrometer To read a micrometer, first read the last whole

sleeve number visible on the sleeve index line.

Next, count the number of full sleeve

graduations past the number. Finally, count the number of thimble graduations

past the sleeve graduations.

Add these together for the measurement.

These three readings indicate tenths,hundredths, and thousandths of an inch,respectively.


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Using an Outside Micrometer


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Reading an Inside Micrometer


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Other Measuring Gauges

Thickness gauges

Screw pitch gauges

Torque-indicating wrenches


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Manufacturers

Service Publications Service manuals

Parts books

Service bulletins Recall bulletins

Field service modifications

Time guides

Drivers manuals


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Other Service Publications

Supplier manufacturers guides and

catalogs

General repair literature


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Fasteners

Fastener grades and classes

Frame fasteners

Tightening fasteners Fastener replacement

Thread repair

Screw/stud removers and extractors Thread locking compound application


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Fastener Tightening (1 of 3)

Clean all fasteners, threads, and all surfaces before installingthem.

Ensure they are torqued accurately.

When locking compound or anti-seize compound isrecommended for a fastener, the compound acts as alubricant, and oil is not needed.

Hand turn fasteners so they contact before using a torquewrench to tighten them to their final torque values.

Tighten the nut, not the bolt head, when possible.

This gives a truer torque reading by eliminating bolt bodyfriction.


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Always use a torque wrench to tighten fasteners, and use aslow, smooth, even pull on the wrench.

When reading a bar type torque wrench, look straight downat the scale.

Viewing from an angle can give a false reading.

Only pull on the handle of the torque wrench.

Do not allow the beam of the wrench to touch anything.

Tighten bolts and nuts incrementally.

Typically, this should be to one-half specified torque, tothree-fourth torque, to full torque, and then to full torque asecond time.


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Do not over-torque fasteners.

Overtightening causes permanent stretching offasteners, which can result in breakage of parts or

fasteners. If specific torque values are not given for

countersunk bolts, use the torque value for thecorresponding size and grade of regular bolt.

Follow the torque sequence when provided toensure that clamping forces are even and matingparts and fasteners are not distorted.


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Shop Talk

If a torque-to-yield bolt is replaced with a

new bolt of identical grade but torqued to a

value found in a standard torque chart, theclamping force produced will be at least 25

percent less.

Adh i d


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Adhesives and

Chemical Sealing Materials Chemical adhesives and sealants may provide addedholding force and sealing ability when two components are

joined.

Sealants are applied to threads where fluid contact is

frequent. Chemical thread retainers are either:

Aerobic (cures in the presence of air)

Anaerobic (cures in the absence of air)

When using a chemical adhesive or sealant, follow the

manufacturers instructions. Note that some adhesives molecularly bond to the surface

of metals, destroying the material on removal.


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Shop Talk

To disassemble fasteners that have beenheld together with a thread lockingcompound, it may be necessary to heat

the bond line to 400F before removing thenut.

Every time the fasteners are disassembled,replace them.

If mating components are damaged byoverheating, replace them.


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Summary (1 of 4)

Hand tools are used in many repair tasks.

Proper selection and use of hand tools by the technician areimportant requirements for performing quality heavy-dutytruck service.

Power tools make a technicians job easier. Pneumatic (air) tools have four advantages over electrically

powered equipment: flexibility, light weight, safety, and lowcost operation and maintenance.

The disadvantage is the noise produced.

Power tool safety rules must be followed and that includeswearing hearing protection.


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Summary (2 of 4)

The power tools used in heavy-duty truck repair includeimpact wrenches, air ratchet wrenches, air drills, air chiselsand hammers, blowguns, bench grinders, grinding wheels,wire wheel brushes, buffing wheels, presses, and lifts and

hoists. Using jacks, lifts, frame machines, and hoists to raise trucks,

trailers, or heavy parts on a truck chassis requires carefuladherence to safety rules.

The machinists rule looks like an ordinary ruler, but it is

precisely divided into small increments, either in metric ordecimal graduations.


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Summary (3 of 4)

Dial or digital calipers are used for taking inside, outside,depth, and step measurements, and are calibrated to read ineither metric or standard scales.

A micrometer is used for measuring the inside or outside

diameter of a shaft or the bore of a hole, either in metric orstandard units.

Gauges are used to measure thickness and screw pitch.

A torque wrench is used to measure the amount of twistingforce applied in tightening a fastener.

The main source of repair and specification information forheavy-duty trucks is the OEM service literature available inmanuals, on CDs, or on-line from manufacturer data hubs.


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Summary (4 of 4)

Troubleshooting charts are provided in manuals or on-line toprovide a way to systematically track problem sources andidentify the repair required.

Fasteners used on heavy-duty trucks come in a range of

grades and classes. Proper use of torque wrenches is necessary when installing

threaded fasteners.

The correct fastener is important. In some cases, threadsmust be repaired with thread inserts or by thread chasing.

Rivets are used to fasten overlapping skin panels on a truckcab and some trailer skins.

A rivet gun and bucking bar are used to drive and buckrivets.

Chapter 03 Bennet

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