®

NEWSVolume 4, Issue 2 / Second Quarter, 1996

In this issue...• Our Troubleshooter featurearticle will clear up confusion overFord's AX4N transmission.

• New Ford CD4E servo coverprovides better sealing capability.See cover article.

• Chrysler replaces clutch seals onA604 and A606 transaxles withViton D-rings. See cover article.

• Design change made to GM4T80E Low & Reverse Lathe CutSeal. See cover article.

• GM 4T60E servo cover sealchange. See page 2.

• Subaru 4-speed low/reverseouter piston seal. See page 2.

• Another change made to GM4L80E Lower Valve Body Gasket.See page 7.

• Subaru redesigns 4-speed FrontCase Gasket. See page 7.

from

Ford CD4E 2-4 Servo Cover Provides Better SealingFord has replaced the servo cover on itsearly-design CD4E transaxles with anew cover that is stepped on the outsidediameter to provide better sealing.

Chrysler has replaced the inner andouter lip seals on the 2nd & 4th clutchpiston with Viton D-ring seals. The D-rings will retrofit all 604 and 606transaxles.

Chrysler Replaces Clutch Seals on 41TE (A604)and 42LE (A606) with Viton D-Rings

The lip seals can still be used, butthey will no longer be available oncestock is depleted. All gasket kits andoverhaul kits with a date code of E96 orlater will contain the D-rings.

Lip Seal D-Ring

TransTec # OEM # TransTec # OEM #

Outer Seal 28191 4412245 26677 4659374

Inner Seal 28192 4412246 26678 4659376

lst Design Servo Cover

NoStep

2nd Design Servo Cover

Step

These transaxles had a cap that in-stalled on the outside of the 2-4 servocover snap ring that is no longerrequired and should be discarded.

The old design cover should bereplaced with the new cover, TransTecpart #81673 (OEM #F4RZ-7D027-A).The new servo cover will be included inall TransTec overhaul kits with a datecode of E96 and later.

2/4 ServoReturnSpring

IdentificationGroove Area

PistonRod

ServoCover

RetainingRing

2-4 Servo

CoverCapDISCARD

2/4ServoPiston

4T80E Low & ReverseLathe Cut SealGM has changed the design of its4T80E low and reverse apply servoseals from a lip seal design to a D-ringon the outer seal location.

The new seal, TransTec #25105(OEM #24200747), will be included inkits built with a date code of C96 andlater. This new D-ring seal will retrofitall early built units using the lip seal.

Low/ReverseOuter Seal..Changed toD-Ring

REBUILDER

CASE SEAL POCKET CASE SEAL POCKET

PREVIOUS DESIGN1991 - 2/20/95

NEW DESIGN2/20/95 - 1996

SEAL SEAL

.066" .066"

.551"

.066" .132"

.551"

.054" .112"

2

Denny Scher, Editor

Rebuilder News is dedicated to providing current technical information to the automatictransmission rebuilder. Reader's comments/suggestions are welcomed. Write: Editor,Rebuilder News, P.O. Box 556, Milan, Ohio 44846-0556. © 1996 Freudenberg-NOKGeneral Partnership. All rights reserved. Reproduction without prior written permission isprohibited.

NEWS

Starting on February 20, 1995, GMmade a running change on the 4T60E2-1 manual servo cover seal, changingthe axial thickness, or height of theseal, from .066" to .132". At the sametime, the depth of the pocket in thetransaxle case was changed from .054"to .112".

The seals and cases cannot be inter-

GM 4T60E Servo Cover Seal Changechanged! The new seal must be used incases with a .112" pocket, and theprevious seal in cases with a .054"pocket.

The new seal, part #25104 (OEM#24204386), is included in all gasketkits and overhaul kits starting with datecode E96.

Beginning in early 1992, Subaru made

a design change in the low and reverse

piston outer seal. The previous design

was a lip seal, TransTec #28255 (OEM

#31546-AA000). The current design is

a D-ring seal, TransTec #26683 (OEM

#31616-AA111).

The design change did not occur

across the board in 1992, which has

caused additional confusion. Break

dates between designs vary with model

applications. To accommodate the

change, the low/reverse piston was also

revised. The lip seal and the D-ring

seal will not interchange. Replace the

old seal with a new seal of the same

design. All TransTec kits with a date

code of E96 or later will contain both

seals.

Subaru 4-SpeedLow/ReverseOuter Piston Seal

Subaru 4-SpeedRevised Low/Reverse

Piston Seals

Noteunder cut

Previous Design

New Design

Seal and PocketLocation in Case

Illustration for reference only.

REBUILDER

® TROUBLESHOOTER

FORD's AX4N...Clearing Up Some of the ConfusionBy Bob Bodossian, TransTec Transmission Product Engineer

3

From all the calls I’ve received aboutFord's AX4N transmission, two thingsare readily apparent. First of all, quitea few of these units were showing upin shops not long after they were inproduction. While this may not begood news for Ford, it probably won’tmake anyone in the aftermarket toounhappy. Second, I found that a lotof guys weren’t sure whether theywere looking at an AX4N, AX4S, oran AXODE.

All the Confusion is Understandable

The AX4N was first used in 1995in all Lincoln Continentals, plus someTaurus and Sable models. Just oneyear prior to that, Ford changed thedesignation of the AXODE to AX4S,and a lot of people thought that boththe 4S and 4N were new units.

Confusion grew with the TaurusSHO version of the AX4S called theAX4SH, which was used in 1993-95.Then in 1996, the SHO got a new 3.4litre V-8 engine with the AX4N trans,instead of the AX4SH.

As confusing as all this sounds, it’sreally very easy to tell an AX4N froman AX4S. For starters, the side coveron the AX4N has “AX4N” stamped onit in big letters. The AX4S does nothave any indentification on the sidecover. You don’t even have to knowwhat a transmission looks like tofigure that out.

Looking closer, you’ll notice thatthere is no low-intermediate servo

cover on the outside of the AX4N, andthere isn't a governor cover as found onthe AX4S. Instead, there's a hole in thecase where the output speed sensorgoes.

What's Good for GM is Good for Ford

Basically, Ford has done the same

thing to the AX4S (AXODE) that

General Motors did to the 4T60

(TH440) when they introduced the

4T60E in 1991. The low-intermediate

band has been replaced by a low-

intermediate clutch pack and one-way

roller clutch. This was done to elimi-

nate shift timing pro-

blems associated with

releasing the low-

intermediate band and

applying the direct

clutch during the 2-3

shift in the AX4S.

In the AX4N, the

low-intermediate

clutch stays applied

and the roller clutch

just free-wheels when

the trans shifts from

2nd to 3rd. Thus, the

release of one friction

element and the application of another

doesn’t have to be synchronized.

That’s the meaning behind the designa-

tions AX4N and AX4S. "N" means

non-synchronous (not-synchronized)

shifts and "S" means synchronous

(synchronized) shifts.

Not Unlike an AXODE...

The AX4N should not present anyproblems to anyone that’s familiar withthe AXODE (AX4S). The driveline ispretty much the same, except for thesection between the differential and thereverse clutch. This is where the low-intermediate clutch replaced the band,as stated earlier. There is also a coastband back there that’s applied only inmanual 1st and 2nd gears to provideengine braking. The servo piston andcover for this band are both bondedrubber. These are accessed from insidethe transaxle pan instead of an externalservo cover like the AX4S. That’s the

reason for the largebulge in the side of theAX4N pan compared tothe AX4S.

Two Pans in TwoYears

Speaking of pans, theAX4N already has twodifferent pans andgaskets for the first twoyears it’s been inproduction. The 1995AX4N used a cork pangasket and the pan hadbuilt-in torque limiters

just like the AX4S. In 1996, the pangasket was changed to an elastomeric(molded plastic & rubber) material.The torque limiters were incorporatedinto the gasket and removed from thepan. You can’t use the cork gasket onthe '96 pan because it will leak, and the

"... it’s really very

easy to tell an

AX4N from an

AX4S. For starters,

the side cover on

the AX4N has

“AX4N” stamped

on it in big letters."

4

elastomeric gasket won’t work on the'95 pan because it won’t fit over thetorque limiters.

I guess what’s good for one pan isgood for another, because the samechange was made on the side coverfrom '95 to '96. But it could havebeen worse. You see, the AX4S alsowent to the elastomeric gaskets in1996. But the pan and side coverbolts were changed from 8mm to6mm, so you have a different AX4Scase for '96 than for '95 due to thesmaller bolts. At least Ford plannedahead and used 6mm bolts from thestart on the AX4N.

One Too Many Seals

Inside the pan, the filter on myAX4N core looked identical to theAX4S filter. However, there were

two orange seals on the filter neckinstead of the usual one. Checking theFord parts catalogdidn’t help clearthings up. It stilllists an o-ring for afilter seal, which weall know hasn’t beenused in many years.

Go Right to theSource

It took a call toWayne Ferrel atFiltran, the O.E.M. supplier of thefilter, to get the facts. Yes, the filterby itself is the same as the AX4S andAXOD/E. But there are three differentfilter seals; a short orange, a tallorange, and a green seal that’s inbetween. Since the filters come with aseal on them, there are three different

part numbers for the filter assembly.The seal is what determines the

location of the filter inthe pan.

The short orange sealis the one we’re all usedto seeing in the AXOD/E’s and most AX4S’s. Itis not used in the AX4Nat all. The tall orangeseal is used in the AX4SHand some AX4N modelswith a deep pan. Thegreen seal is used in all

other AX4N’s and the AX4S starting in'96. A good rule of thumb is to replacethe filter with the same style that wasremoved. (As for my filter having twoshort orange seals, that’s what Fordused initially until the tall orange sealreplaced it.)

Ford Isn't Taking Any Chances

The AX4N has four oil transfertubes (fig. 1), one less than the AX4S.The rear lube and the low-intermediatetubes push into two small metal cladseals that are pressed into the low-intermediate housing. These seals aresimilar to the AX4S rear lube seal, butlarger. Unlike the AX4S, all four ofthese tubes use o-rings at all the otherends for a positive seal. You get thefeeling that after the lube problemswith the AXODE, Ford isn’t taking anychances?

Look Close or Look Out

Moving to the side cover, everythingin there looks about the same as theAX4S. But if you look close, you’llnotice that the shift solenoids arearranged differently. The AX4Narrangement from top to bottom issolenoid 1, 2, and 3. In the AX4S, it’s2, 1, and 3 from top to bottom. Notonly are shift solenoids 1 & 2 reversed,but the solenoid apply timing is alsodifferent between the two transaxles, as

Low-IntermediateClutch Transfer Tube

Rear LubeTransfer Tube

ReverseClutchTransferTube

Low-IntServo Apply Transfer

Tube

Figure 1

A good rule of

thumb is to replace

the filter with the

same style that was

removed.

Oil Tubes

Range Gear Sol. 1 Sol. 2 Sol. 3 Sol. 1 Sol. 2 Sol. 3

P-N Off Off Off Off Off Off

R Reverse Off Off Off Off Off Off

lst Off On Off Off On Off

D 2nd On On Off Off Off Off

3rd Off Off On On Off On

4th On Off On On On On

1st Off On Off Off On Off

D 2nd On On Off Off Off Off

3rd Off Off On On Off Off

L lst Off On Off Off On Off

5

you can see in figure 2. If you’re notcareful here, you could go crazytrying to diagnose shift problems!

Simplified Checkball Locations

Once the valve body is removed,you’ll see that this unit has a total of

six checkballs. Five in the valvebody and one in the oil pump body,

as shown in figure 3. Unlike the

AX4S, which has more variations ofcheckball locations than I care to

remember, the AX4N only has one.

Not much chance of screwing up here.Of course, now that that’s said, Ford

will probably make major changes to

the valve body.

Sticky Gaskets Can Stick You

Speaking of the valve body, here’s a

plates, we cannot include them in anoverhaul kit. So far, there are five

different plates for the AX4N, and we

will make them available separately.By the way, that’s the good news. The

AX4S has also gone to bonded plates

for the valve body and the pump. Todate, there are nine different plates.

Accumulator Locations Worth Noting

When you pull the chain cover offthe AX4N, be sure to note the locations

of the accumulator springs. (See figure4 on next page.) Here again, Ford

changed things around just a bit. The

accumulator nearest the top of the case

Figure 3CheckballLocations

word of caution before you take yourscraper to the main valve body gaskets.

No, they’re not baked on from exces-

sive heat. The gaskets are bonded tothe separator plate at the factory.

While this may be less costly and

easier for production, it raises the costof an overhaul. It also presents a pro-

blem to kit packagers like TransTec.

Due to the cost and the number of

Main Control Valve Body Oil Pump Body

AX4S Solenoids AX4N SolenoidsFigure 2

6

TT

is the 1-2 in both the AX4N andAX4S. That’s where the similarities

end. Not only are the

rest of the accumulatorsswitched around, but the

AX4N has one more

than the AX4S in thechain cover, plus it has

one in the bottom of the

case. Figure 4 showsthe AX4N accumulator

locations in the chain

cover. The N-Daccumulator is in the

bottom of the case.

Similar, But Not Interchangeable

As I said earlier, the rest of thedriveline is pretty much the same asthe AX4S and so is the power flow.The only thing you have to rememberis that the low-intermediate band isgone. In its place is the low-interme-diate clutch, the low-intermediate

one-way clutch, and the coast band.

This doesn’t mean you caninterchange any of the parts in the

drivelines between the AX4S andAX4N. While some parts are identical,

a lot of them have

small differences thatcould be missed if

you're not careful.

For example, let’slook at the direct &

intermediate clutch

drum. The AX4Sused lip seals for both

clutch inner seals.

Then along came theAX4SH in the Taurus

SHO and it had D-rings

for both clutch innerseals. I guess Ford wanted the best of

both worlds for the AX4N. It uses the

lip seal for the direct clutch and theD-ring for the intermediate clutch. In

other words, before you start replacing

any hard parts, make sure they matchwhat you took out.

Fewer Pieces Parts

Speaking of clutch seals, the AX4Nhas very few of them. Every clutch

Every clutch piston

in this unit, except

the reverse clutch,

is a bonded assem-

bly. It looks like all

the OEMs are going

in this direction.

piston in this unit, except the reverse

clutch, is a bonded assembly. It lookslike all the OEMs are going in this

direction. A few years from now, lip

seals will probably be a thing of thepast. It may take a little time for some

guys to get used to replacing all the

pistons on every overhaul, but if youthink about it, it makes sense. After

all, you wouldn’t overhaul a trans and

not replace the lip seals, would you?

Do It Right or Do It Over

The use of molded pistons, moldedrubber gaskets, and bonded valvebody gasket and plate assemblies isbecoming more and more common.Some of you are probably thinkingabout how this will raise the cost of anoverhaul, and that it’s easy for me tosay you should replace all these parts.Well, in the 20 years spent at your endof the business, I've learned this. Ifyou explain the cost of a repair to acustomer, they usually don’t like it,but they understand and accept it.What they don't understand is if thejob comes back because you re-used afew parts. The fact that you savedthem $70 or $80 originally doesn’tmean a whole lot at that point.

Cost-Plus Versus Compromise

In most successful businesses, the

price of the product is determined byadding a profit margin to the cost. If

the cost goes up, it is usually passed

on to the consumer. In this business,it seems like we have a lot of people

working in reverse. They set a price

first, and then spend all their timetrying to keep their cost within that

price. I don’t know about you, but

there’s no question in my mind whichapproach I prefer.

Intermediate (1-2) Accumulator

Direct (2-3) Accumulator

Reverse (N-R)Accumulator

Overdrive (3-4) Accumulator

Figure 4 Chain Cover (Transaxle Case Side)

7

Appearing SoonA TransTec representative

will be at the following"Tech Seminars"

Date City State

August 24th Nashville Tennessee

August 31st Denver Colorado

September 7th Detroit Michigan

GM has made another change to thelower valve body gasket for the 4L80Etransmission. The new gasket has anadditional 1-7/8" hole, as shown in the

Change Made to 4L80E Lower Valve Body Gasket

New Gasket - TransTec #12853Previous Gasket - TransTec #12657

illustration below. The previousgasket, TransTec #12657, is beingreplaced by the new gasket, TransTec#12853 (OEM #24201115), which will

NewHole

retrofit all units back through 1991.This gasket will be included in allTransTec kits with a date code of C96or later.

Subaru Redesigns 4-Speed Front Case GasketSubaru has replaced the paper frontcase gasket on its 4-speed transmissionwith a rubber-coated metal gasket. Ifyour transmission has an oil baffle (seeillustration), it should be discarded ifusing the new metal gasket, TransTec#10029 (OEM #31339-AA121). Thebaffle is only used with the papergasket, TransTec #12578 (OEM#31339-AA040).

OilBaffle Plate

Pump Cover

The metal gasket was added tooverhaul kit #2259 starting with datecode A96. The paper gasket willremain in the kit until stock is depleted,at which time it will no longer beavailable.

Caution: Using the paper gasketon a transmission that originally had ametal gasket could cause fluid to leakout of the transmission vent.