More on Torque Bind

[2.5GL]

Regarding those grooves in the second pic above:

 

Are we talking about the 2 grooves on the tops of each tooth, or the 5 on the sides of each tooth? Or both?

 

And you just grind with a Dremel or similar?

 

Asking because I'm sure I'll need to deal with it at some point.

The grooves in question are the five on the leading edge of the hub, typically the worst of the two sides. The top two are insignificant, but can be smoothed as well.

 

I use a small cut-off wheel on a die grinder, a dremel would work too.

 

The solenoid gets replaced as well as smoothing the hub teeth, and the part numbers are...

 

31942AA090 Valve Ay. transfer clutch (This is the one for a majority of vehicles, some early models took a different part #.)

31954AA071 (QTY=2) Gasket for solenoid and plate.

31337AA120 Extension housing gasket

44022AA020 Exh gasket, dual port OR 44011AC020 Single port (if needed)

44022AA062 Exh gasket, large "y" pipe OR 44011AC000 Small pipe (if needed)

11126AA000 Drain plug gasket for tranny

 

Remember.. all this for nothing if your tires do not match Brand, Model, and size. Even though sizes my be the same, tread depth is crutial as well... more than say 2-3/32 difference will cause issues over time.

 

Lewis

 

Edit: remember that the drive hub (top) can be pryed out of the trans, so while smoothing, you can limit the amount of debris into the trans. Take care as there are seals on the shaft that need to be left intact or you're getting new ones. A light coat of trans assembly lube will hold them down during re-assembly.

[nipper]

And if your before 1997 1/2 you need to inspect the complet housing. When Blu got repaired, they replaced the housing too.

 

nipper

[2.5GL]

And if your before 1997 1/2 you need to inspect the complet housing. When Blu got repaired, they replaced the housing too.

 

nipper

 

That would be for the slight grooves found in the housing shown in the last pic, correct?

 

Lewis

[steamin53]

The grooves in question are the five on the leading edge of the hub, typically the worst of the two sides. The top two are insignificant, but can be smoothed as well.

 

I use a small cut-off wheel on a die grinder, a dremel would work too.

 

The solenoid gets replaced as well as smoothing the hub teeth, and the part numbers are...

 

31942AA090 Valve Ay. transfer clutch (This is the one for a majority of vehicles, some early models took a different part #.)

31954AA071 (QTY=2) Gasket for solenoid and plate.

31337AA120 Extension housing gasket

44022AA020 Exh gasket, dual port OR 44011AC020 Single port (if needed)

44022AA062 Exh gasket, large "y" pipe OR 44011AC000 Small pipe (if needed)

11126AA000 Drain plug gasket for tranny

 

Remember.. all this for nothing if your tires do not match Brand, Model, and size. Even though sizes my be the same, tread depth is crutial as well... more than say 2-3/32 difference will cause issues over time.

 

Lewis

 

Edit: remember that the drive hub (top) can be pryed out of the trans, so while smoothing, you can limit the amount of debris into the trans. Take care as there are seals on the shaft that need to be left intact or you're getting new ones. A light coat of trans assembly lube will hold them down during re-assembly.

 

 

Thanks Guys,

 

I'm still a little confused though. It seems that the only way to "smooth" out the grooves is to remove material from the teeth to a depth equal to the deepest part of the groove.

 

If I understand it the problem is that the hydraulic pressure leaks past the clutches via the grooves. If I remove material to smooth them won't that just increase the clearance through which the hydraulic pressure will leak?

 

Please advise.

 

Steve

[steamin53]

Thanks Guys,

 

I'm still a little confused though. It seems that the only way to "smooth" out the grooves is to remove material from the teeth to a depth equal to the deepest part of the groove.

 

If I understand it the problem is that the hydraulic pressure leaks past the clutches via the grooves. If I remove material to smooth them won't that just increase the clearance through which the hydraulic pressure will leak?

 

Please advise.

 

Steve

 

One more question. Are the tailshaft extensions the same for all the 2.5L auto trans vehicles? Mine is a 96. I'm trying to figure out what others might fit so as to possibly get one, rebuild it, and simply replace mine as an assembly. Same concept as posted earlier by someone.

 

Steve

[johnceggleston]

One more question. Are the tailshaft extensions the same for all the 2.5L auto trans vehicles? Mine is a 96. I'm trying to figure out what others might fit so as to possibly get one, rebuild it, and simply replace mine as an assembly. Same concept as posted earlier by someone.

 

Steve

 

i've studied this pretty throughly and i can't give you an absolute answer to that question. i know the same duty c solenoid is used in most if not all years. the big question is wheather the clutch plates/parts are all interchangeable.

 

it is my opinion that they are, but i have no hard evidence of this. (i also think that a legacy rear extention housing is identical to the outback.) if you do look for another rear housing to replace your, i would suggest staying very close to your year, 95 - 98. the auto trans were changed in 99, and i'm not sure i'd go any earlier than 95.

 

i don't know about the 'grooves' or smoothing them out. frankly i was looking at the pictures posted above and was trying to imagine how the power was transfered from the large 'corregated' hub in the first picture to the output shaft. i know there are clutch plates involved, and i know clutch plates grab and release to convey power, but that's about it. i can't even make a guess.

 

i haven't seen any part numbers for clutch plates yet, i don't think. the parts listed above are duty c and gaskets. housing gasket, exhaust gasket (head to y-pipe) and valve assembly gasket (duty c).

 

i swapped a rear housing out of a bad 97 OBW trans into a good 97 OBW trans with torque bind. i knew the rear of the bad trans was good, because i was driving it when the trans failed. i didn't see a lot of wear on the hubs as in the pics above but it was a long time ago and i wasn't looking for it. (both trans were around 100k). i then sold the rear housing with the bad duty c to a member, he installed it with the new duty c and drove away.

 

if i had to guess, and this is just a guess, the marks on the hub pics above are caused by either very high mileage or driving with a failed duty c, torque bind. this puts undue wear on the system. try not to drive with torque bind, pull the rear drive shaft if you have to drive it. this may save your clutch parts.?.?

 

if you put in the FWD fuse and the binding stops, then it's not the duty c. (to be FWD only the duty c has to work.) if the fuse is in and you still have binding ans blinking AT TEMP light at start up, then the duty c solenoid is bad. (maybe more but maybe not)

 

hope this helps,

john

[nipper]

From 96-99 I am 98% sure they are all the same. Subaru replaces anything older then 1997 1/2 with all new parts because of the design flaw, and i really doubt subaru (being a small mfg) has different parts for differnty years. they may tweak the skin, but mechanicals dont go through major changes.

 

nipper

[2.5GL]

As shown in pic #2, the grooves in the hub are caused by the clutches themselves, thus, "wear" occurs over time, and they get stuck in those grooves and are unable to release. This is what happens (the sticking) when the FWD fuse is installed but the binding sensation is still there.

 

In many cases the solenoid is bad as well. Sometimes a simple continuity test shows that it is bad, other times it tends to be temperature related and won't show a problem, or high resistance unless the solenoid is at or near the transmission's operating temperature.

 

I would replace the solenoid and remove grooves on the hub teeth. This point of connection is simply mechanical, no hydraulics involved, no leak to worry about. The grooves in the extension housing (pic #5) are caused from the seals on the output shaft of the transmission. While this may cause some pressure leakage, this would not cause the torque bind as there would be less pressure to the clutches, thus a delay in AWD activation, or a limited amount of operation.

 

Lewis

[johnceggleston]

As shown in pic #2, the grooves in the hub are caused by the clutches themselves, thus, "wear" occurs over time, and they get stuck in those grooves and are unable to release. Lewis

 

obviously something is causing this wear, but i thought the clutch plates were inside of this hub. (the wear marks look like they could be made by stacked plates, but theres no way that can be true.) so the wear must come from this hubs mating with the other hub.?.? again, i have no clue.

 

 

In many cases the solenoid is bad as well. Sometimes a simple continuity test shows that it is bad, other times it tends to be temperature related and won't show a problem, or high resistance unless the solenoid is at or near the transmission's operating temperature. Lewis

 

mine was intermittent at first, somethimes the FWD fuse would relieve the problem and sometimes not. my son claimed the FWD light would go out when he was "really pushing it".

 

 

The grooves in the extension housing (pic #5) are caused from the seals on the output shaft of the transmission. While this may cause some pressure leakage, this would not cause the torque bind as there would be less pressure to the clutches, thus a delay in AWD activation, or a limited amount of operation. Lewis

 

make sense to me.

[2.5GL]

obviously something is causing this wear, but i thought the clutch plates were inside of this hub. (the wear marks look like they could be made by stacked plates, but theres no way that can be true.) so the wear must come from this hubs mating with the other hub.?.? again, i have no clue.

I guess I should have shown a pic with the clutches in place....

 

Pic #3 is the "drum" and a set of "plates" aka "clutches" ride in the drum. Half of those clutches have teeth to the outside, or drum side, the other half to the inside, or hub side-where the grooves are worn into the teeth. (pic #2)

 

When those clutches are compressed by transmission pump pressure they then transmit power from the "drive" shaft of the Auto Trans Box to the "driven" shaft of the extension housing (rear driveline). While accelerating, the clutches dig into the hub and wear a groove into the metal, as time (years) passes, the grooves become deep enough for the clutches to stick into and not release pressure, causing AWD bind-up in tight corners.

 

I could round-up more pics if needed...let me know the relations of parts/views needed.

 

Lewis

[johnceggleston]

I guess I should have shown a pic with the clutches in place....

 

Pic #3 is the "drum" and a set of "plates" aka "clutches" ride in the drum. Half of those clutches have teeth to the outside, or drum side, the other half to the inside, or hub side-where the grooves are worn into the teeth. (pic #2)

 

When those clutches are compressed by transmission pump pressure they then transmit power from the "drive" shaft of the Auto Trans Box to the "driven" shaft of the extension housing (rear driveline). While accelerating, the clutches dig into the hub and wear a groove into the metal, as time (years) passes, the grooves become deep enough for the clutches to stick into and not release pressure, causing AWD bind-up in tight corners.

 

I could round-up more pics if needed...let me know the relations of parts/views needed.

 

Lewis

 

i think i have it now. the clutch plates are not so much like a dinner plate with a hole in the middle as much as they are like a wide ring. they ride out side of one hub(?) and in side the drum. i think i have it now, thanks for your help.

[eseiler]

i think i have it now. the clutch plates are not so much like a dinner plate with a hole in the middle as much as they are like a wide ring. they ride out side of one hub(?) and in side the drum. i think i have it now, thanks for your help.

 

If TB is a mechanical problem, why does resetting/replacing the TCU alleviate the problem (albeit temporarily)?

 

--Damien

[2.5GL]

All I can say is that I have had more luck fixing the mechanical aspects of the binding and replacing the solenoid as good measure-as it ends up being faulty 70% of the time (roughly). IF TB is still present, it will be greatly reduced in severity and then a subsequent R&R of TCU is required to eliminate the irregular duty cycle causing the remaining TB.

 

HOWEVER- if you wish, you can always replace the TCU prior to tearing apart you tranny, you migh "luck-out". but in the long run, mechanical things tend to let you down more than the electronics do with a 4EAT.

 

Lewis

[johnceggleston]

i take it the hub with the grooves worn in it is not easiliy replaceable.

 

http://www.ultimatesubaru.org/forum/attachment.php?attachmentid=5171&d=1187139402

[steamin53]

I guess I should have shown a pic with the clutches in place....

 

 

 

I could round-up more pics if needed...let me know the relations of parts/views needed.

 

Lewis

 

You guys (especially you Lewis) have been terrific in all the experience and help you've provided me and others on this topic. Much more definitive information has come out in this thread than perhaps in all the others I've read.

 

I'd appreciate the additional pics if you can show

 

1. the clutches in place,

 

2. some view of the clutches out of the "drum", and

 

3. a view of the "fixed" hubs once the grooves have been "removed".

 

Also, I read that it's difficult to "realign" the clutches when replacing them. Any experience or tips there?

 

I've found a tranny with 70K miles on it from a donor car that hasn't been wrecked for $425 plus tax. Mine is working well except for the TB but after all it does have over 200K on it now.

 

I plan on pulling the extension housing on the transplant and checking it before installing the tranny. I may or may not change the duty solenoid just for good measure depending on what I find in the way of grooves (assuming that would be an indicator of some solenoid malfunctioning). I imagine that avoiding pulling the housing down to do so after installation would certainly more than balance the cost of the replacing the solenoid befor installation.

[johnceggleston]

you can get the duty c and the 2 gaskets online for less than $80.00 shipped. that does add to the cost of the trans, but the labor to do it later is close to 300$. a 70 trans probably would run for a long time with out replacement but i have sworn never to install a used trans with out replacing the duty c. been burned once allready.

 

i took my 200k donor extention housing apart this weekend and ordered the parts. mine looked exactly like the one in the pics above. i'll be interested to hear if your new one looks any better. apparently the hub with the notches worn into it is securly attached to the drive gear behind it (i've read welded but i'm not sure). otherwise you coul;d replace it as well. but that piece is on the trans not the rear housing so if you are swapping your whole trans you'll get the new used one.

 

let us know how it goes.

[steamin53]

John,

 

You posted this in response to a thread entitled transmission compatibility. I have a question.

 

Originally Posted by johnceggleston

i think in 99, when they went to the phase 2 trans, the impreza and the legacy 2.2 were the same. but i'm not positive. but these years are too late for your match.

 

i'd stick to the legacy / outback models. 2.5L car is preferred, 96 - 98 (some early 99). if you get a trans out of a 2.2L car, you will need the rear differential, (unless it just happens to be a 96 2.2L outback with the trans # TZ102Z2ABA.)

 

these trans should fit:

TZ102Z2ABA = 96 outback (2.2L)

TZ102Z2ABA = 96 outback (2.5L)..... same trans.

 

TZ102Z2CBA = 97 outback...................may need TCU

TZ102Z2CAA = 97 legacy LSi...............may need TCU

TZ102Z2CCA = 97 legacy GT...............may need TCU

 

TZ102Z2DBA = 98 outback (early 99).....may need TCU

TZ102Z2DCA = 98 legacy GT...............may need TCU

 

 

TZ102ZABAA + 96 legacy (all 2.2L cars except outback)........will need rear diff, maybe TCU

TZ102ZACAA + 97 legacy (2.2L)...........will need rear diff, maybe TCU

TZ102ZACAA + 98 legacy (2.2L)...........will need rear diff, maybe TCU

 

the 95 legacy 2.2L trans may work, but there were some other changes that took place that year so unless it was free, i'd stick with 96 - 98.

TZ102ZAAAA + 95 legacy (2.2L)...........will need rear diff, probably TCU

 

i would suggest you search for year and model. find the best deal you can on a 96 outback trans. then look for a 96 GT trans and compare the cost. then look for a 96 LSi trans, then a 97 outback trans, then a 97 GT, then 98... etc. (i think you are going to find more outbacks out there than GT and LSi combined.)

 

there are lots of things to consider price, shipping cost, mileage. some yards sell them all for cheap 300$ while some charge 1200$ for one with 200k miles. but there are lots of them out there. i'd look for a 96 - 98 outback with 100k or less, close to home. since yours is still running (?), you have some time to shop and wait.

 

and finally, before you buy, ask for the model number off of the trans you are buying to double check.

 

 

 

 

I'm confused now. I just bought a transmission from a 96 Legacy AWD 2.5 engine manufactured 09/1995 with the transmission number

TZ102Z2AAA-CG to use as a donor to replace the transmission in my 96 Legacy Outback manufactured in 1996 with transmission number

TZ102Z2ABA-CH. Curiously the Holland interchange software identifies my trans as that of a 2.2L car (which it is not). A quick check with Emily at the good ole guys at CCR out in Denver produced a look-up result from a Subaru reference manual that states that the gear ratio of both of these is 4.44 and the conclusion is that it will work.

 

Now am I good to go or not? What's the verdict? What hasn't been addressed in the quoted data above is a 96 Legacy 2.5 AWD with the trans number TZ102Z2AAA-CG. I sure don't want to put this in if it's not the same ratio as the rear differential.

 

I believe I'll post this on my thread about torque bind too.

Steve

[steamin53]

By the way John your message box is full and can't be posted to.

 

Steve

[2.5GL]

i take it the hub with the grooves worn in it is not easiliy replaceable.

 

If you remove the hub from the trans to grind down the grooves, replacing it is easy at that point... the hardest thing to do is spend the money:lol:

 

Lewis

 

Steve: pics to come, but may take a couple of days due to the holiday weekend, and no electronics for me where I am going:headbang::headbang:.

[steamin53]

If you remove the hub from the trans to grind down the grooves, replacing it is easy at that point... the hardest thing to do is spend the money:lol:

 

Lewis

 

Steve: pics to come, but may take a couple of days due to the holiday weekend, and no electronics for me where I am going:headbang::headbang:.

 

 

John,

 

I need most at this time the answer to the significance of the last three letters in the transmission number; i.e. AAA vs ABA.

 

I'm confused now. I just bought a transmission from a 96 Legacy AWD 2.5 engine manufactured 09/1995 with the transmission number

TZ102Z2AAA-CG to use as a donor to replace the transmission in my 96 Legacy Outback manufactured in 1996 with transmission number

TZ102Z2ABA-CH. Curiously the Hollander interchange software identifies my trans as that of a 2.2L car (which it is not). A quick check with Emily at the good ole guys at CCR out in Denver produced a look-up result from a Subaru reference manual that states that the gear ratio of both of these is 4.44 and the conclusion is that it will work.

 

Now am I good to go or not? What's the verdict? What hasn't been addressed in the quoted data above is a 96 Legacy 2.5 AWD with the trans number TZ102Z2AAA-CG. I sure don't want to put this in if it's not the same ratio as the rear differential.

 

 

I read somewhere on this site that only the first character i.e. A** is of significance and the the other two i.e. *AA or *BA have no meaning as regards the gear ratio of the transaxle. That may explain the Hollander interchange identifying this AAA suffix transmission as a match to my ABA suffix.

I'm just confused about the statement in some of the dialog that indicates that the transmission AAA is from a non-outback legacy and will not sub as an ABA transmission in an outback model (I don't think that's correct but need verification).

 

Steve

 

Steve

[cookie]

I agree with Emily. As long as the electricals and the gear ratio are the same that tranny should fit.

[johnceggleston]

the TZ102Z2AAA is from a 96 2.5L legacy, LSi (or maybe GT, the 97 GT ended in CA not AA but i can't find any record of a CA trans in 96.) and it has the final drive ratio of 4.44. the last AA means legacy.

 

the TZ102Z2ABA is from a 96 outback, it could be 2.5 or 2.2, they used the same trans for both that year, it too has the final drive ratio of 4.44. the last BA means outback. (they also used the BA on some impreza outback trans.)

 

the 2 after the second Z indicates 2.5L which means 4.44 final drive. (one exception: the 96 outback w/ 2.2 used the 2.5L trans as i just mentioned and it also had the 4.44 final drive.)

 

the last 2 charactures (after the "-") in the trans part number mean nothing.

the last 2 charactures before the "-" indicate the model of car, legacy, outback, GT or LSi. these do not limit the interchangability of the trans.

the "2" after the second Z indicate the 2.5L engine which dictates the final drive ratio of 4.44. this does limit the interchange of the trans. (4.44 vs 4.11)

if the characture after the second z is a letter then the engine is a 2.2L and the final drive is 4.11.

 

the 3RD to last characture, just before the BA or AA, indicates the version of the trans, A came before B and C came after. there may be slight differences in these trans models, but there seems to be no difference in the 96 leg wagon trans (...ZABAA) that i put in a 95 leg sedan (...ZAAAA). i think thses simply indicate different production runs or years.

 

this only applys to 95 - 99 phase I automatic transmissions.

 

hope this helps.

[steamin53]

the TZ102Z2AAA is from a 96 2.5L legacy, LSi (or maybe GT, the 97 GT ended in CA not AA but i can't find any record of a CA trans in 96.) and it has the final drive ratio of 4.44. the last AA means legacy.

 

the TZ102Z2ABA is from a 96 outback, it could be 2.5 or 2.2, they used the same trans for both that year, it too has the final drive ratio of 4.44. the last BA means outback. (they also used the BA on some impreza outback trans.)

 

the 2 after the second Z indicates 2.5L which means 4.44 final drive. (one exception: the 96 outback w/ 2.2 used the 2.5L trans as i just mentioned and it also had the 4.44 final drive.)

 

the last 2 charactures (after the "-") in the trans part number mean nothing.

the last 2 charactures before the "-" indicate the model of car, legacy, outback, GT or LSi. these do not limit the interchangability of the trans.

the "2" after the second Z indicate the 2.5L engine which dictates the final drive ratio of 4.44. this does limit the interchange of the trans. (4.44 vs 4.11)

if the characture after the second z is a letter then the engine is a 2.2L and the final drive is 4.11.

 

the 3RD to last characture, just before the BA or AA, indicates the version of the trans, A came before B and C came after. there may be slight differences in these trans models, but there seems to be no difference in the 96 leg wagon trans (...ZABAA) that i put in a 95 leg sedan (...ZAAAA). i think thses simply indicate different production runs or years.

 

this only applys to 95 - 99 phase I automatic transmissions.

 

hope this helps.

 

Thanks John,

 

That's how I understood it and you have confirmed my understanding. It looks like we have a winner.

 

Steve

[2.5GL]

Well, here they are... new pics showing more detail.

 

#1. Rear output driven drum in place. This is how it should look when reassembled.

 

#2. Rear output driven drum being removed.

 

#3. Notice orange teeth inside drum and corresponding grooves on the hub.

 

 

Lewis

[2.5GL]

More of the clutches...

 

#1. Retainer ring holding clutches in the drum.

 

#2. Clutches stacked showing alternating teeth in and out.

 

#3. Clutches spread out showing retainer plate (the one missing every-other tooth) and retainer ring, far right.

 

 

Lewis