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90 Legacy with 93 drivetrain now torquebind


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I had a 93 legacy that I totaled. The engine and tranny were fine so I bought a 90 wagon and had mechanic made the swap. Both automatics. He replaced the diffs and everything that didn't match, but kept the ECU, TCU and wiring from the 90. At first, it was all fine, but then I started noticing torquebind. I took it back to the mechanic and he replaced the center diff and duty C sol. The problem persisted so he put the old parts in. Tires are fine, and even with the FWD fuse the problem is still there. I think it's either the output from the TCU or the wire to the Duty c. Am I right? Are we missing something in this kind of transplant?

 

Also, in the 90, I had to install the emergency break lever. I took it from the 93. I realized that the wiring is different in both models. Where the 90 uses two wires, one for power and another one for ground, the 93 uses the body as ground. Could this be related to the issue?

 

Also, how exaclty does the duty c work? is it open when powered or closed?

 

I know there is plenty of info on TB, but nothing on transplants. PLEASE HELP! :(

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he replaced the center diff? do you mean rear diff or transfer clutches? auto's don't have a center diff.

 

does it go away with the FWD fuse in?

the front and rear are positively the same ratio?

 

Sorry...He replaced the transfer clutches and the duty c. The problem does not go away with the fuse. The FWD light comes on but the binding still happens.

 

The front and rear were transfered from the 93 to this one. The TB was not there right after I got the car back from the mechanic the first time, and when it started happening, it didn't do it all the time. I assume if the binding was due to the diffs, I would have noticed it before and it would have been permanent from the start. Am I right?

 

Do you know if the wiring in these two models is exactly the same? The mechanic told me it is, but I am not sure. :(

 

Thanks for the help.

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The wiring between the 90 & 93 are not the same. The 90-91 MY's are the same, and the 92-94's are the same.

 

The engine electrical harness is different between the 90-91's and 92-94's, so I'm wondering what he did about that. He could have just swapped the 90 engine harness over to 93 engine, and that should have worked. Other thing to note is the injectors are different in the 90-91's and 92-94's. You should match the injectors with the ECU, so I'd recommend running the 93 ECU. That may lead to issues with the MT/AT identifier. For some reason the 92's onward are wired backwards from the 90-91's and what the factory manual states.

 

I'd suggest reading this info from my swap write-up about the MT/AT identifier

http://www.surrealmirage.com/subaru/swap/electrical.html#ecu

 

If the binding is still there with the FWD fuse in, I'd suggest testing the duty c solenoid

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/duty_solenoid_c_diag1.jpg

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/duty_solenoid_c_diag2.jpg

 

If that checks out ok, then you've got some other sort of issue.

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The wiring between the 90 & 93 are not the same. The 90-91 MY's are the same, and the 92-94's are the same.

 

The engine electrical harness is different between the 90-91's and 92-94's, so I'm wondering what he did about that. He could have just swapped the 90 engine harness over to 93 engine, and that should have worked. Other thing to note is the injectors are different in the 90-91's and 92-94's. You should match the injectors with the ECU, so I'd recommend running the 93 ECU. That may lead to issues with the MT/AT identifier. For some reason the 92's onward are wired backwards from the 90-91's and what the factory manual states.

 

I'd suggest reading this info from my swap write-up about the MT/AT identifier

http://www.surrealmirage.com/subaru/swap/electrical.html#ecu

 

If the binding is still there with the FWD fuse in, I'd suggest testing the duty c solenoid

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/duty_solenoid_c_diag1.jpg

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/duty_solenoid_c_diag2.jpg

 

If that checks out ok, then you've got some other sort of issue.

 

Thanks for the info. I knew there had to be some kind of difference!

I'm not sure, but I think he kept the harness from the 90, the TCU, and the ECU. The engine and tranny are from the 93. I will ask hi about the harness tomorrow.

 

In any case, I picked it up today and the binding was still there. However, I stopped by Les Schwab to check the tire pressure and when I started the car again, there was no POWER llight flashing and there was no binding as I left the parking lot. The car drove great back home. Nevertheless, when I got back home, I drove over some gravel to test it and there it was. It was binding again, and it lurched forwards as I put it in park and stopped the engine. Why is it intermittent like that???

 

Any other ideas or info you can give me I would really appreciate.

 

You guys are great! Thanks :)

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i have lots of questions about this. Just swapping the then new parts back with the old is not the easiest thing in the world to do.

If he didnt know what he was looking at it is very possible that the replacement parts were on thier way out to begin with. ALso they may look the same, but i dont know if the clutch pack from the two trannies are the same.

A majority of the problem may be the mixing of the parts from one generation to another.

How exaclty did he "replace" the parts the first time, were they new?

 

There is nothing on transplants, since this isnt a transplant, this is a frankenstein sadly.

 

The AWD unit is made up of the clutches, the solenoid and an internal pilot valve. WHen the solenoid is energized it dumps the pressure and no awd. The solenoid cycles on and off, and the amount of time between on and off regulates how much awd you get. 90/10 through to 50/50.

 

you can also get AWD at wide open throttle, reverse, and low gear.

 

nipper

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i have lots of questions about this. Just swapping the then new parts back with the old is not the easiest thing in the world to do.

If he didnt know what he was looking at it is very possible that the replacement parts were on thier way out to begin with. ALso they may look the same, but i dont know if the clutch pack from the two trannies are the same.

A majority of the problem may be the mixing of the parts from one generation to another.

How exaclty did he "replace" the parts the first time, were they new?

 

There is nothing on transplants, since this isnt a transplant, this is a frankenstein sadly.

 

The AWD unit is made up of the clutches, the solenoid and an internal pilot valve. WHen the solenoid is energized it dumps the pressure and no awd. The solenoid cycles on and off, and the amount of time between on and off regulates how much awd you get. 90/10 through to 50/50.

 

you can also get AWD at wide open throttle, reverse, and low gear.

 

 

nipper

 

Thank you. The mechanic ordered a new set of clutches for the 93 tranny. They were new from Subaru. He put them in, including the new duty c, but the problem was still there. Now, he might have forgotten and ordered clutches for the 90 since the body is from a 90. Let me clarify that the engine and tranny were from my 93 legacy and I put them into a 90 legacy.

 

He did keep the computers and wiring that came with the 90 and hooked them up to the 93 drive train. This might be the root of the problem. I will take it to another mechanic tomorrow. Perhaps a fresh pair of eyes will spot the issue easily. If he does, I'll let you all know. :)

 

 

So in this case, since the car is in constant 50/50, does it mean that the duty c is not being energized?

 

Thanks again.

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Thank you. The mechanic ordered a new set of clutches for the 93 tranny. They were new from Subaru. He put them in, including the new duty c, but the problem was still there. Now, he might have forgotten and ordered clutches for the 90 since the body is from a 90. Let me clarify that the engine and tranny were from my 93 legacy and I put them into a 90 legacy.

 

He did keep the computers and wiring that came with the 90 and hooked them up to the 93 drive train. This might be the root of the problem. I will take it to another mechanic tomorrow. Perhaps a fresh pair of eyes will spot the issue easily. If he does, I'll let you all know. :)

 

 

So in this case, since the car is in constant 50/50, does it mean that the duty c is not being energized?

 

Thanks again.

 

Yes correct, but i really think the issue here is this 90 on a 93 wiring. and the tcu. Now do u see a power light flash when you turn the car on?

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yes 50/50 means the clutch pack is not doing it's job, either the duty c or the clutch itself is bad. but since the clutch pack was replaced ..... i would ask...

 

how long did you drive the car after the tyranny swap before the binding occurred ? is there any chance that the binding was there and you just didn't notice it. perhaps you were so excioted about your "new car" you weren't being very attentive?

 

some one here has a great thread about the wiring being different on his tranny swap and he had binding. his duty c was not getting the power it needed. i asume that the connector looked the same , but if they moved the wires you may not be powering the duty c solenoid.

 

i can't believe that the new parts have failed already. if they have there is anopther problem or a problem mechanic. just my opinion.

 

 

 

Thank you. The mechanic ordered a new set of clutches for the 93 tranny. They were new from Subaru. He put them in, including the new duty c, but the problem was still there. Now, he might have forgotten and ordered clutches for the 90 since the body is from a 90. Let me clarify that the engine and tranny were from my 93 legacy and I put them into a 90 legacy.

 

He did keep the computers and wiring that came with the 90 and hooked them up to the 93 drive train. This might be the root of the problem. I will take it to another mechanic tomorrow. Perhaps a fresh pair of eyes will spot the issue easily. If he does, I'll let you all know. :)

 

 

So in this case, since the car is in constant 50/50, does it mean that the duty c is not being energized?

 

Thanks again.

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DId he replace the housing also?

 

nipper

 

 

Guys,

 

I am going to try to answer all your questions here:

 

1. The car did not have binding when I got it. I am paranoid about cars and at the smallest alert, sign or noise I have it checked. There was no flashing POWER light or binding at all.

 

2. The mechanic replaced the parts, but since it didn't fix the problem, he put the old ones back in and didn't charge me the $700. He showed me the new parts he ordered from Subaru and we compared them to the old ones. There was no significant difference with respect to wear. That's why he put them back in.

 

3. The car currently has 1993 engine and tranny running on 90 wiring.

 

4. 8 out of 10 times I start the car, there is a flashing POWER light. It flashes 16 times. When I check the code using self-diagnostic mode, I get trouble code 24: duty c. The rest of the times, it starts and drives like a dream for a while and then it binds again.

 

5. He did replace the housing at one time, but it didn't help.

 

Since when I got the car there was no binding, and now it does it most of the time but NOT all the time, I am pretty certain it is an ELECTRICAL ISSUE. Today, I turned the ignition on and put the FWD fuse in. I was able to hear something moving when I put it in and took it out. Is this supposed to happen?

 

Can anybody tell me where to find the connectors that go directly to the duty c?

 

Thank you all or the info. :)

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Guys,

 

I am going to try to answer all your questions here:

 

1. The car did not have binding when I got it. I am paranoid about cars and at the smallest alert, sign or noise I have it checked. There was no flashing POWER light or binding at all.

 

2. The mechanic replaced the parts, but since it didn't fix the problem, he put the old ones back in and didn't charge me the $700. He showed me the new parts he ordered from Subaru and we compared them to the old ones. There was no significant difference with respect to wear. That's why he put them back in.

 

3. The car currently has 1993 engine and tranny running on 90 wiring.

 

4. 8 out of 10 times I start the car, there is a flashing POWER light. It flashes 16 times. When I check the code using self-diagnostic mode, I get trouble code 24: duty c. The rest of the times, it starts and drives like a dream for a while and then it binds again.

 

5. He did replace the housing at one time, but it didn't help.

 

Since when I got the car there was no binding, and now it does it most of the time but NOT all the time, I am pretty certain it is an ELECTRICAL ISSUE. Today, I turned the ignition on and put the FWD fuse in. I was able to hear something moving when I put it in and took it out. Is this supposed to happen?

 

Can anybody tell me where to find the connectors that go directly to the duty c?

 

Thank you all or the info. :)

 

Your duty c solenoid is sticking or dying, if he put the old one back in.

The light flashes to tell you something went wrong on the last time you drove the car.

 

 

i'm sure somone will tell you, if not email me and i have some manuals i can email you

 

nipper

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You need to find out exactly what he did with ALL the wiring for the swap. Do that before you do anything.

 

You really need to be running at least the 93 ECU, and probably wouldn't hurt to run the 93 TCU. Keep in mind my comments regarding the MT/AT identifier pin.

 

 

Thanks. I'm pretty sure he kept the harness, TCU and ECU from the 90. If I get a new TCU (1993), do I need to also get a 1993 wiring harness?

 

The tranny shifts perfectly and smoothly. Besides the TB, there is not other problem with it. If the problem was the computers or the wiring, why would it just affect the operation of the duty c and not the shifting and other things?

 

Also, I read the info on the MT/AT identifier pin, but I'm not sure how this pin could affect me since both cars, the 1993 and the 1990 have AT.

 

Thanks again.

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The ECU & TCU should have the same plugs. You should be able to just swap them.

 

I'm not really sure why it would just affect the duty c solenoid. The main reason I am recommending swapping the ECU is because of the injectors. The injectors styles are different, and the ECU is setup for the individual injector types.

 

The reason the MT/AT identifier pin will affect you is because for some reason the 92+ ECU's are wired backwards for the MT/AT identifer pin, when compared to the 90-91's. For example, if the wiring harness grounds that pin to tell the ECU it's an auto....and you stick the other ECU in, it will be backwards, and the ECU will think it's a manual.

 

NOTE: I know for a fact the 92 ECU is like this and am assuming the 93 is the same. I think it'd probably be best to just hook things up, and see how it runs, if it's acting oddly, then you'll need to deal with the mt/at identifier pin.

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I have absolutly no clue about what the problem is with this monster, since parts have been mixed and matched. This may be un resolvable.

Are we sure the two gear ratios match front and rear? i'm sort of goping with the idea that the doner tranny was sick to begin with.

 

nipper

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