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Would towing a 4wd car result in torque binding?


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I purchased a 1992 Legacy automatic that needed a lot of work. It arrived at my shop after being towed on a car dolly rear wheels on the ground drive shaft in place for approx 10 miles. The car reportedly has a freshly rebuilt transmission. On the first test drives Iv noticed a binding when turning sharply. Also there is a noticeable clunk in the rear end that disappears when i put the car in manual mode and drive.

Could the towing have caused this issue with the trans?

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"Needed a lot of work", like what?

 

Verify trans and rear diff are same gear ratio. Have the trans or diff ever been swapped?

 

Install the FWD fuse and see if that mitigates it.

 

The one I saw towed a long distance on a dolly hosed the center differential in the manual transmission. I think most of the issues happen in the center diff/MPT clutch packs because that's where one thing is spinning and another is not, with no fluid circulating either.

 

I doubt the rear diff is the culprit, Subaru rear diff failure is rare. If they do fail due to high loads it's the stubby shafts that shear off which clearly isn't the case here. usually they're replaced only to find that didn't repair the issue.

 

Clunk - check the rear diff or trans mount bushings first.

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Thanks for the feed back.

Whats the best method for confirming the gear ratios are matched?

Ill install the FWD fuse and see if that has an effect.

 

Lots of work.  The car had been sitting for a couple of years with a blown head gasket.  There were some wiring issues that took a minute to sort out.

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Thanks for the feed back.

Whats the best method for confirming the gear ratios are matched?

Ill install the FWD fuse and see if that has an effect.

 

Lots of work. The car had been sitting for a couple of years with a blown head gasket. There were some wiring issues that took a minute to sort out.

1. You should describe the wiring issues - a disconnected/cut Duty C or trans signal will give torque bind.

 

2. Is the trans operating perfectly otherwise?

 

3. If it's only binding when turning then we can nearly guarantee that they're the same. Mismatched will bind even while driving forward. If you've driven a good bit you'll know the answer to that question.

 

4. List any check engine codes.

 

5. Is the AT light flashing 16 times on start up?

 

6. Changing the fluid a few times immediately at the first onset of symptoms is usually very helpful particularly if a car sat for awhile.

 

Granted this one was improperly towed but probably still worth a shot.

 

Theres a good chance the clutches are hosed but want to rule out simple things like fluid changes, wiring, or wrong rear diff.

 

The rear clutches can be rebuilt without dropping the trans so it's not a show stopper. Annoying working under a car but otherwise not a big deal.

 

If the FWD fuse works you can just install a toggle switch to switch between FWD and 4WD, it's really easy.

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The only codes Im getting at this time are 33 speed sensor. The speedometer is not connected.

 

The car drives fine with the exception of tight turns, I can see the rear wheels chirp like a locking diff would.

 

Well The FWD fuse has an effect but not what I was hoping for.  The binding is still there with the rear wheels and the car will not shift out of first gear.  In AWD the car shifts fine.

 

Can I disconnect the rear drive line and continue to use the car as a two wheel drive until a repair can happen.

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Okay - it sounds like it's in the transmission then. Rear clutch pack issues seem more likely.

 

Yes you can run it in FWD with the rear driveshaft removed just fine, assuming everything else is working properly.

Edited by grossgary
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Thanks Grossgary

I assumed my question about removing the drive shaft was so wrong that no one was going to respond. I didnt get your message until I had dissembled and reassembled the rear diff.  Mechanically  everything looked good, However the trans fluid was clean but very contaminated with water.  The car has set outside in the rain forest for more then 2 years. I did a full tear down inspection  and  electrical test of the solenoid. Ill pick up fresh trans fluid tomorrow and see where I'm at.

BTY this is a $350 car

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I flushed the Trans twice... Not enough you can still see water in the drained fluid. It may have helped the binding somewhat its only noticeable when the wheels are at almost full lock. Ill flush it a couple more time with inexpensive fluid.

 

I'm curious as to why the car wont shift out of first gear when I install the FWD fuse?

 

I purchased the car for the motor and wiring harness never expecting to drive it. After replacing the head gasket  I just put the engine back in the car to see how it ran. After becoming aware of the damage the transmission may have been subjected to I'm extremely impressed with its durability.

 

Ill continue to drive it until I'm ready to put the engine in my project car or until the transmission goes south.

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I'm curious as to why the car wont shift out of first gear when I install the FWD fuse?

 

That's not normal - probably because there's still water in it or something ominous....

 

How could a transmission get that much water in it?   The hood was left up and the dipstick removed? 

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I have no Idea,  We do get over 100" of rain a year and it looks like the hood had been removed at one time.  Im guessing form the looks of the folks I purchased the car from,  drugs may have been involved.

Edited by USFS68
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I took the car out for a few hot laps on a wet concrete and gravel closed course and hammered on it pretty hard this produced a howl and an increase in the binding. Back at shop I started to pull things apart when I noticed that the drive shaft carrier had come free and was resting on the exhaust pipe. I suspected  thats what was causing the howl. I put things back together and the Torque binding is gone. The AT light is flashing 16 times at startup and the car still wont shift out of first gear with the FWD fuse installed. I can get it to shift 1st through 3rd in manual FWD.

It is it is shifting perfectly in AWD

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 Mr GreaseMonkey . Which issue are you referring to? I suspect there is a combination of things wrong here. The towing may have caused a problem and also the condition of the ATF fluid and the amount of time the car has been sitting was a contributing factor.  If you mean the carrier bolts coming out? that was me not putting things back together properly before I took the car out. The car not wanting to shift in FWD I don't have a clue I'm hoping I don't need it

 

Ill have an opportunity to drive the car 100 miles tomorrow if anything changes Ill report back.

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