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boxerhummfetish

Very odd drivetrain/transm. issue with 1st Gen 1993 Legacy 4wd AT

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Okay, I've developed or first noticed some very strange issues in an old 1st Gen Legacy wagon. It's a 1993 Legacy 4WD with Automatic transmission that I bought late spring this year and drove across to the east coast (exciting adventures). Anyways, aside from an incident with more than expected oil consumption (compared to my EJ 1.8 Impreza that burns next to none), I'm just coming up with an issue I'm concerned about.

 

The symptom occurs only sometimes, and is only noticeable at very low idle/walking speeds; it's as if you left on the parking brake on--there is extra resistance force that brakes the car, usually to a halt, from walking speed; you need to tap the throttle where normally idle would move you forward.

 

Then, the other odd thing is, once you're at halt, and you switch it out of gear, say from D to R or P, or from R to P, there is a slight jerk and thud from what might be the transmission; the release of power is noticeable as a jerk which actually moves the car forward by some a few millimeters or slight amount. It's also possible these symptoms occur more frequently when making sharp turns (extreme steering deflections) during parking maneuvres--but maybe I'm imagining this correlation because parking often involves such turns.

 

This is so weird. Does anybody have a clue or guess as to what this may be? TIA

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Do a search for "torque bind". If the fluid in the transmission is never changed, it doesn't let the AWD clutch pack slip normally like it's meant to in a turn. That makes it bind up and act like a 4x4 truck instead of AWD.

 

If your AT Temp or Power light is flashing on the dash 16 times every time you start the car, you have a failed Duty C AWD solenoid in the transmission. If it isn't flashing, then changing the fluid a few times should fix it.

 

There's a 17mm drain plug on the sheetmetal transmission pan, and you fill it through the red handled dipstick on the drivers side of the car. There's also a drain plug on the front differential that's much bigger and goes into cast aluminum, and it's dipstick is a yellow loop handle one on the passenger side of the transmission. Don't try filling the transmission through that one, it takes gear oil instead of ATF. A lot of transmissions have been ruined by people draining the wrong compartment and overfilling the other, so make sure you're doing it right.

 

So drain and refill the transmission pan with Dex/merc ATF (usually 4-5 qts of fluid per change), drive it around for a bit, change the fluid again, drive it some more, and change it again. You can only change a portion of the fluid in the transmission per drain and refill, so changing it 3 times swaps out most of the old oil with fresh.

 

The fresh fluid should stop the binding.

 

Your legacy is also a "New Gen" car, and questions about it should be posted in the New Gen forum, rather than Old Gen.

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I Kindly Suggest to Start with a Complete Flush and AT Fluid Change, and include a Pint of "Trans-Medic" ATF Additive, it should make that Transmission to Shift smoother after the first 100 Miles of Normal Driving with the New AT Fluid + the Said Additive.

 

Good Luck!

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Hey, thanks everybody. I will look into all these possibilities. I did change the ATF fluid before my trip east (one flush only though)--and, like 91Loyale warned, I actually messed up with interchanging the fluids with the front diff, but quickly corrected the mix up. (Sorry 91Loyale for posting in OlderGen; my thought was this old Subie had more in common with the Older Gen drivetrain-wise than New Gen which are now all AWD and not 4WD. )

 

I think I may try the Gunk additive you suggested, I've had a great experience with their Steering rack additive (fixed everything), and if that doesn't work look at the possibility of something wrong with the CV or U joint.

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