legacycentral bbs

Hey all, I recently purchased a 93 Legacy AWD LSi wagon with 170K on it. It exhibits all the symptoms of torque bind and in addition it has another issue. Sometimes when placed in Park it will roll back when the engine is turned off. I have no owners manual or maintenance records but the car appears to have been pretty well maintained by a subaru dealer. The last oil change was at the dealer and it even has a Subaru battery. I've searched and come up with various possible fixes such as:

1) Add some LSD fricition modifying additive or Lubegaurd
2) Flush trans and refill with fresh ATF
3) Rebuild the "PTO" rear section of the trans

It seems that if the ATF is worn out that #1 may help temporarily by restoring the friction modifiers that are worn out. #2 seems like the better option except that sometimes flushing a worn out tranny can accelerate it's failure. #3 is expensive and my last resort.

I'd appreciate any advice from those who have had similar AWD AT issues. Thanks in advance.

* I forgot to mention that I have 4 new matching tires inflated to 32 front/30 rear. Also the ABS light has come on a few times. ATF is at correct level and color and smell are good.

Sounds like you've got the right idea. I'd suggest sticking a fuse in the FWD plug in the engine bay on the firewall and see if your problem goes away (just to confirm that's your issue not as a fix).

n2x4 wrote:Sounds like you've got the right idea. I'd suggest sticking a fuse in the FWD plug in the engine bay on the firewall and see if your problem goes away (just to confirm that's your issue not as a fix).

Thanks. I put a fuse in the FWD plug and all the torque bind symptoms are gone as well as the "torque release" symptom when shutting off the engine after stopping. Unless someone has better advice I plan to add 4oz of GM LSD additive to get me thru the winter and then do a complete ATF change using the DIY flush method when weather permits.

I don't know if you're familiar with this DIY flush method but it works great. Drain the pan, drop the pan, change the filter or clean the screen, re-install the pan, re-fill tans. Remove the ATF cooler return line and route it into an empty container. Start the engine and pump out 2 qts, stop and add 2 qts new ATF and so on until the new ATF starts coming out. I exchanged 9 qts from my Scion this way and it doesn't have any of the negative effects of a power back-flush. It seems to work well too as it is very evident when the new ATF began filling the container. It's a PITA but let's you change all the ATF at once .

The only remaining item is the ABS light still comes on frequently.

Check the codes for the ABS system and see where your fault lies. Taken from another thread:

Legacy777 wrote: I'd try pulling the ABS codes to see what is stored and causing the light to go on.

http://main.experiencetherave.com/subar ... bsdiag.jpg

This one shows the connector, but the codes aren't correct for the first gen legacy
http://main.experiencetherave.com/subar ... ostics.pdf

I did the repair on my '90 Legacy from THIS USMB THREAD and THIS THREAD.


Sounds like your rear clutch packs/parking pawl are worn/damaged.


Did you check the ABS tone rings for damage/dirt/etc?


Edit: From my reading there is no filter/screen to clean, but if your pan is dented it may be worth a look.
GL,
TD

Thanks guys! I'll try pulling the ABS codes the next time it appears. For now I siphoned out some brake fluid because the resevoir was over-filled by PO but it's too early to tell if this was causing the ABS light. I'll also check the ABS sensors for dirt and damage. I put 4oz of GM LSD additive into the trans, drove it 10 miles and pulled the FWD fuse. I didn't notice any change in the torque binding. I tried making tight figure 8s in a PL to break the clutches free but no luck. Maybe it will improve with more miles or maybe not. I probably need to rebuild the awd trans extension assy.

Is it okay to drive for extended periods with the FWD fuse installed? I'd like to wait until Spring to do any major repairs. I'd like to drive in FWD mode and only use AWD when necessary. I also looked up AT filters and apparently post 9/91 Legacys have a filter inside the pan. Beck Arnley has a good photo showing the filter media (not a screen).

EDIT: Okay, after a few dozen more miles the LSD friction modifier seems to be helping with the TB. It's too early to start singing praises but it seems to have helped a little. Maybe with any luck my AWD clutches are only binding and not already welded together.

It's now been several weeks since I added 4oz of GM LSD additive to my 4EAT and I have concluded that it made no discernible difference in the torque bind. Any improvement I noted before was due to trans temp which affects the amount of TB felt (less cold, more hot).

Next up will be a ATF change. If that doesn't help I suppose I'll have to replace the transfer clutches, etc. The duty C seems to be working fine. With the fwd fuse installed there isn't even a hint of any TB. With the fuse removed, the TB is pretty bad.

The ABS light stopped coming on so at least that problem can wait.

I finally got around to changing ATF. I simply drained 5qts and added 4qts of fresh ATF and 15oz of Trans-X additive. All previous torque bind symptoms are gone. Whether the improvement was due to the fresh ATF, Trans-X, the trans being slightly over-filled by the PO or a combination of these things is unknown but the results are very satisfying. I can now do tight figure 8s in fwd or rev with no binding. WOOT!