96 Legacy - Rear Diff. Compatibility?

[davewilson]

Hello, I've got a '96 Legacy L Wagon with 210,000 kms and she's running stronger than ever, with the exception of the rear differential. For the past 10,000 kms or so any time the drivetrain is under heavy load (climbing hills, hard acceleration) the rear differential makes a high pitched "squeal" that sounds almost like a whistling sound. It's not a wheel bearing noise as it doesn't change tone when cornering, it's tone only changes depending on how hard you press the gas pedal. There are a few Legacys at my local scrap yard and they let the rear diff. go for $50 so I was thinking I would just try swapping in one from there and seeing if the noise goes away.

So my question is, which models and years of Subaru's will the diff swap straight into my Legacy? Thanks,

Dave.

[mike-tracy]

So an automatic 96 L has 4.11FD gears, manual has 3.9

Both auto and manual 90-94 Legacys (non-turbo) have 4.11FD
Manual 90's imprezas with the 2.2 motor have 3.9FD


If you have the right gear ratio, it should work. Only thing I can think of is you might need the donor car's rear axles

[Legacy777]

The 92-94 non-turbo auto trans legacy has a 3.90 final drive ratio, so does the 91-94 turbo legacy.

There may be some differences between the first gen legacy and your diff. I'd try and find one from a mid 90's impreza or Legacy. You can verify your FD ratio on your car and the cars in the junk yard by looking at the marking. The newer diff's have the marking on the top webbing. Check out page two of this scan.

http://main.experiencetherave.com/subar ... f_info.pdf

[mike-tracy]

The 92-94 non-turbo auto trans legacy has a 3.90 final drive ratio, so does the 91-94 turbo legacy.

There may be some differences between the first gen legacy and your diff. I'd try and find one from a mid 90's impreza or Legacy. You can verify your FD ratio on your car and the cars in the junk yard by looking at the marking. The newer diff's have the marking on the top webbing. Check out page two of this scan.

http://main.experiencetherave.com/subar ... f_info.pdf

If you're right about the N/A's, Josh, I have some editing to do. But the 2 n/a wagon diff's I took apart were 4.11111....'s by counting and dividing the teeth.

[davewilson]

Thanks for all the help! My '96 Legacy is a 2.2 MT. The one junk yard I've checked out by my place has 2 '93 legacy's and 2 '00 impreza's. Going to pull my diff this weekend and have a good look at it before I go back. Going to check around some other local junk yards too. Thanks again for the help!

[Legacy777]

If you're right about the N/A's, Josh, I have some editing to do. But the 2 n/a wagon diff's I took apart were 4.11111....'s by counting and dividing the teeth.

If they're from auto trans cars, they should be 3.9. I've got a buddy who had a 92 wagon and it had a 3.9 final drive.

[davewilson]

Thanks again for the help! Funny thing is... after I wrote this post and read over it before I posted it something just didn't sound right. I've been thinking about it and if it is a worn diff. bearing that is making that high pitched whistling noise (does it ever day at the top end of each gear before I shift to the next) it would make sense that the bearing would have failed or got substantially worse over the past 10,000 kms. I think I'm going to see if I can replicate the noise at a stand still... hopefully it's just a weird exhaust whistle I've got going on.

[davewilson]

Well some parkinglot revving at lunch confirms it... it's not the diff. With the car in neutral it still makes the whistling noise at really high rpm. I can't believe I didn't think to try that before haha. It sounds like it's coming from the front of the car now that the car is at a stand still. Hard to tell though. Going to put the car up on stands this weekend and check the exhaust from the header all the way back for any kind of leaks or damage.

Thanks for the help everyone! I've found this forum really helpful for solving quite a few issues I've had with my legacy!

Oh and here is a link to another forum that helped me confirm that it must be from the exhaust... sounds exactly like what they are describing:
http://www.subaruforester.org/vbulletin ... ndex4.html

[Legacy777]

My Legacy had something similar and so does my Impreza. On the Legacy the problem was a rusting muffler. I'm assuming on the Impreza it's something similar in the exhaust.