This is a '92 Legacy

 

So my rear diff was smoking/tight all of a sudden and I changed the oil. It was running okay for a couple of days(a little vibration/grinding) and now it is smoking and tight again. There are no visible wet leaks, and there was a good amount of oil left when I changed it. I didn't see very much metal in the used oil, but like I said, there has been some grinding. Do I have to replace the unit? Is there just a gasket I could replace? And how much will it cost?

 

Thanks

In my experiences once you can "hear" the differential it is time to replace or rebuild it. I could probably find one locally in the $50 range but who knows wherever you live.

If you're sure it is the rear diff, probably the easiest thing to do is swap in a used one. Of course the gear ratio must match your front diff, but maybe circa '92 they were all the same anyway.

 

For reference, this thread is continuation of the one started here: http://www.ultimatesubaru.org/forum/showthread.php?t=80588

http://bbs.legacycentral.org/viewtopic.php?p=211571&sid=e48c3ef81a2c5bb471b7f9527f7f5096

 

This is the link to the writeup on replacing the rear diff. Remember, you may need an alignment when done, unless suspension stuff is marked before it's removed (rear struts don't matter).

 

EDIT: What a DA I am! I got this confused w/another thread I'm helping on...regardless, here's an interchange chart as it sounds like you'll be replacing your rear diff:

http://bbs.legacycentral.org/viewtopic.php?t=13500&sid=7add370daf15909c801cba58 f69c2cbd

 

This is for USDM models, so not sure how valid it is for you Int'l guys.

That is a nice writeup. I love the use of the duck decoy 'special tool'. Can you get those from snap-on?

when removing the rear diff, does the 'front member' have to come out?

when removing the rear diff, does the 'front member' have to come out?

 

If you're referring to the one holding up the rear of the tranny (not the diff itself), it does not....otherwise, I'm not sure.

when removing the rear diff, does the 'front member' have to come out?

 

I never have???

 

One tip for removing most Subaru Rear diffs. It actually makes it easier if you don't use PB on the rear nuts. This will sometimes cause the nut to turn the stud out of the case. Then you don't need to slide the whole thing forward 2" to clear the studs.

<< Originally Posted by johnceggleston

when removing the rear diff, does the 'front member' have to come out?>>

 

I never have???

 

One tip for removing most Subaru Rear diffs. It actually makes it easier if you don't use PB on the rear nuts. This will sometimes cause the nut to turn the stud out of the case. Then you don't need to slide the whole thing forward 2" to clear the studs.>>

 

me too. i remember a day i went to a u-pull-it and pulled 4 LSD's out. never once touched a "front member"

I have a 3.90 non-lsd rear diff for $50 plus shipping. If your 92 is an auto then it has a 3.90.

In my experiences once you can "hear" the differential it is time to replace or rebuild it. I could probably find one locally in the $50 range but who knows wherever you live.

 

My car has a quiet 'wobba-wobba-wobba' sound when driving over a certain speed. Is failure imminent?

 

- Scott

Probably not. Drain the lube and look for metal if really concerned. I would suspect the tires if old and worn.

My car has a quiet 'wobba-wobba-wobba' sound when driving over a certain speed. Is failure imminent?

 

- Scott

 

probably not, but depends what it is too. could be ball joints or wheel bearings too.

i came across this. i hope it helps, but it may not apply.

 

http://endwrench.com/images/pdfs/RearDiffInfo.pdf

Probably not. Drain the lube and look for metal if really concerned. I would suspect the tires if old and worn.

Metal is not an issue if theres some flakes, bear in mind, these things are designed to wear out slowly, very very slowly, so metal in the oils not a huge concearn, however if you got a disco ball show coming out of your diff, meaning, if you drainit and you start to boogie down, youve got issues, after not draining a diff for a long time, it will be close to that but, you should be able to discearn if theres issues from the metal. If I made any sence what so ever :-\ .

This made my day a bit happier:

"if you got a disco ball show coming out of your diff"

I am still cracking up from that..........

What if draining the gear oil doesn't make you want to boogie down necessarily, but makes you want to wear these shoes?

well, um.... hmm. You may have a problem that I cannot solve. Im only a Mechanical person, not psych.