Jump to content
Ultimate Subaru Message Board

Recommended Posts

Does anyone know if a Tranny made for '92 Leggie works properly on a '91 Leggie? Right now, I have a '92 Tranny on my '91 and it's acting weird. I posted about it back in '05 about the rear wheels locked when in AWD mode. Works okay in FWD mode. Been driving in FWD mode 90% of the time since then. Lately, though, when I accelerate really hard, the car pulls to the left. It pulls just a little when in FWD mode, but when it's in AWD, it pulls left really hard/bad. Not sure if I should look for a '91 Tranny to replace it or I should just drive it until it breaks. Need some advice...

Link to comment
Share on other sites

They should swap just fine as long as you go with Auto-Auto. As I recall, the 1992 Final drive is 4.111 just like the 1991 final drive is. You just have to make sure you get a transmission that matches the final drive you already have.

 

What does this rear wheels locking up tell you (if anything)? Good thing I also got the TCU made for '92 and replacing the '91 TCU with the '92 version enable me to drive in AWD. With the '91 TCU and in AWD mode, it would completely lock the rear wheels to an undriveable point. It would drive okay in FWD mode with the '91 TCU. So, because of that I've been driving with the '92 TCU installed all this time. However, because of pulling hard to one side, I've been driving in FWD mode about 95% of the time.

Link to comment
Share on other sites

No offense to Manarius....

 

I'm 99% sure the '90 and '91 Legs are 4.11; '92-'94 are 3.9. This is for the 2.2 Non-turbos, Automatic, AWD. I replaced mine in July and had to figure this out and make sure I got the right rear diff.

 

I don't understand how the AWD can work on your car, regardless of the TCU you're using,...that's a mystery. But maybe the pulling to one side is indicative that it's the wrong diff.

 

Here's a link that's a bit hard to follow, but shows the Legacy rear diff history:

http://bbs.legacycentral.org/viewtopic.php?t=13500&sid=7add370daf15909c801cba58f69c2cbd

Link to comment
Share on other sites

No offense to Manarius....

 

I'm 99% sure the '90 and '91 Legs are 4.11; '92-'94 are 3.9. This is for the 2.2 Non-turbos, Automatic, AWD. I replaced mine in July and had to figure this out and make sure I got the right rear diff.

 

I don't understand how the AWD can work on your car, regardless of the TCU you're using,...that's a mystery. But maybe the pulling to one side is indicative that it's the wrong diff.

 

Here's a link that's a bit hard to follow, but shows the Legacy rear diff history:

http://bbs.legacycentral.org/viewtopic.php?t=13500&sid=7add370daf15909c801cba58f69c2cbd

 

No wonder I'm hearing a "emmm...." noise from under/rear of the car now. The noise sounds kind of like engine breaking (in 4x4 Low gear in true 4x4 SUV/Truck going down steep hill). The faster the car travels, the the louder it gets and the noise tends to go a little higher pitch in highway speed. I guess it's time to swap out the rear differential?

 

So, tell me. To correct this problem, what do I need besides the rear differential? Do the rear right and left axles need to be replaced as well? How hard is it to accomplish this?

Link to comment
Share on other sites

So, tell me. To correct this problem, what do I need besides the rear differential? Do the rear right and left axles need to be replaced as well? How hard is it to accomplish this?

 

Only the diff. The axles can stay. There is a great write-up on this - may be on USMB...I just saw it a couple days back, but now can't find it:mad: ....I'll let u know if/when I do.

 

What I remember is you'll need to get the correct punch to remove the inner roll pins, remove the bolts that hold the diff up, disconnect the driveline, and likely have to disconnect some rear suspension pieces to gain enough room to drop the diff out (Note: I didn't try this, but it seems like you should/could be able to put the rear tires up on ramps- not on jacks - and this would allow the rear diff to drop low enough that the axles would come out, since the wheels would be compressed up by the weight of the car vs. hanging in the air if on jacks??? I'm likely missing a key issue w/this idea, otherwise it would be documented that it works!!!:-\ ).

 

None of it was technically challenging, but some of the bolts were way tight - make sure you either have a breaker bar or air tools, and hitting the bolts/nuts w/WD40 or PB Blast the night before could make it go a lot smoother if you have rust to contend with.

 

Good luck!

Link to comment
Share on other sites

Thanks. So that means I will need to find a '92 Auto rear differential. I hope I can make this work without having to buy a '91 tranny, which is a pain to install because of lack of time and a garage. Do you know if this "emmmm...." noise is coming from the rear differential wearing out or something?

Link to comment
Share on other sites

Thanks. So that means I will need to find a '92 Auto rear differential. I hope I can make this work without having to buy a '91 tranny, which is a pain to install because of lack of time and a garage. Do you know if this "emmmm...." noise is coming from the rear differential wearing out or something?

 

 

Actually, you have many choices. If you check that link I gave above, all listed as 3.9 from '91 Turbos to '94 will work for your rear diff. Doesn't have to be an Auto either, I'm pretty sure.

 

I'm not good diagnosing noises...but hopefully it's the rear diff vs. the tranny itself. Does the noise go away w/the FWD fuse in?

Link to comment
Share on other sites

Oops, dupe post...

 

I saw your post on legacyentral, too. I wanted to add you 'may' be OK driving in FWD mode to save $$ on replacing the rear diff, but I've read mixed reviews on doing that. It's supposedly a diagnostic mode, so it may damage your tranny over time...can't say for sure.

Link to comment
Share on other sites

No offense to Manarius....

 

I'm 99% sure the '90 and '91 Legs are 4.11; '92-'94 are 3.9. This is for the 2.2 Non-turbos, Automatic, AWD. I replaced mine in July and had to figure this out and make sure I got the right rear diff.

 

I don't understand how the AWD can work on your car, regardless of the TCU you're using,...that's a mystery. But maybe the pulling to one side is indicative that it's the wrong diff.

 

Here's a link that's a bit hard to follow, but shows the Legacy rear diff history:

http://bbs.legacycentral.org/viewtopic.php?t=13500&sid=7add370daf15909c801cba58f69c2cbd

Meh. My mistake. It's kinda tricky what cars got the 4.111. It's weird because the 90-91 have 4.111 and the 92-94 have 3.9. But, the 1991 Turbo has 3.9 as well.

 

I guess in 95 they went back to 4.111? *shrug*

 

No offense taken. I remember what my 91 had. You could still do the swap though as long as you matched the rear diff.

Link to comment
Share on other sites

Actually, you have many choices. If you check that link I gave above, all listed as 3.9 from '91 Turbos to '94 will work for your rear diff. Doesn't have to be an Auto either, I'm pretty sure.

 

I'm not good diagnosing noises...but hopefully it's the rear diff vs. the tranny itself. Does the noise go away w/the FWD fuse in?

 

No, the noise doesn't go away whether it's in FWD or AWD mode. It's getting louder within the past few weeks or so, too. What I'm hoping for is that only the rear differential is needed and nothing else (assuming nothing breaks while I try to get it off).

Link to comment
Share on other sites

http://bbs.legacycentral.org/viewtopic.php?p=211571&sid=e48c3ef81a2c5bb471b7f95 27f7f5096

 

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).

 

Thanks for the linky. Exactly what I need to know and see when I do mine. :clap:

Link to comment
Share on other sites

Okay, just got back from a wrecking yard and got my a 94 rear diff for the price $95.00. It has a plastic plug at the rear top. I unplugged it and the oil/lubricant inside is clear/clean, looks like it's not a part of the main oil. I wonder what that is for. I unscrewed the drain plug and the lubricant is thick and almost black and very little. Hope the diff is still good. It doesn't have any burnt smell to it, so that's good. Leaving it drain overnight to make sure all the old fluid is gone. Then gonna fill it with AMSoil Full Synthetic Gear Fluid.

 

Will try to put it on next week some time. Hopefully it's not too cold to work on it outside. Or I might have to work on it at my brother's garage. Wish me success. Thanks...

Link to comment
Share on other sites

It sounds like you're saying there are 2 fluid containers in the diff? The 'good' stuff on top; and the not so good on bottom? I'm pretty sure it's all the same, though. Does it turn freely by hand? If so, you're probably fine.

 

Also, I found this on 'endwrench':

http://www.endwrench.com/pdf/drivetrain/GearRatiosInfoF99.pdf

 

I hope yours is still OK.

 

Good luck w/the install.

Link to comment
Share on other sites

It sounds like you're saying there are 2 fluid containers in the diff? The 'good' stuff on top; and the not so good on bottom? I'm pretty sure it's all the same, though. Does it turn freely by hand? If so, you're probably fine.

 

Also, I found this on 'endwrench':

http://www.endwrench.com/pdf/drivetrain/GearRatiosInfoF99.pdf

 

I hope yours is still OK.

 

Good luck w/the install.

 

Funny thing is even after I emptied out the dirty bottom fluid, the top still is full of fluid. This compartment (or whatever you call it) seems to be very small, though, and by itself, not connected to any others.

 

The diff seems to turn smoothly by hand. Is it a good idea to use some kind of flush fluid to try to clean out the dirty fluid that still clings to the gear/teeth of the diff.? I was thinking of pouring a bottle of Engine Flush (those that used before changing oil) into the diff., close the plug, and and shake or spin it. Is there any danger to it? I want to clean it as thorough as possible before putting new fluid in. What do you think?

Link to comment
Share on other sites

You're not supposed to drive in FWD mode. It's only for emergencies. I've been told it will burn up your duty c selonoid.

 

I don't know if someone has mentioned this because I didn't feel like reading the entire thread but I thought I'd let you know.

 

I put a 93 or 94 tranny in my 90 and it was a different ratio tranny so I had to get the rear diff but I didn't change the TCU or anything else and it's ran great for over a year.

Link to comment
Share on other sites

You're not supposed to drive in FWD mode. It's only for emergencies. I've been told it will burn up your duty c selonoid.

 

I don't know if someone has mentioned this because I didn't feel like reading the entire thread but I thought I'd let you know.

 

I put a 93 or 94 tranny in my 90 and it was a different ratio tranny so I had to get the rear diff but I didn't change the TCU or anything else and it's ran great for over a year.

 

Since I still have my original TCU, I may switch back to it or continue to use the 92 TCU. Afterall, the tranny and rear differential are for the 92-94 year anyway...so it may work better for them.

 

As far as FWD is concerned, I've read here many mixed opinions. Some say it won't hurt it. Others say it would. I've been driving it FWD for the past several years without any issue, so it's a toss-up. Once I have the correct ratio rear differential installed, I will take out the fuse to drive in AWD again.

Link to comment
Share on other sites

Funny thing is even after I emptied out the dirty bottom fluid, the top still is full of fluid. This compartment (or whatever you call it) seems to be very small, though, and by itself, not connected to any others.

 

The diff seems to turn smoothly by hand. Is it a good idea to use some kind of flush fluid to try to clean out the dirty fluid that still clings to the gear/teeth of the diff.? I was thinking of pouring a bottle of Engine Flush (those that used before changing oil) into the diff., close the plug, and and shake or spin it. Is there any danger to it? I want to clean it as thorough as possible before putting new fluid in. What do you think?

 

I think I've just reached my 'level of ignorance', as I don't know what to tell you about the fluid on top, nor do I know the best way to clean it out.:confused: Unless someone else chimes in or you 'google it', I'd call a tranny/diff shop and get their recommendation.

Link to comment
Share on other sites

Funny thing is even after I emptied out the dirty bottom fluid, the top still is full of fluid. This compartment (or whatever you call it) seems to be very small, though, and by itself, not connected to any others.

what car did it come out of? manual or a/t? can you post a picture of the differential?

Link to comment
Share on other sites

I shall take a picture of it before installing it. Not sure what vehicle it came from as the people at the junkyard took it off and just sold it to me. I never saw if it was an auto or manual. I know at least it come from a '94 model.

Link to comment
Share on other sites

I shall take a picture of it before installing it. Not sure what vehicle it came from as the people at the junkyard took it off and just sold it to me. I never saw if it was an auto or manual. I know at least it come from a '94 model.

 

you are describing something that i've never heard of. i thought a picture might help. i've never seen a subaru differential with 2 fluids in it. i would double check that it came off a 94 subaru legacy. and if it does not look like a subaru diff, i'd take it back before i went to all the trouble of installing it. they may have made a mistake.

Link to comment
Share on other sites

you are describing something that i've never heard of. i thought a picture might help. i've never seen a subaru differential with 2 fluids in it. i would double check that it came off a 94 subaru legacy. and if it does not look like a subaru diff, i'd take it back before i went to all the trouble of installing it. they may have made a mistake.

 

It looks just like mine plus the additional fill hole at the top with a plastic plug/cover/lid. I just took some pictures but I don't know how to post them here.

 

Edit: Oops, I lied. Here are the pictures...hope they are clear.

 

101407_0840a.jpg

 

101407_0841a.jpg

Link to comment
Share on other sites

Okay, just an update: I managed to finish this project in about six hours. The noise "emm...." continues, however. At least I got the correct diff for the tranny now, so I shouldn't have to worry about driving in FWD mode anymore.

 

It wasn't as hard I thought. I did it without taking off the front member also. Just lowered the exhaust and the thing came tumbling down. This diff also has the top fill-hole/plug.

 

The diff looks like it should still works. I saw no metal shaving in the fluid, almost as clear as when I put it in back in '05. I guess I can make some money off this diff if someone wants it.

 

The AWD drives much better now. Thanks all!

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...