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Gl wagon rear differential damaged.


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1988 Subaru Gl Wagon.

 

What can be done about a damaged rear differential in case it cant be repaired, because where I live parts are almost non existent. Previous owner drived the car low on diff fluid, when I bought it I had "intermitent" binding on straight lines. Even after replacing the fluid.

 

The problem was gone when I removed the rear driveshaft and the car move freely now, can I drive like this temporarily? The car has a bearing in the middle connecting the two driveshafts.

 

Can I swap the rear differential with one from a newer subaru? Like a legacy?

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When the car Is not in 4WD there is no load in the driveshaft. Sane as when you remove it. Driving with it removed won't hurt it.

 

If the car is in 4WD on dry pavement and the tires are not all the same size, brand model and miles, it will bind up, even going straight.

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Yea, I'm confused. Removing the driveshaft doesn't prevent the diff from spinning.

 

Are you driving it in 4WD on the pavement?

 

 

The bearings in the rear diff are not unique to old gen cars, they still use the same ones in most Subarus up to the current models. So if it needs bearings that shouldn't be a problem wherever you are. The only thing unique about the old gen diffs is the way the axles attach, so the carrier and spider gears need to be reused, but unless it was seriously abused, those likely are fine.

 

Still might make more sense to get a used one shipped to you from somewhere, these are not known to fail under normal use, so I'm sure a decent used one is out there that you can get your hands on.

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You need better diagnosis.

 

What exactly was run low on fluid and how do you know for “certain” it was the rear diff? Just based on previous owners words? Those are usually worth about 62 cents, convince us otherwise! Lol

 

It’s probably torque bind, or mismatched trans and rear diff final drive ratio.

 

If it is the diff just get one shipped they don’t fail enough to make them worth much so if you are desperately short on local parts just pay up and have one shipped. I’ve got them, yards have them, others on here have them.

 

And ideally you keep a complete set of retainers, guys and case so the gear mesh is all retained. Otherwise ask for a complete set of used guts and try and set it up yourself.

 

It’s eiter a 3.7 or a 3.9 final drive.

Edited by idosubaru
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Yea, I'm confused. Removing the driveshaft doesn't prevent the diff from spinning.

 

Are you driving it in 4WD on the pavement?

 

 

The bearings in the rear diff are not unique to old gen cars, they still use the same ones in most Subarus up to the current models. So if it needs bearings that shouldn't be a problem wherever you are. The only thing unique about the old gen diffs is the way the axles attach, so the carrier and spider gears need to be reused, but unless it was seriously abused, those likely are fine.

 

Still might make more sense to get a used one shipped to you from somewhere, these are not known to fail under normal use, so I'm sure a decent used one is out there that you can get your hands on.

 

The car has only two 4WD settings, the lever only moves up and down so I am Asuming 4WD HI and Low, so yeah the car is always on 4WD.

 

Its find hard to explain what the car was doing exactly, it feels like the wheels on the back started to lock/unlock/drag when going faster than 20-30mph, and the car felt slugish, limping. Last time I moved the car, the manual gear shifter locked and I was unable to change gears, so I got the car on jackstands, started it and the gear shifter unlocked. That's when I removed the rear driveshaft, lowered the car, drove around with no issues.

 

 

You need better diagnosis.

 

What exactly was run low on fluid and how do you know for “certain” it was the rear diff? Just based on previous owners words? Those are usually worth about 62 cents, convince us otherwise! Lol

 

It’s probably torque bind, or mismatched trans and rear diff final drive ratio.

 

If it is the diff just get one shipped they don’t fail enough to make them worth much so if you are desperately short on local parts just pay up and have one shipped. I’ve got them, yards have them, others on here have them.

 

And ideally you keep a complete set of retainers, guys and case so the gear mesh is all retained. Otherwise ask for a complete set of used guts and try and set it up yourself.

 

It’s eiter a 3.7 or a 3.9 final drive.

 

I know, but where I live most mechanics don't want to touch Subarus, they are always saying, "Oh man Subarus are so weird" "Its hard to work on them" , even junkyards don't have any. Managed to found one Wagon similar to mine in a God forgotten Junkyard, but theres nothing left in it, aside from body and interior.

 

Back to the post, the rear diff was very low on fluid and I found some metal particles on the magnet, not a lot but enought to worry.

 

I will try to find a good mechanic and report back! This is my first Subaru and I am trying to get as much feedback as I can, so thank you very much everyone for your patience.

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This model Subaru definitely has a front wheel drive only mode.  It is not only 4WD hi or low.  I am not familiar with the particular transmission you have, as all of mine are automatics, but I know that Subarus in this model / age and before  have selectable front wheel drive / 4WD.  [Or 2WD only]   The select on the fly is what made them famous. 

 

The binding and stuck shifter exactly describe what happens on dry pavement.in 4WD,  with mismatched tires or turning.  The only way you can roll in 4WD on dry pavement without binding is 4 brand new tires, and in a straight line.

 

Going by what I've read in this thread, your diff is not bad, unless it is making noise.

Edited by DaveT
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Could the little rubber mount for shift lever plates behind trans be broken? Not allowing 4wd lever to go all the way back into 2wd?

 

88wagon, the mount is bolted to top of driveshaft tunnel underneath just behind the trans. Make sure none of the linkages are loose, bushings all tight too.

Edited by czny
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At this point I am not sure anymore lol, transmission is manual with a lever selector with no decal or way to tell if its in FWD, 4WD Hi or Low, I will install the driveshaft tomorrow morning, lift the car again and check that lever, because as I said before, It seems to move only up and down in two steps, middle does nothing, the car just revs. I dont know if the car was originally an automatic or what because the there´s PRND on the dashboard and what seems like a selector switch (electrical) hidden in the center console, so maybe the dash was swapped, or the trans. 


Found this pic online, my car looks like that.
40032451055_original.jpg

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Could the little rubber mount for shift lever plates behind trans be broken? Not allowing 4wd lever to go all the way back into 2wd?

 

88wagon, the mount is bolted to top of driveshaft tunnel underneath just behind the trans. Make sure none of the linkages are loose, bushings all tight too.

 

I will check that tomorrow, thanks, but I did a little test, I disconnected the steel rod that connects the lever with the selector on the transmission. Moved the selector by hand on the transmission housing and it seems to move only back, middle and up, same as with the lever connected.

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Leave that lever all the way back for 2wd on the street. No 4wd Hi or Lo lights in dash cluster should be lit.

 

Ok, I will do that, maybe the problems it´s just something simple, I will reinstall the driveshaft, left the car in the garage until I can get some fresh tires and hope for the best. My tires are the same brand and all, but maybe they are old, maybe they are deformed In some way and they are causing me trouble.

 

Here´s a timeline maybe it could help.

 

Got the car from the previous owner, drove 20 miles on highway with no issues, then I drove a little bit on dirt with the lever in the top position (Im assuming 4wd Hi because the car felt more "revvy"), then I put the lever all the way back again, drove something like 300 meters straight  and the car began to do that binding/skipping thing that I described, I drove very slowly another 300 meters, pulled over, put the car in reverse, then in first gear and the problem was gone again.

 

Next day I drove around normally, put some air in the tires so they where the same PSI, changed the rear diff oil, and on my way back home from my parents home, on the same straight road the car began to do the same thing as before, this time it did not go away. So again I drove very slowly to my house and when I was parking my gear shifter locked, thats when I put the car on jackstands and released the shifter. Maybe when I removed the driveshaft the rear diff unbinded.

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Sounds like it’s binding.

 

If there’s an automatic dash then maybe it was swapped.

 

If true then there’s a really good chance the front and rear gear ratios don’t match.

 

That will cause binding while driving straight which will go away if you’re in 2wd or you remove the shaft.

 

My guess is the rear and front diff ratios are different.

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Sounds like it’s binding.

 

If there’s an automatic dash then maybe it was swapped.

 

If true then there’s a really good chance the front and rear gear ratios don’t match.

 

That will cause binding while driving straight which will go away if you’re in 2wd or you remove the shaft.

 

My guess is the rear and front diff ratios are different.

 

I'll check that too, rear diff has a sticker that says 3.9, I'm going to look for something similar in the front.

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It very well could be sticking in 4wd sometimes getting back in to 2wd is very hard its comon on selectable 4wd trucks to fix that drive backwards till you can drop the lever all the way down or you could have a full time 4wd 3.7:1 ratio trans out of a turbo but that would have the problem all the time seeing as how it was fine till you used 4wd im guessing its just stuck ive had to go backwards almost a 1/4 mile before to get it to go back in to 2wd driving forward and back as fast as you can can sometimes pop it loose you want to jolt the gears loose and it should shift it sounds like a standerd stuck tcase too me

Edited by ferp420
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The gauge cluster is not an a plug and play swap, so pretty safe to assume that's original, and the transmission has been converted.

 

Virtually all dual-range transmissions (which yours clearly is) are part-time 4WD, and have a FWD mode. Here's the shift pattern sticker that you're probably missing. That "revvy" setting you're feeling is low range:

classic-rust-free-1987-subaru-gl-4wd-wag

 

But those were also all 3.9:1 axle ratio. That interior/shifter is correct for an '88 part-time 4WD dual range, but since it's been swapped, we can't assume that it all came from the same car. We will also have to assume that any indicator lights don't work.

 

There's a chance that you have a dual range full-time 4WD transmission from a Subaru RX turbo in there. That would not have a FWD setting, and it would have a 3.7 axle ratio. There would be a vacuum canister on the LH side of the transmission, connected to a cable on the RH side of the transmission that locks the center diff. I don't think this is likely, because it sounds like you're not getting very severe binding, and when I hooked part-time 4WD linkage to an RX transmission, it was too short and hit the gear stick in 2nd low range and I had to lengthen the rod (although it's not impossible that that's been done here, too).

 

 

 

Ultimately, I think the first step is to look for the transmission code. It should be on a sticker on the transmission bellhousing near the starter. Probably starts with a "TY". If it has that, we should be able to figure out exactly what transmission it is, and then hopefully narrow down what the problem is.

 

 

 

FYI, transmissions and rear diffs have magnetic drain plugs because metal shavings are normal. That's not a death sentence.

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The gauge cluster is not an a plug and play swap, so pretty safe to assume that's original, and the transmission has been converted.

 

Virtually all dual-range transmissions (which yours clearly is) are part-time 4WD, and have a FWD mode. Here's the shift pattern sticker that you're probably missing. That "revvy" setting you're feeling is low range:

classic-rust-free-1987-subaru-gl-4wd-wag

 

But those were also all 3.9:1 axle ratio. That interior/shifter is correct for an '88 part-time 4WD dual range, but since it's been swapped, we can't assume that it all came from the same car. We will also have to assume that any indicator lights don't work.

 

There's a chance that you have a dual range full-time 4WD transmission from a Subaru RX turbo in there. That would not have a FWD setting, and it would have a 3.7 axle ratio. There would be a vacuum canister on the LH side of the transmission, connected to a cable on the RH side of the transmission that locks the center diff. I don't think this is likely, because it sounds like you're not getting very severe binding, and when I hooked part-time 4WD linkage to an RX transmission, it was too short and hit the gear stick in 2nd low range and I had to lengthen the rod (although it's not impossible that that's been done here, too).

 

 

 

Ultimately, I think the first step is to look for the transmission code. It should be on a sticker on the transmission bellhousing near the starter. Probably starts with a "TY". If it has that, we should be able to figure out exactly what transmission it is, and then hopefully narrow down what the problem is.

 

 

 

FYI, transmissions and rear diffs have magnetic drain plugs because metal shavings are normal. That's not a death sentence.

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T-cases get stuck in 4wd all the time http://www.ultimatesubaru.org/forum/topic/19523-87-gl-wagon-stuck-in-4wd/

And http://www.ultimatesubaru.org/forum/topic/20307-91-loyale-problem-agiain/ and

http://www.ultimatesubaru.org/forum/topic/115427-90-loyale-stuck-in-4wd/  and http://www.ultimatesubaru.org/forum/topic/51922-1991-loyale-5sp-stuck-in-4wd-help/ Just a few threads from this board if you google stuck t-case you will get threads about fords chevys internationals jeeps almost every t-case has this issue

Edited by ferp420
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  • 2 weeks later...

Ok, here is the update:

I replaced the transmission seal, Autozone Part number 3771  (5 Speed Manual Transmission TY75F), -So TY75F is the transmission model?
I also found a golden sticker near the starter that reads "049029" so maybe thats the transmission SN.

Anyway, put a set of new tires all around, replaced the transmission seal because it was leaking, reinstalled the driveshaft, and added new fluid to the gearbox.
Drove around a few miles with no apparent issues regarding binding. When I was at my garage I stopped the car and do some testing with the 4wd lever, now it seems that it is engaging at three points, bottom, middle and up, when I let up the clutch the car moved forward on all three settings, before it was only engaging at the bottom and on the top. 

So those two 4WD settings are only for off road, am I correct? 






 

Con transmisión manual de 5 velocidades
Con transmisión TY75F
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Great to hear you now have three positions.

 

Fully down is fwd for dry tarmac or dry concrete only. Low speed driving on dirt is OK under 20 miles per hour only though. Instructions also say to use clutch to shift to 4wd high which is next position up. To pull lever up one more positive feel position is 4wd

low range . Be mindful you can get a neutral in this 4wd selector between hi and low.

Highest up is lowest range.

Well done.where are you so isolated?

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