so ya, haven't seen this topic out yet since the reset.

now my issue/questions.


Bought a 1987 Corolla GT-s not to long ago.
guy mentioned not knowing what kind of diff it had. when i looked under the car a few weeks ago,
i saw the good ole "only LSD" fluid sticker on my rear end, gave me some relief as i changed out the diff fluid to check for ring and pinion shaving (found none! to bad i already bought a spare). not only that but my friend mentioned not being able to see spider gears through the holes, only the housing. plus my chassis code and stuff indicated that my car was equipped with one from the factory. awesome day.

fast forward to today when i lifted up the rear to do the test after watching it on YouTube, and i think i got bad news.
spun right tire forward, left tire spun in the opposite direction. from those videos it suggests that i have an open differential, right? seems like there's a bit of play in the wheel while spinning before the opposite side engages.

so does that mean anything? a rebuild set for my near future? swapped internals maybe? im i stuck with this diff?
and if it is open, any suggestions on aftermarket? ive heard of kaaz and trd and cusco, but i didn't wanna kill the bank account hahaha

Your factory LSD is likely worn out. I'd say get a rebuild kit for your spare (3T has one that should get you in better-than-stock condition), swap it in and sell your worn out one.

Any other opinions or answers?
The main thing that killed it for me was the fact that it acted like an open differential by spinning the opposite way the other wheel was.


And even if it was worn. I'd have to buy a new clutch kit right?

Tora makes a great recommendation.
I may be wrong on this but, it has been my experience that the 3 types of diffs act like this;
1) open diff -- spin one tire the other sits still or giggles a little.
2) lsd --- spin one tire the other goes in the opposite direction.
3) full posi/welded --- spin one the other goes in the same direction.
of course this is with the wheels off the ground.
If anyone knows, not suspects, otherwise, please correct me.
I would rebuild the one and install it. Then rebuild the other and keep it for a rainy day.
Good luck!

^Open diff = wheels spin in opposite direction

LSD/welded = wheels spin in the same direction

rebuild one, rock it while you save for a kaaz.

Deuce Cam wrote:^Open diff = wheels spin in opposite direction

LSD/welded = wheels spin in the same direction

That is what is causing my confusion. My rear still has that sticker on it saying it needs LSD fluid. But does a worn LSD act in the matter that mine is?

A worn lsd will act like an open diff. Since these cars are 25 years old it's also possible that a previous owner swapped the 3rd member/pumpkin.

https://technotoytuning.com/toyota/ae86 ... 86-corolla

That's exactly what I'm doing with my differential (if I ever get my hands on a kouki donor to rebuild).

Jacare wrote:

Deuce Cam wrote:^Open diff = wheels spin in opposite direction

LSD/welded = wheels spin in the same direction

That is what is causing my confusion. My rear still has that sticker on it saying it needs LSD fluid. But does a worn LSD act in the matter that mine is?

Not exactly like what one of the users said pervious owner might've switched the third member. I had the sticker as well when I first got my corolla. I was tryna clutch kick it wasn't working. So maybe I wasn't doing it right? Weeks after I got my car the ring and pinion blew. So this was the perfect time to check. I pulled it out and it was a OPEN diff. So I just picked up a third member with a welded diff for quick repair. Till I have enough for tomei 2way.

Also 2 way for drifting
1.5 way for grip etc. IMO, IIRC

I wouldn't trip out about the tires spinning opposite ways, I've had most OEM LSDs do that. Only like aftermarket diffs will spin both in the same direction. I don't think the OEM one has a lot of tension against the plates until you get on it and lock it up. Burn out test broseph. Straight line, drop the hammer Cole Trickle style and compare the skid marks from a launch. Equal width is Jimi Hendrix LSD trip, one kinda skinny is butter face girl sad.

HASport AE86 wrote: Equal width is Jimi Hendrix LSD trip, one kinda skinny is butter face girl sad.

Oh gosh. There you go. Haha

Dude, that's quoting the FSM. Or you can try to do some donuts (aka bagels) in a clockwise rotation. Open diff will do bagels turning left, LSDs that are working good will let you spin to the right. Just don't do it where you're gunna look like a jack@ss like a neighborhood.

If you jack up the rearend, put the car in gear and rotate one of the tires, I would expect you would feel some resistance even with a blown lsd. An open diff defintely feels open with no resistance. You could try removing the fill plug and shining a flashlight in the hole to try and see the diff case. You'll be able to see the spider gears on an open diff since the diff is not enclosed. An lsd will look like an enclosed can.

Pull the axles out
and then the 3rd member
no point in guessing what you have when you can find out for sure in about an hour or two with a little bit of effort

Max

HASport AE86 wrote:I wouldn't trip out about the tires spinning opposite ways, I've had most OEM LSDs do that. Only like aftermarket diffs will spin both in the same direction. I don't think the OEM one has a lot of tension against the plates until you get on it and lock it up. Burn out test broseph. Straight line, drop the hammer Cole Trickle style and compare the skid marks from a launch. Equal width is Jimi Hendrix LSD trip, one kinda skinny is butter face girl sad.

You can't do the burnout test in PDX because the roads are never dry. On the plus side, the roads are always wet.

Then what is there to fear about spools, i heard weir makes some great ones that act like a welded diff..

anyone know who can do rebuilds on the rear end?
i'm having the same problem (spin one tire, the other spin different direction), AND there's no sticker 'lsd' on the rear end. Supposedly the previous owner say it was lsd.

weir is a good place to get a rear end rebuilt
Spence is a stand up guy in my book

Max

I was told this trick by someone a few years back. I think these instructions are right, but it's been a while and I might not remember the full details.

jack up ONE side of the rear end, and put the car in gear. try turning the suspended wheel forward. if it spins freely, then it is an open diff. if it gets stuck, then the LSD plates are working to try and get the other wheel to spin too.

Just out of curiosity, I was under the impression that the LSD rear ends were only available in GTS and of a different size. I'm not talking about gear ratio. I'm talking about dimensions. So is it safe to say that a GTS diff won't fit on a an sr5 housing and vice versa? Or am I ill informed?

kennyb01 wrote:Just out of curiosity, I was under the impression that the LSD rear ends were only available in GTS and of a different size. I'm not talking about gear ratio. I'm talking about dimensions. So is it safe to say that a GTS diff won't fit on a an sr5 housing and vice versa? Or am I ill informed?

You are correct... the 4AC equipped cars came with a 6.3" differential(diameter of ring gear), the GTS came with a 6.7" differential. A LOOOOONG time ago there were a few LSD offerings for the 6.3", but I don't believe anyone still offers it.

HASport AE86 wrote:I wouldn't trip out about the tires spinning opposite ways, I've had most OEM LSDs do that. Only like aftermarket diffs will spin both in the same direction. I don't think the OEM one has a lot of tension against the plates until you get on it and lock it up. Burn out test broseph. Straight line, drop the hammer Cole Trickle style and compare the skid marks from a launch. Equal width is Jimi Hendrix LSD trip, one kinda skinny is butter face girl sad.

off topic.!!!. i miss your old signature.. something like.." I DO everything blah, blah blahh ..except your wife..." lol shxxt made me laugh the first time i saw it

Another way to check is to remove your drive shaft and the pinion nut will be marked with a color. If I'm not mistaken if its blue you have a lsd. Not sure about the other colors. Hope this helps.

Just jacked my left rear and tried turning it while in-gear. It locked up like a pro, which surprised the heck out of me considering it's stock. Oregon life has been good to this car. Perhaps my rebuild can wait a while.

up

There is some funny misinformation in here.
If you jack up only one tire, put it in gear and try to spin the lifted wheel it will not spin. The other wheel is on the ground so it's not going anywhere. The driveshaft is locked because it's in gear. Nothing will be able to move.
With one wheel up and with it in neutral spinning the wheel will cause the driveshaft to spin. If it has an LSD it may be more difficult or impossible to spin the wheel but that depends on the style and preload of the LSD.

If both wheels are up in the air you still want it in gear. If it's in neutral spinning one wheel could only spin the driveshaft or could spin the driveshaft and the other wheel. With it in gear the drive shaft and therefor the ring gear cannot turn. Now if you spin the wheel an open diff will cause the planetary gear to spin and the other wheel will spin the other way. Some LSDs will as well but again it depends on the style and preload. Even if the wheel spins the other way it will likely be much harder to spin with an LSD.
With it in neutral with no LSD spinning one wheel will likely make the other wheel spin the opposite direction but if the friction in the planetary gear is greater than the driveshaft it could possibly spin the same direction. On the other hand an LSD like Quaife's helical could allow the wheel to spin the opposite direction even in neutral if the preload was light enough.

In case anyone is looking for a new diff I can get Quaife and I belive Cusco, Kazz and possibly others if there are any other name brands available.

My understanding of the factory LSD is that it is designed to behave like
an open diff when not under load. So that in suburban cruising, mall carparks
and similar light load situations, the car turns and behaves as if it had an
open diff. When a bit more load (right foot) is applied, the wedging action
of the ramps starts to generate clamping force on the friction plates, tending
to lock both axles together.

At first the clamping force is not great enough to prevent some differential
movement, so both wheels will still grip the road without the one with the
least load starting skid. But increase the load (more right foot) and the
clamping load will increase to the point where the diff essentially locks solid,
and either the inside wheel, or both wheels will begin to skid

EDIT: When making a tight turn with the LSD locked up, the inside wheel
will start to skid/skip/chirp/squeal/whateva as it tries to rotate at the same
speed as the more heavily loaded outside wheel. With enough power on both
wheels will start to skid... donuts anyone ? And in a straight line either they
both grip or they both skid.

What this means is that when you check your LSD by jacking up both rear
wheels and leaving the transmission in neutral...
1. Turning one wheel gently forward, will result in the other wheel rotating
in the opposite direction just like an open diff, as there is no clamping force.
2. Spin the wheel forward suddenly, and the other wheel will spin in the same
direction. The sudden movement of the wheel has generated enough wedging
action to clamp the plates slightly, and now it behaves like a LSD should.

That's how it works with my factory LSD, and my LSD is still working fine. This
is only applicable to factory LSD's that have still got a bit of life left in them. If
your LSD (or any plate type LSD) has been shimmed up tight, you will have
clamping force at all times.

Cheers... jondee86

That sounds like a Helical. I believe at least some of the LSDs TRD and maybe stock too are helical.
The helical diff should have some preload on it. If the tires spin opposite direction with no resistance I wonder if it means it has lost it's preload? Or maybe the stock diff just uses a very light preload.

Here is a great thesis on the design and operation of the Quaife helical LSD.

http://www.google.com/url?sa=t&rct=j&q= ... WM&cad=rja