AE86 GTS rear end problem

androssyae86
Club4AG Regular
Posts: 11
Joined: Wed Jan 15, 2014 8:12 pm

AE86 GTS rear end problem

Postby androssyae86 » Thu Aug 14, 2014 9:06 pm

Hello fellows.

So when i'm driving and let off the gas, say if i'm in third or fourth gear, I hear a noise coming from the rear axle. Also when i replaced the diff lubricant a few months ago, there was a decent amount of metal shavings that I found inside the drain plug. anyways, my brother and I went down under and the driveline when we twisted it left or right is loose or easy to turn so to speak.. Is this normal? Do i have a differential issue or a driveline issue that's causing the noise? It's hard to describe, but it's almost like a winding sound.. idk. Hopefully it's a differential problem, cus I've read somewhere that the ae86 drivelines aren't serviceable.. Anyways, any advice would be appreciated. Also if anyone has a spare LSD diff or driveline in good condition lying around let me know.. just preparing for the worst case scenario :|

thanks very much

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jondee86
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Location: Wellington, New Zealand

Re: AE86 GTS rear end problem

Postby jondee86 » Fri Aug 15, 2014 3:58 pm

Universals are checked by holding either side of the joint and twisting. There should
not be any noticable movement in the bearings.

Shavings in the diff are God's way of telling you that your diff is in need of a re-build.
Unbolt the driveshaft at the companion flange closest to the diff (using match marks
so you can put it back the same way round). Grab the pinion flange and turn it forward
and back to check the backlash. In a healthy diff the flange will move maybe 3-4mm
at the edge, and you will hear a click as the gears touch together. If the flange turns
10-12mm and you can get a decent clunk noise, something is not happy inside :(

Now try and push the flange from side to side. You should not get any noticable side
to side movement. If the flange moves 3-4mm you have lost you pinion bearing preload.
Try pushing and pulling the pinion shaft in direct line... as if you were trying to push
it into the diff. If you get 2-3mm of movement your pinion is floating free and the
contact patch between the pinion gear and the crownwheel gear will be wandering
around. None of these things is a good sign.

Image

Look at the pinion seal... is there a lot of oil leaking out and spraying across the
underside of the car ? If there is, get that nugget out of there and down to a decent
transmission and diff repair shop for a re-build. Or, if cash is tight, maybe find another
one that is only half worn out and swap that in. But you need to grab the complete diff
head if you can, so you don't have to change bearings or try and set up the diff... unless
you have a lot of time on your hands and are possessed by the need to learn new stuff ;)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

azndrifter50
Club4AG Regular
Posts: 37
Joined: Wed Jan 16, 2013 6:18 pm

Re: AE86 GTS rear end problem

Postby azndrifter50 » Mon Aug 18, 2014 9:22 am

That is correct up above. Check your shims and more than likely will have to be replaced. Take it to a place where you trust because not many ppl know how to set backlash properly. Its not hard but not easy. Take cares.
Thanks,

Brian

Ae86 Ultimate
Master Mechanic and Master of the Custodial Arts
Los Angeles, CA