From:             GSMnow at aol dot com
Date sent:        Mon, 23 Nov 1998 01:56:07 EST
To:               Voyn238 at aol dot com, Toyota-Mods at cyberauto dot com
Subject:          Re: 5M-GE stuff / 83 Supra.

In a message dated 11/22/98 1:59:43 AM Central Standard Time, Voyn238 at aol dot com
writes:

<< Is there a website that explains in detail how to rebuild a LSD?  I think
 mine's on the outs.  Or maybe someone who knows how can write it up and send
 it to me? >>

The Supra LSD is actually quite easy to set up. I have now done it three
times. I beat mine up, and will have to do it about twice a year now to keep
from blowing it apart again.

You jack up the car, put it on good jack stands, drain the fluid from the rear
end, Take out the half shafts. Pry out the stub shafts from the sides of the
diff housing. They come pretty easy, but be careful of the seals. Now take off
the rear cover. Make sure you have no chunks of metal or gear teeth loose in
the bottom, that is not good, I know!! All too well!!

Now you need to start being careful. Take off the bearing caps, two bolts on
each side. There is a shim on the outside of each bearing, don't mix them up,
they are selected thickness to center the ring gear. Also the bearing races
will come off when you pull the diff out, keep them on the correct side as
well, they will interchange, but then they will probably wear out real quick.
The diff itself is pretty heavy, and it want to fall right on your hands. It
is a good idea to put some wood under it so when it falls it does not damage
the gear teeth. 

Once it is out the real job begins.

Do this in a clean well lit area. Take out the 8 bolts holding the carrier
together. The springs will force the carrier apart. The first thing to do is
remove the 4 springs, and the two spider gears. Then put it back together with
a couple bolts. Use feeler gauges to measure the clearance between the cutch
disks behind the side gears. This should be .015 to .025 inches. The cross bar
that had the spider gears on it can rock side to side, if it can hit the
carrier, it is WAY to much clearance, this is what trashed mine. Now that you
know how bad yours is, it is time to fix it.

Take the carrier back apart. Keep all of the parts in order. Behnd the side
gears there are two shims and a clutch plate. The clutch plate rubs directly
on the back of the side gear. If this surface is scoured up, you need to
replace them. They are not cheap, but worn parts here will be a constant
problem. The shims all have numbers on them, you should have no problem
reading them, it is on the tab that keys it into the carrier. Bigger number
thicker shim. They have 1 through 6, I don't remember the thicknesses, I had
it from Alldata, but I am sure the Toiyota Dealer can get it for you. The way
it is made, the shims don't wear, so you can figure back what shims you have,
and get thicker ones to get the spec back. If they are already too thick, and
you need more, then there is wear that needs to be addressed. The Thrust
Washers between the side gears and the cross bar are prone to wear. When you
replace these, you need to take the clearance measurement all over again, yup,
put it together without the springs, and see if you are in range. I am running
mine tight, but anything under .025 inch should work good, I am close to .015
inch. If you run it too tight, it will chater bad, and probably fry the
clutches. The thrust washers run on the cross bar, and it will wear. Just shim
for it and go, the cross bar set is over $300 US from a Toyota dealer. When
you have a set of shims that works right, putt the spider gears on, and
install the springs. You might also want new springs, this will give a bit
more pre-load. I have found it easiest to assemble all the parts in the
carroer, and push the cover down on it, but you have to make sure the tabs
(keys) on the clutch plates and shims all fit into the slots on the cover.
Then make sure the side gear centers properly also. Tighten the 8 bolts slowly
and in a criss cross pattern. If it binds, stop, you can bend the cover. If it
goes all the way down smoothly, insert one of the stub axles so the splines
engage, and try to turn the diff. It will be tight as the clutches should now
have a good grip. But it should turn smooth without binding. 

It is a good idea to use locktight blue on the bolts when you torque them. If
these come loose, it will be a mess.

Installing the diff back in the car can get FUN. Put the outer races on the
bearings. Then push it up into place, while holding it up with one hand, try
to insert the side shims back where they came from. The shims should make it
tight enough to stay in while you get the caps in place. I had to tap my shims
in with a mallet. Once the caps are on and torqued, you should be able to turn
the drive shaft and the diff should turn smoothly. (trans in neutral of
course) Now install the cover, I use silicon RTV to seal it up, install the
stub axles, then fill it with a good LSD rated gear oil. 

Re-install the half shafts, and you should be all set.

Gary M.

P.S. is someone going to copy this to the FAQ??