Shims and or Shimming a Skyline Lsd for to proper spec?

[Supraclean]

Hey guys,

I usually don't post as Gtrc and Gtruk usually have the answer for me when typing up whatever I need on google.
this time is it different.

Here is the story:

What I am trying to do is install a 2way locking LSD made by either Osgiken/ or tomei in my R32 Gtst Viscous diff housing. (Previous owner is very reputable and used it has a backup for Formula D)




Now I took the liberty of ordering brand new Nissan side bearings, seals, pinioin bearing and seal to basically have a brand new diff with the new locking diff.

Now using this guide was simple and helpful I find a lot of important info has been left out:

http://www.nicoclub.com/archives/aftermarket-differential-install.html

Once everything was put back together and pinion torque was set to spec( using R200 specs) my backlash was way to tight.

Not sure if you can view this document but I have a PDF file easy to find on google that has the Final Drive for R200 diffs that lists a lot of good info.

One thing reading over the PDF I notice it says not to reuse the Pinion locking nut.... Could this possibly be throwing my backlast out of whack?

Shop owner and buddy that is helping me says that my backlast is way to tight and that I will rip my teeth off at this seting. They are suggesting I order pinion shims and side bearings shims to play around with the settings until we get it within spec.

This is just a nightmare, I have a bunch of parts numbers but not sure what to go with.

Has anyone had problems or experience setting up a locking 2way diff?

[GTRPower]

What they suggest is correct.

You can also check run out on a lathe. I would also check stack height side to side. If the new LSD has taller stack heights on both sides compared to the old diff, you can turn them down to fit the case and old shims, but that is a bit crazy to do just to avoid using new shims.

[Supraclean]

We have a couple things to try, ill keep ya post but that sounds skechy Kunio!

[Supraclean]

Well I want to follow up on my little experiance.

When the new bearings and reuseable shims are put but in the pinion (there are two of them) make sure to look at both sides of the shim.

There is a comcave that is placed Backwords will throw out your clearances and your backlash.
First time rear differential install. Now I know so I figured I eould share just incase you run into this problem.

[GTRPower]

Spring washer is for preload. Glad you figured out there was one there. Cheers!

[Dragon Humper]

So the Nissan diffs use a spring shim instead of a sleeve to keep the brgs spread apart as you set the pre-load on the pinion? If that's true your lash would have been too loose, not too tight. Something doesn't sound normal there. Did you use a torque gauge to set the brg drag on the pinion? If you know what to feel for you can do it by feel but with new brgings you really should use a torque gauge. New brging need to be set a little tighter than used to compensate for run-in.

I'll check the bible .....

I see what you did, the spacer shim (closest to the pinion gear) has a bevel cut into one side for clearance of the fillet that is cut into the pinion so there is a smooth transition from the shaft to the gear. I see that Nissan uses a solid sleeve and a shim to keep the brgings spaced apart (kinda goofy and really labour intensive for no reason) and that the preload is set to .5-.7 ft-lb (.07-.10 kg-m) front and .7-1.2 ft-lb (.10-.16 kg-m) rear. That is without the oil seal in place and measured as you rotate the pinion (need a digital torque gauge or a very sensitive bar bendy style).

I guess they had their reasons (it would keep the pinion very stable under alot of stress, like HD trucks) but a spring sleeve is MUCH easier to deal with than a solid sleeve and a shim. I can see why shops charge an arm and a leg to install this stuff. New gears and LSD would be a hair pulling session and a crap load of shims to instal from scratch.



Jon.

[M13]

DO you have a picture of the new diff innard next to the OEM piece?

Is the clearance ok now?

[Supraclean]

I do not have a pic of the new diff innards compared to the Oem. Yes clearances are great now Ill report but once break in is done. I have a tune date coming up.