I read the 1989 service manual on rebuilding the borg warner limited slip unit. basically it is the same as that procedure found here by mr. hunter. except it recommends the max shim being .010 depending on diffential case measurements. I guess if the measurments don't fall within GM parameters, they would recommend replacing the diff.

anyway the re-assembly procedure calls for mixing gear oil and the ADDITIVE together, and applying it to the parts during assembly. It gives the chemical name for the additive which I forgot now. So it seems to me the additive is neccessary.

also I have found shims. 2.25"od x 1.5"id at .018 thick and also .036 thick. they are expensive $10 each, made from A4-3 material. but it beats wasting many many hours searching for shims, and money wasted trying different things like below.

I also found 2.125"od shims x 1.5" at .005 thickness. I'm not sure these will work cause the OD is smaller. I'll see when I pull my posi apart.

I also wasted $30 on what was suppose to be "layered shims" that peel off layers to change the thickness by .005 for each layer of material removed. sounded like a great solution, but that turned out to be bogus, and a waste of money.

so if you want the shims mentioned above, write me.
larryburd@mail.com

 

Larry -

Obviously this is a topic near and dear to my heart at the moment.

Just to beat a dead horse - your 1989 manual was written BEFORE the October 1998 TSB stating that the additive should not be used in the gear oil.

Regardless of whether or not you use the additive, when do you plan on shimming your posi unit? I would be very interested in hearing about your experience. Cost/time/difficulties/results.

Thanks for the post.

PS I had previously been told that the 9-bolts are "not serviceable". Given that your manual (I assume a GM manual) provides the procedure, this is another thing I had been told that is untrue.

 

also I just found out..... it seems the axle seals for the 9 bolt are different from right to left. I havn't figured out why yet, but they are pricey too. like $13 for one, $16 for the other.

Larry