For the 8¾” differential, there are four different limited slip versions:
The Clutch-type. When the differential side gears are in use (on turns or when tires slip), the side gear shafts push against and slide on the “V” groves, which engage the clutches. The more slippage, the more pressure engaged to disks.
The Cone-type (what you have). This one is made by Auburn, but yours will be similar. It uses springs to push the cones into the case iron case.
Eaton Tru-Trac. It uses a series of gears to provide the locking.
The “
open” differential and not worth reinstalling into any vehicle (ie: NO limited slip).
8¼” and 7¼” limited slip differentials are similar but not look exact. The “V” or the springs will be the same, though. Unless a recent changed, the Eaton Tru-Trac is not available for FMJ’s (which is a shame).
All FMJ’s that had a factory limited slip installed are of the Cone-type.
The Cone-type and Eaton Tru-Trac can use normal lube. The Clutch-type needs a friction modifier added to the diff lube or you will have clutch chatter every turn you take.
Nothing wrong with using a Cone-type carrier – just as long as it is holding. If it is shot, then someone has a new doorstop or boat anchor. When both rear wheels are off ground (and car is in park), take either rear tire and turn it. The tire shouldn’t turn or can if you take excessive measures to do so.
BudW