Limited Slip Rear Ends

[kilkm]

I would like put a posi-traction rear end in my '62 Electra. Does anyone know if the rearend assembly from a early 60's Wildcat would fit under a '62 Electra 225 or is a gear swap possible? Did all Wildcats leave the factory with limited slip rearends?

Thanks

[NTX5467]

I highly doubt that any Buicks had limited slip differentials in them as "standard" equipment. They can be more prevalent in some sections of the nation (i.e., northern states) than in other areas (i.e., southern states), though. Purely an optional extra . . . at a nominal additional charge.

In the general scheme of things OEM, the differential case (what the ring gear bolts to) is specific to a particular gear ratio spread. For example, one "case" might accomodate ratios from 2.93 to 3.42 ONLY. If you wanted to go to a 3.73 OEM gearset, you'd need a matching "case".

The difference is in the thickness of the flange the ring gear bolts to. Different gear ratios and ring gear thicknesses need different thicknesses of flanges to maintain a particular architectural relationship of the ring gear teeth (with varying pinion gear teeth numbers and resultant diameter) and the center of the pinion gear. In the aftermarket, they provide spacers to accomodate the deeper (higher number) gear ratios, but OEMs use the thickness of the flange.

The rear axle gears (ring gear and pinion) are not affected, typically, by whethe or not the differential case is an "open" case or a limited slip case. It's what's inside the differential case that makes it what it is, but each case is designed to be what it is (either non-limited slip or limited slip).

Hope this might help . . .

NTX5467