1963 Limited Slip diff

[jwwseville60]

Does anyone know what kind of LSD diff Caddy used? It was an option.
Can you add a modern one to a 1963 rear end?
Thanks!

[jwwseville60]

Found it.

https://6364cadillac.ning.com/profiles/blogs/differentials

[Chopper1942]

They used a set of clutch packs inside the ring gear carrier.  When a wheel would spin, centrifical force would force the clutches together and lock up the diff.  This type is still used today in some applications.  The problem you have is you need to find posi ring gear carrier that interchanges with your rear diff. Might be difficult because it wasn't a real popular option back then.  To buy a new complete unit, if one is available to fit you axle, will be very expensive.  The correct gear oil must be used or the clutches will lock up and chatter when turning corners.  The good posi-lube in the 60's & 70's used sperm whale oil as an additive .  It was banned and the lubes today do not work as well.  Personally I would not go through the bother and driveability issues to install a posi diff. I doubt if you are driving on gravel or muddy roads on the car in snow and icy conditions, or drag racing it.