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1959 Differential Rebuild Question


New member
Feb 11, 2023
Williamsburg, VA

I have an 8.2 drop in differential that I'd like to rebuild. The issue is I have just one of the bearing caps. Is it possible to use one from a different casting?

Thanks in advance!
Welcome to the Corvette Action Center.
The side bearing adjuster threads were machined with the caps on and torqued in place. It would be very hard to find a cap from another carrier where the threads would align perfectly once installed. Unless it's a number and casting date match to your car it would probably be easier to find another carrier to rebuild. If you can find another bearing cap, it will probably be on a differential carrier that it matches. I don't know if anyone has ever tried to machine the case and cap then have it align bored and re-threaded. In theory it could be done but the ring gear will move closer to the pinion and the pinion might not have enough adjustment left to get a proper mesh.

Thank you Tom - yes, it is a date coded casting and that's why I'd like to use it. It's for an early 1959 and honestly there were so few posi's made (I've been searching for years) that realistically this is my only option. Am hoping someone has successfully dealt with this in the past, but your thoughts are much appreciated.
My 59 is an early car too. The original posi is long gone and I should have been looking harder back when they were not so hard to find.


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