My '56 Oldsmobile rear end has a leaking pinion seal. ebaY sellers and Summit all list the same seal for '50-'64 models. I know for a fact that the rears were significantly redesigned in '57 and most parts don't interchange between eras. The sellers list differential paper gaskets the same way so I ordered one and it was 1 1/2" too large in diameter for my earlier rear. Don't want to spend $35 on the wrong pinion seal!
You can pop the seal out, take accurate outside/inside diameter and thickness measurements and find a match that way.
Yes, that's plan B. Am on vacation and wanted to order it so would be there when I get home if possible. Guess I could go to local auto parts store but lately have found they just carry parts for late model econo-cars.
Thanx. Like you say, they only advertise the 9.3" , '57 up units. Will give them a call though, thanx.
SFK 19438 - pinion seal is the part you want. 54-56 Olds you don't want gasket RDS6431- wrong gasket this is too big, but what alot of the big houses sell as fitting the Olds, ask how I know. And makes it worse when you pay to get 2 of these to Australia. The gasket you want is 10063E I think its a Best gasket. its for 53-56 Olds read ends
rockauto shows it fits from 54-62 https://www.rockauto.com/en/catalog...5711,drivetrain,differential+pinion+seal,2380
I think I solved the problem. I made my own gasket w/ paper gasket material and I called https://fabcraftmetalworks.com/ recommended by 34Phil above and he hooked me up with the proper pinion seal which is leaking like a sieve after being in service for about 60 years.
Willys36 I did look it up and the results are; CR brand: 53-56 #19438 57-62 #19438 (the rear pinion bearing is different) National brand: 47-52. #6244 53-62. #6654N 63-64. #8163N Pat
Will check that when I get the yoke out. I'm hoping it is just 60 year old rubber that's the problem.