Replacing pinion seal
 

Am in the process of replacing a leaking pinion seal on my 64 Malibu. With the car jacked up and the wheels off the ground and trans in neutral I can rotate the drive shaft maybe a 1/4 inch either way without the tires rotating. I disconnected the driveshaft from the differential and then the input flange nut (much fun). After using a puller I was able to remove the flange and found I could move the pinion shaft side to side approximately 1/8 inch. This doesn't seem right but other than a slight oil leak from the seal the differential doesn't make any strange noises. Any suggestions on what to do next as far as the play goes ? Please don't tell me to install a Ford 9" rearend in it. Thank you again. As usual, everybody is a big help.
Harvey

If your pinion is moving that much...im thinking your seal wont last to long.
It may be time for a rebuild.
I just did mine with richmond 373 gears and the richmond rebuild kit.
Its not that hard of a job...if i can do it anyone can.

Pinion Seal Replacement
 

.I am thinking the same as you. The seal will probably leak due to the play in the pinion shaft. Who did you buy the rebuild from and how much was it ?
Thanks.

I tend to use jegs for most things
due to the no hastle return policy

Did you notice the side play before you removed the pinion shaft yoke and nut. Don't forget now with the yoke and nut removed your not preloading the tapered bearings. There will be some rotational play in the driveshaft. My 12 Bolt is out of the car right now and I just checked the rotation play seems to be about 1/8" total.

Thank you hkalin. I am going to reinstall the yoke with new seal and nut and see if the ply is reduced. If so, I will probably go with it as is. What I would really like is to find another 1964 rear end and have it overhauled along with a change over to disc brakes. So many ideas and so little money, no fun being poor. Thanks again.

Hope I'm not too late but I think they put a sealant inside of the spline in the yoke so no oil seeps past it.

Pinion Seal/Yoke/Sealant
 

I haven't installed yoke yet because I got the wrong size jam nut. The nut I got was for a 12 bolt and has a bigger outside diameter. Same thread size but you can't get a socket into the yoke well. I have a 10 bolt and must have called everybody on the East coast looking for a new nut. I finally found on the net a company that had them and was a pleasure to deal with. They probably lost money processing the order for a $5.00 part. They are , National Driveline, 877-910-2244. I'm going to put a thin coating of sealant on the splines, great idea and thank you.
Harvey