re oil coming from rear end.

[Wayne64]

I understand it is normal to have some oil drip from the rear end were the drive shaft yoke enters from the transmission. Is this a difficult fix ? Can the seal be replaced without taking out the rear end ? Any help would be appreciated.
I believe a synthetic oil is in the posi rear end.

 

[Hib Halverson]

I understand it is normal to have some oil drip from the rear end were the drive shaft yoke enters from the transmission. Is this a difficult fix ? Can the seal be replaced without taking out the rear end ? Any help would be appreciated.
I believe a synthetic oil is in the posi rear end.

No.

On a car that old, you need to overhaul the rear axle. You might be able to replace just that seal but on a diff which is 43 years old you're far better off pulling the axle and having it rebuilt.

 

[GTR1999]

Your differential can leak from the pinion yoke area, side yoke area, cover bolts or broken/cracked rear cover. Commonly the pinion seal leaks but if the side yoke wear enough they will grind into the housing where the yoke seal is. There is a 1/8" boss cast and machined there. Using longer spring bolt s will crack the rear cover and it will leak.

Look over the diff to see if you know exactly where the leak is. With your as Hib said it may be time. The thing with original 63 & 64 posi's is the case is not good and not rebuildable. If it's been changed in the past then you probably have a Eaton posi in there unless it's an open diff?

It is possible to replace the pinion seal in the car. If you go to www.digitalcorvettes.com I have a procedure in the c3 section under the title rear suspension index. It will walk you through the job with pictures. I have one on custom rebuilding the diff as well.

 

[Wayne64]

Thanks for the help.
I believe the oil is coming from the front yoke seal only. Might be a good time to change the 3:08 to 3:11 better highway. I will check out the web site.

 

[GTR1999]

vette gear ratio's for your car with a 3 series case are
273,308,336,355,370,373, 390,411,and 433. Some are aftermarket US gears made for Tom's Differentials.
Be sure to use #2 on the yoke splines and check for a scored OD requiring the speedy sleeve.
Let me know if you need any help or have questions.