Pinion Seal on 60's 10-Bolt Rear End.

[LONDON55COUPE]

The rear end on my '55 is from a 60's Camaro or Nova I believe. I haven't actually driven the car with it installed, but I have fitted all the 55-57 brackets and put in new brake wheel cylinders, brake lines and brake shoes. It is a 3.36 ratio and the driveshaft connection is the same as a 55-57 as the driveshaft will bolt straight up to it with no mods. I put the axle lube in about a year ago and have only turned it by hand. While I was putting in a new rear emergency cable at the weekend I noticed that I could see a slight weep of oil around the edge of the pinion nut. It wasn't dripping or anything, but like I have said it has only been turned by hand, so I don't know if this will be bad once the car is on the road. I have heard of some engine and transmission seals drying out through lack of use and leaking, but sealing up again once they have swelled up when back in use. Is this the same with a pinion seal?
Apart from taking off the rear cover to visually look at the gears and calculate the ratio, I have not done anything to the inside of the rear end. Is it a big job to change the pinion seal, or is it just a case of undoing the large pinion nut and accessing a seal from that same side. I have no exploded diagrams of this to see how it all goes together. If it is a major job of pulling axle shafts etc, I might be tempted to leave it until I have tried it on the road first to see if it is worth worrying about. Your advice would be appreciated as would an exploded diagram.

Terry

[big gear head]

If you noticed the oil around the nut then the seal isn't the problem. The yoke needs to have sealant in the splines to keep oil from seaping through them and out around the nut and washer. Many people install the yoke with no sealant in the splines, and they leak. You can remove the yoke, clean out the splines, smear some sealant into the splines of the yoke (not the pinion shaft) and install the yoke again and your leak will stop. If the seal has never been replaced then this would be the time to do that too. You can pull the seal out from the outside and install a new one. Just be sure that you smear a little sealant around the outside of the seal before you drive it in. Then grease the lip of the seal before installing the yoke. Torque the nut to 150 foot pounds and use red locktite on the threads.

[LONDON55COUPE]

Thanks big gear head, that sounds straightforward. I'll have to see if I have a big enough socket to get the nut undone now. Also I might order up a new seal. I am presuming the 60's 10-bolts would all have the same seal?

[big gear head]

If this is a Chevy 8.2 10 bolt then it will have a 1 1/8 inch pinion nut. The 8.2 uses the same seal for all years from '65 to '72. If this is a BOP 8.2 10 bolt then I can't remember what size the nut is, but it will take a different seal than the Chevy 8.2.

[LONDON55COUPE]

Managed to get the axle yoke out today. The seal looks fine and clearly wasn't leaking, so it must be coming through the splines. I am going to a car show on Friday so I will get some more threadlock and sealant. I think I will leave the seal alone for now as it is not leaking and I don't want to drain down the axle again. Now that I know how it's done I can change it in the future if it does ever leak.

[Belairmark]

See you at Wheels Day!!