GDaina

Coming home from friend's house, the rear ends started to howl when I coated but was ok under power...drove home about 60 miles. Next day I look and see a puddle of gear lube. Jack up the 68 and and the pinion nut is finger tight, did not need a wrench to turn it..

I'm assuming the pinion bearings have seen their better days.

Couple Q's, I assume I can pound out the race without removing the case.
Tightening the pinion nut, specific torque? Or tight when there is a drag?

Any help will be appreciated.

DUB

WRONG!!! DO not attempt to do this. The torque at this area is specific.
There is a crush collar there and the pinion depth is important to make sure the ring and pinion are wearing/meshing correctly and allowing the correct backlash. Attempting to do this while it is in the car can cause/create catastrophic results. It requires a visual when this is being performed...thus requiring it to be removed.

DUB

GDaina

Understood...

How much of a crush? Or should I just fork over 20.00 to NAPA and they set it up for me?

Actually the 20.00 includes r&r the race...I take it home assemble and bring it back for the nut install

TimAT

There are 2 bearings on the pinion- front and back. If it was that loose, the rear end really needs to come out for a real inspection. Close look at the ring and pinion, and at the very least, new pinion bearings, crush sleeve, seal, and pinion nut. I'd bet the ring and pinion are scarred up and ugly.
Sorry for the bad news. On the good side, if you have an engine stand, the differential is not all that tough to rebuild. It takes some time, a torque wrench and some paint to mark the gears. Then figuring out which way to add/subtract shims to get the correct pattern.

wombvette

It probably has just loosened up because someone changed the seal and didn't get it tight enough. It wont hurt to just tighten it up and test it. My opinion, it will be OK. Stake the nut when done.

GDaina

Seals were changed in 2001

WVZR-1

If you're a gambler and at this point it may not hurt to try a "roll" - buy a crush sleeve, a seal and a new pinion nut and put it together using accepted install procedure. A drain, fill and a drive will tell you if the money was well spent. The time I'd think minimal. The alternative substantially more effort, might as well do it all then so there's substantially more money involved.

If you're not comfortable doing it yourself have it done.

wombvette

The fact that the nut was loose tells us that the nut is loose, not that the bearing is bad. The nut wouldn't be loose if only the bearing has failed, because it would still be tight against the crush sleeve. I know that the proper procedure is to measure the pinion preload, but the thing is in the car. I also know from experience that most of the time a crush sleeve that has been previously installed and set up will be close if you just tighten it up. On the car you cant do the measurements but you can turn the pinion by hand to get a good idea if it is correct. So what have you got to lose?

wombvette

Sintered bearings in a rearend?

1969Corvette

In your case if you replaced the seal then the nut was more than likely not tightened down correctly. At this point you have nothing to loose by just tightening the nut to the right torque spec. rotate it by hand to make sure nothing is bound up and you should feel between 005 and .012 backlash (movement between gears). Do not over torque this as you will crush the crush sleeve causing more backlash and then you will be removing it from the car and starting over.

Hopefully you did not drive it long loose and all ends well. If it has damage you won't hurt anything that you won't be replacing with a rebuild.



There maybe a flat side to the pinion make sure the nuts lip is pinned in at that flat spot

Rally68

You've got nothing to lose by tightening it up and driving it; if it's trashed you'll have to rebuild it anyway.

IMHO there's not much point in changing the front pinion bearing if you're not going to change the rear--it's just as likely to be damaged. I would pull the yoke and change the seal, though. Grease the new seal and use some gasket sealer on the outside. Note that it doesn't go in flush; there should be about 1/8" gap between the lip of the seal and the case. Also coat the yoke splines with the gasket sealer. Use some red Loctite on the pinion nut.

Good luck, let us know what happens

DUB

My .02 cents worth. Pull it out and fix it correctly. Because guessing on how tight to tighten the nut...even if you begin to feel resistance against the crush collar/sleeve and stop is NO GUARANTEE that it is correct.

And if you need to...I have a few customers in my database that can tell you how it feels when you break a tooth off the ring and or pinion gear and it gets lodged in the rolling rear assembly and locks up the rear end and moderate/high speeds. Outside of the few choice words obviously used during this experience...you may have to replace the drivers seat cover and or cushion because it got sucked up "somewhere". And YES...they did their own pinion seal replacement and messed with the pinion nut.

Do as you wish and best of luck.

DUB

GDaina

How can the nut work loose when I've put almost 8k miles a year since 2001...that's what I don't understand...

will pull the front bearing out tomorrow, (Saturday) and see how it looks..I got have both bearings, sleeve, and nut from Napa, so, will see what the verdict is on the bearing...

As I said above, there was no indication of any problem driving to my friend's except that I almost lost the left front wheel...the cap came loose from the knock off wheel, the pin came out, the knockoff worked its way loose and came off, and the fender lip was on the top of the tire...I did have a hell of a shake. Stopped the car without the wheel flying off, called my friend, came with a jack...I found the knock off, got the wheel back on and I have a set of safety pins in the car. Then on the way home, I experience the rear end howl when off the gas...