The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)

- The 1967 - 1972 Chevrolet & GMC Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=3)

- - Roaring (https://67-72chevytrucks.com/vboard/showthread.php?t=798431)

Hello I've been away from the forum for awhile,I suffered a head injury and I'm just getting back to my C10 addiction.(I tried a patch but it was mopar)
The other day I noticed a hint of a vibration and quiet roar,I assumed it was hanger bearing and greased it but wasnt it. So yesterday I drove the truck to try and figure it out but it stopped roaring and went straight to grinding,luckily I was just a block away. I frared the worst when I pulled the inspection plate the image is what I saw,I re tightened the pinion nut & the noise is gone. I don't know much about rear diffs should I replace the crush seal? Or Will that even help? Truck is a 1972 C10 Highlander edition, and the ration is (I'm guessing) is close to a 3:73. I've had probably a hundred car/trucks never seen this before.
I would appreciate any info. Thanks guyshttps://photos.app.goo.gl/n4LziVmh5qAySfGY8
BTW ive had the truck since 2015 and I think it has happened b4 cause the grooves look deeper than if it had just happened.

First of all, welcome back.

Can you post a picture of what you're talking about? Was the noise primarily under acceleration, under deceleration, or at a steady speed?

Here's the link for the photo he posted.

https://photos.app.goo.gl/n4LziVmh5qAySfGY8

Looks like the pinion nut came loose allowing the pinion gear to rub on the carrier inside the rear end. Maybe someone knowledgeable about rear ends can comment on what repairs might be needed after something like this happens. OP stated they tightened the pinion nut and the noise went away. But what are the long term problems?

That looks nasty....

I would be concerned about metal dust contamination throughout the entire rear axle unit....

IMO....the rear end needs to come out and be fully rebuilt with new bearings, crush sleeves and seals....as a safety mechanism, I always use Red Loctite on a NEW pinion nut after I get the preload values correct....

You may be able to just get away with a new nut and loctite, but it really needs to come out and be done correctly....

:chevy::chevy::chevy:

Quote:

Originally Posted by AussieinNC (Post 8646607)

Yup. When one considers how fast parts wear out in a diff when they are only a little out of kilter, this has disaster written all over it, unless the diff gets put in a junk yard dog that doesn't go anywhere. Then it'll last until the second coming.

The pinion bearing definitely needs to be replaced at a minimum. You're driving a grenade with the pin pulled...

What everyone said, it's eating itself. Rebuilding it from the ground up is what is needed.

I have tightened up dozens of loose pinion nuts and then drove them. Its not the best fix but should be fine depending on bearing condition etc.
drive it and see what happens, the bearings are more durable than you think.
Now if your hauling heavy loads or have to have it 100% then rebuild the rear end. If the bearings are bad it would make noise even with the tightened up pinion nut.