So I'm doing a rear axle bearing job. I had the center pin out, both axles out of the rear axle, diff cover off. No loose hardware was in the diff. Had a shopping bag covering the diff since no cover (my trucks outside). The diff looked like it was in pretty good condition.

While I was waiting for parts im diagnosing an electrical issue. So I start the truck, in neutral, with the diff in the condition that I said above. I hear a couple clunks then the clunk stops, trucks running.

Upon inspection I see the shopping bag sucked into the back of diff. Wont come free so I didn't tear it out. Driveshaft wont spin and diff wont spin. Hammered on the driveshaft 5 times and it only budges a little.

Before I take my diff apart I would like to know how bad I just screwed up my truck. All the gears looked fine. My first thought is to take the drive shaft off and see if I can spin the diff to free the shopping bag. Also to see if its my driveshaft locked up, or the diff.

If I could get some pointers as to what I could have done to the truck by making this mistake it would be appreciated. Where would you start looking, what components may be damaged?

Hoping I don't have to look inside the transmission because I broke something in there.

The clunk was definitely not a starter noise clunk, it was brief right when I started the truck. Trust me you don't know how stupid/frustrated I feel.

 

I would expect that the bag has jammed up the works..... The rear shaft will spin under no-load conditions, even with the trans in neutral. (as you discovered.....) Drop the driveshaft, or, put the trans in neutral, use a big pipe wrench to spin the diff the other way, to get the bag out. It's just plastic, so, I doubt there will be any lasting damage.

 

Everything is fine. Loosened the main bearing caps, keeping them in, and slid the diff gears forward off the pinion gear. Bag came right out in one piece. No shredding or left over material left behind from the bag.

Tightened Main bearing cap bolts to 100 ft lbs. Spent 1 hour getting the rtv off the gasket surfaces. Installed Felpro gasket and tightened cover bolts to 35 ft lbs.

Took it for 1/4 mile drive and I noticed major improvements from the bad bearings. Got some more work to do but will highway test it soon. Guess that goes to show the tolerances of the gears, I dont have a backlash gauge but I can barely move the diff back and forth. They gooped the crap out of it with rtv so it kept all the fluid. Cringed a little seeing excess rtv squished to the inside of the diff.