12 bolt rear baning and poping!!!

[ChevBlazin]

I was leaving church this morning and as I would drive forward the rear end was poping and banging (86 K5 blazer 12 bolt open carier and 3.73 gears), so I of course stopped immidately. I was in the lane of traffic so I had to pull off. The truck will not move forward, like you are power breaking or someting and then if you give it enough gas it will lunge forward a few feet and make a loud bang. It will still back up however. I had to leave it there and am having it towed to the shop I work at. What can I expect to look for when I take the rear cover off. I am thinking maybe a carrier or pinion bearing went out. I know the rear diff cover leaks, but not much at all and I checked it this summer. this is my daily driver and I need it fixed asap, unfortunately they guy that owns the shop is on vacation all week and it is 7 degrees out right now so laying on the ground doing the work does not sound appealing. Any ideas on what the problem may be would be appreciated.

 

[Beast388]

My old 12 bolt made popping and banging noises right before it shot chunks through the cover. I was driving in town at about 30mph....so I wasn't even wheeling it. I would bet you've got some serious problems.
/forums/images/graemlins/eek.gif /forums/images/graemlins/thinking.gif

I broke teeth off the ring and pinion gear, and bent the factory limited-slip carrier. /forums/images/graemlins/angryfire.gif /forums/images/graemlins/eek.gif /forums/images/graemlins/rotfl.gif

 

[R72K5]

check pinion nut, it probably came loose on you, is common problme that no one keeps an eye on

you will be looking for another axle now, yours will be scrap now, you should be able to find another for cheap,

 

[tRustyK5]

It'll look like it ate a grenade when you get the cover off. My old 12 bolt blew chunks through the cover while I was backing out of a parking spot...

You'll likely have to replace or rebuild yours.

I decided to go 3/4 ton instead of rebuilding a known weak point. The initial cost was about the same as rebuilding...plus there was the aditonal cost of new rims and tires. At least I knew I wouldn't have the same thing happen again...plus I got bigger brakes out of the deal.

Rene