12 bolt help
 

Had my 12 bolt completely rebuilt. Ran great for 500-1000 miles. Then I decided to do a pretty massive burnout. The rear end started howling pretty bad after the burnout. What would be the most likely cause of the howling following a burnout?

Re: 12 bolt help
 

Supposed to change the oil at 500 miles (Break in period)...Did you follow the break in procedure? have you popped the cover and inspected the oil and gears? You may have burnt it up...Take it back to the shop.

Re: 12 bolt help
 

If it was a Posi, did you use proper posi [ltd slip] gear oil: [GL-5] + anti-friction additive?
Usually bearings ''howl''. Just a lot of places with bearings in a differential.
Broken axles go: "Craack!''

Re: 12 bolt help
 

Too much right foot! :metal:

Re: 12 bolt help
 

Do you have positraction? Does it howl all the time or just while turning one direction?

If an open diff, you may have burned up spider gears. Pinion nut could have loosened changing gear engagment. Either pinon or carrier bearings could have overheated. Carrier bearings usuallly howl louder when turning, pinion all the time.

Sounds like it has to come back apart...

Re: 12 bolt help
 

Its a posi and I followed break in instructions and had all the right fluids in it. Consensus seems to be pinion bearing...

Re: 12 bolt help
 

I had a slight howl in my rearend the entire time I have had my truck. I had a posi installed this week and the mechanic checked and replaced a bad pinion bearing. The howl is gone. So that may be your issue.

Re: 12 bolt help
 

It howls at all times. I'm gonna have my guy look into the pinion bearing

Re: 12 bolt help
 

I would not diagnos the problem for your mechanic. I would take it back and and simply say it started howling after a burn out, can you look at it?

Re: 12 bolt help
 

I already took it out and he is just waiting to work on it