I just rebuilt my diff with a new Auborn Pro series carrier and 373 gears. All seals and bearings were replaced. Backlash was set to .008 in. I am getting aloud winding nois coming fromthe passenger rear. It is loud enough to where i can hear it over my exhaust without the muffler on. I believe everything isshimmed properly. I used the marking compund and the mesh looks real nice. Someone please help. Also replaced the u joints.

 

This should be posted in the "Drivetrain" forum..... moving it there.

 

Is the noise louder under acceleration or coast or during cruise? If it varies with load, it's probably the gears. If it's not load sensitive, but just rpm sensitive, it's probably a bearing.

 

Its when i let off the gas.

 

if it's only under coast conditions, it's possible you got a defective finish on your gear set.

try checking the wear pattern again, and make sure to do both sides of the teeth.

 

ok...until i get a chance to go back in there i would like to know, is this simply a noise concern right now or will it do damage?

 

i really can't say, but i'd imagine that if you don't do any engine braking, you'll be good to go for a little while.

 

Probably won't hurt unless noise is VERY loud. Rear gears can be strong without being quiet. The really good ones are lapped as a matched set for quietness, but not for strength.

You can't put anywhere as much coast load on them as WOT accelerating them does. Well maybe if you get it into 1st on a manual at about 50 mph with clutch disengaged, let the engine drop to idle then side step the clutch, you might be able to hurt something. My guess is the diff parts would break long before the ring and pinion. Usually suspension parts fail first.

BTW that was a test procedure developed in the 60's. The complete description of the test makes me wince to think of it. Witnessing it run was not a fun thing. Glad it wasn't run on my car!

 

ok....i have adjusted the shims by backing off .002 in. Noise is still the same. Any other ideas?

 

I think usually when coasting if the noise is louder the backlash is what is off.. Are you sure you checked your .008 right. Who makes the gear you put in there? Some may have a little different backlash. Most ARE .008 but its best to check the number on the ring gear just in case.

What did you back off .002?

I would also check all the bearings while your in there. I took one apart one time and the front pinion bearing was shot. Throws your measurement off a little.

Last thing... I've heard the limited slip units can make some noise if you do not use the additive.

 

I used the additive and the .002 was how far i backed the ring gear off the pinion gear. All of the bearings were replaced.