Sound comes as im over 20 mph an humm pitch gets higher as i go faster..when slowing down slowly
it goes lower to a growl like. .almost sounds in middle area but i cant tell
Doesnt matter how the wheel turns or gas .Diff fluid ok an tranny fluid normal..no bubbles! .Diff cover shows that " leak look" but fluids fine an no drip.
Im gonna rotate wheels an see how it does soon.Then look at seal/ bearing.
Amything else i might look at..tranny.an drive shaft included ?

 

Does it change pitch with engine load??

 

Not really . Seems to be related to how fast an not the engines stress ..

 

Hhhhmmmm...... Carrier bearing in the rear diff?

 

Any way to check that carrier bearing while i got the differential cover off?

 

Only way is to pull the carrier, and physically inspect it. With the driveshaft off, and axles out, turn the pinion by hand, see how things feel. Should be perfectly smooth.

 

Thanks..Ill see how it does with the new bearings an seals 1st. Then that.
Whats the Ftlbs on the differential bolts ?



An does it take over 2 qts ? Mine has the round 10 bolt pattern.
Anything to do before 1st run / test ?

 

I set them at 30 ftlbs .
2 qts but will likely need a bit more..

UPDATE
Took it 50 miles same hum.
gonna be replacing a tire that has side cracking on it an rotating them.
An looking at carrier.
.

 

Still getting that hum -I moved tires an even changed 2 .

The upper control arm bolts werent extremely tight..
Im at a area now on back road where i can try anything on it fast stops an all.
it seems to be related to how fast im going .As i slow down the hum tone goes lower in pitch an higher as i speed up..Rpm an gas dont impact it an neither does quick turn of steering wheel. Any drive tests I should try with a empty back road?
Is that carrage checked only with diff cover off an stuff taken apart ?
Can drive shaft be unhalanced?
Thanks.

 

I would suspect a bearing problem in the carrier, given your symptoms. Did you inspect those when you had the cover off?

Driveshaft balance would give you a vibration, not necessarily a noise.