Noise in rear diff - Opinions?

[koda2000]

'01 ST 4:10 LSD - Ok, so I thought I'd identified/fixed the noise coming from the rear of the truck by cutting out a small piece from the rear inner fender (there were fresh signs of tire contact on the passenger side) but the noise is still there. It's quite loud while driving with the rear window down. It sounds just like a tire rubbing, (rub, rub, rub sound) but now I believe it's bearing related. I can't tell if the noise is coming from the center, right or left. The noise almost goes away under light throttle, but is heard under heavier throttle or while decelerating. I have to pull the rear axles to change the axle seals, so I can check the axle bearings easily, but IDK if the noise is more pinion bearing related. While the rear brake shoes are worn and oil fouled, I don't feel the noise is brake related.

Any opinions as to where/what to look for?

 

[jamie3529gq]

having just replaced all the bearings in the rear axle of my mountaineer last weekend, it had a gear 'whine', it was the pinion bearings. I read somewhere that carrier bearings 'growl' when failing, pinion bearings 'whine' and wheel bearing noise changes when you load up one side or the other in a turn. Parts to replace them all (carrier/pinion/wheel) in my truck cost about $200 including oil, to install them took me two days, and involved a lot of cussin' and stoppage for smoke/beer breaks. But it cured the noises from the back of my truck!

I had a Mustang Cobra a while back, the rear diff went bad (I have no idea why.... ) and it growled, sounded a bit like a tire rubbing.

 

[koda2000]

having just replaced all the bearings in the rear axle of my mountaineer last weekend, it had a gear 'whine', it was the pinion bearings. I read somewhere that carrier bearings 'growl' when failing, pinion bearings 'whine' and wheel bearing noise changes when you load up one side or the other in a turn. Parts to replace them all (carrier/pinion/wheel) in my truck cost about $200 including oil, to install them took me two days, and involved a lot of cussin' and stoppage for smoke/beer breaks. But it cured the noises from the back of my truck!

I had a Mustang Cobra a while back, the rear diff went bad (I have no idea why.... ) and it growled, sounded a bit like a tire rubbing.

It's definitely more of a growl, not a whine. It doesn't change during turns. So far it's sounding like it may be the carrier bearings. Do you have the torque specs for the caps? Where did you get your bearings from? Did you also get a spacer kit?

 

[jamie3529gq]

i bought the whole diff kit from Advance Auto. (timken bearings in the kit). Comes with spacers/shims, but I reused the factory spacers/shims, which is normally OK if not changing the gears. Pattern looked good to me when I painted the gears. (I pretended I knew what I was doing)

Torque specs are available all over the internet, if I remember right the cap bolts were 100ft/lbs. Lots of help on this forum too. I found one really good and very informative youtube video, if I can find it again I'll put the link here.

Worst part is getting the carrier bearings off, and tightening that dang pinion nut.

 

[koda2000]

i bought the whole diff kit from Advance Auto. (timken bearings in the kit). Comes with spacers/shims, but I reused the factory spacers/shims, which is normally OK if not changing the gears. Pattern looked good to me when I painted the gears. (I pretended I knew what I was doing)

Torque specs are available all over the internet, if I remember right the cap bolts were 100ft/lbs. Lots of help on this forum too. I found one really good and very informative youtube video, if I can find it again I'll put the link here.

Worst part is getting the carrier bearings off, and tightening that dang pinion nut.

I don't know what-all I'll need yet, but I saw this master kit on eBay:

http://www.ebay.com/itm/LINCOLN-MER...plorer+Sport+Trac&hash=item542002f19a&vxp=mtr

 

[jamie3529gq]

looks like the same type of kit I bought.

 

[SWIGIN]

I have done 25 or so 8.8 rears and I torque the cap bolts to 75ft/lb.

The rolling resistance of a 8.8 pinion with new bearings and seals I have found that 30-35 in/lb is the best.