Rearend noise

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DARTLARRY

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Have an 8 3/4 suregrip makes no noise under acceleration, when i let off of the accelerator it makes a whining bearing sound. I am trying to pin point the area, wheel bearings look fine, could it be a differential bearing? How hard is this to replace?
 
Have an 8 3/4 suregrip makes no noise under acceleration, when i let off of the accelerator it makes a whining bearing sound. I am trying to pin point the area, wheel bearings look fine, could it be a differential bearing? How hard is this to replace?
Outer pinion bearing. Stop driving it.
Get under and check the yolks nut is tight.. itll will send the pinion gear into the carrier if it gets real loose. More than likely you'll need to pull the axles out a hair and drop the center pumpkin out to inspect and replace bearings.
 
Is this a new to you or new set/fresh set up it could be set up wrong as in the shim/crush sleeve etc or if this has been something thats been ok and now doing this maybe a pinion bearing or maybe pinion nut loose
 
A dumb question, have you added the 4 oz. friction modifier additive yet? I did not add it and the carrier made noise until I did
 
Probably why he sold it to you. Who ever installed it didn't check it before they put it in. The sure grip additive won't correct a ring and pinion misalignment. Hope you didn't pay that much for it.

When ever you buy used parts know what you are looking at . Hopefully it just needs bearings and to be set up correctly. What carrier is it 489- 742 or 741
 
I cant fathom paying what most people ask for a used chunk ! No way I am paying 75%+ of new retail for a mystery punkin. Unless I know and trust the seller.
 
it makes a whining bearing sound

Possibly a gear set with lots of miles on it, or if new, not set up correctly.
If you really want to know, pull the pumpkin and check the mesh pattern and gear lash.
also do a visual on the gear wear pattern.

On a used center section I would always check the lash and mesh pattern prior to purchase.
 
Have an 8 3/4 suregrip makes no noise under acceleration, when i let off of the accelerator it makes a whining bearing sound. I am trying to pin point the area, wheel bearings look fine, could it be a differential bearing? How hard is this to replace?
I had some noise coming from my rear end earlier but I am OK know. LOL
 
I would just drop the drive shaft and inspect the pinion nut closely. They are bad about backing off. That could be all it is.
 
Outer pinion bearing. Stop driving it.
Get under and check the yolks nut is tight.. itll will send the pinion gear into the carrier if it gets real loose. More than likely you'll need to pull the axles out a hair and drop the center pumpkin out to inspect and replace bearings.
and if its doing this and you get on it, the u-joint is the weak link that brakes when pinion binds up against the carrier!!!! i snapped 3 u-joints in my duster the 1st weekend i got it because of pinion nut backed off! tighten'd nut up 2 times it kept getting lose, 3rd time it got the seal so i went threw it and did the bearing seal crush sleeve and new locking nut! then spot welded the sob! 9 years of no more issues with it!! had new joint in it already,probably one the reasons it was for sale so cheap!
 
It's probably pinion preload, or lack of it. What you are hearing is the early stages of self destruct mode. Once the pinion is allowed to run misaligned the gear set is pretty much garbage. If you replace the pinion bearings and set the preload correctly you might (and it's a big maybe) get an acceptable pattern and reasonable lash. They will most likely still be a little noisy. Once gears get noisy the only way to make them quiet is new gears. As others have said, the pinion can hit the carrier. This just fills the axle housing with shrapnel that will destroy everything in short order. I just spent 2 hours under a Chevy truck cleaning the metal gunk out of a 12-bolt housing because this happened.
 
Pulled the driveshaft, pinion nut is tight. But there is a lot of play in the in the axle when I turn the pinion. Should there be that much play back and forth?
 
Pulled the driveshaft, pinion nut is tight. But there is a lot of play in the in the axle when I turn the pinion. Should there be that much play back and forth?
nope! thats slop in your gear mesh!! or wallowed out axle shafts! my money on ring n pinion ate up!
 
I will pull the center section an inspect it, it looks like one of my winter projects may be to install a new ring and pinion.
 
update-

I had the drive shortened, and balanced. The noise that I blamed on the rear end went away, it must have been the driveshaft.
 
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