Rear differential problem

[Eric Ellis]

Going to pull my rear nose cone today I think.

Seems to be some stiffness at points in turning the shaft. It is not the shaft and from the back the ring gear etc. look good. Question is what bearing (s) is it likely to be?

There is now scratching in motion but when driving and rolling in nuetral to a stop you get a rumble that sounds like a flat or a wheel about to fall off. You can not really simulate the sound too much up on stands...maybe a little.

any ideas?

 

[Bret]

You could pull the diff cover off and take out the rear axles and maybe get a better idea if it is the diff. You will have to pull them anyway if you drop the third. The pinion bearings are the hardest to get to, but likely your problem.

Since you have to take it apart anyway you can check the wheel bearings etc. and such as you go. When you get to the pinion bearing you will have checked everything else before you got there.

Nothing on the magnetic drain plug or in the oil?

 

[terrx]

Have you checked that the nut on the front pinon hasn't loosened up? That and/or a failure of the pinion bearings would fit what you describe. I'm thinking that on jack stands the two wheels will rotate (opposite directions) while the pinion is stationary so you wouldn't notice it.

 

[Eric Ellis]

Thx guys. Yeah the drain plug was clean and I found nothing in the oil which was clear still...think I just did the rear axle seals about 6 months ago. Front stake nut is on like a rock. in fact, getting the drive shaft bolts off was tough--everything in the front was way tight.

 

[Pin_Head]

There is now scratching in motion but when driving and rolling in nuetral to a stop you get a rumble that sounds like a flat or a wheel about to fall off. You can not really simulate the sound too much up on stands...maybe a little.

any ideas?

Noises are notoriously hard to diagnose without actually listening to them, but if the noise goes away when you take the weight off the wheels, I would suspect an axle bearing. If something was really wrong with the differential, you would expect to find metal flakes on the drain magnet. You would also expect to get flakes from a bad axle bearing.

 

[Eric Ellis]

TX. Have not gotten to it yet and will back off an take my time looking at it since it will now be next weekend.

 

[Pin_Head]

Do the easy things first, like check the brakes for dragging and rubbing. I have been fooled before thinking that a noise was a bad bearing to find out it was my brakes.