Last week I noticed a funny noise coming from the back somewere. Mainly when I am going around 25mph. It sounds like I have big swamper tires on my truck. Axle bearings? Ring and Pinion gone? I put in a new Spicer Ujoint 1 month ago. Its a 99 1500 360 2wd Open diff, 1.5 year old rebuilt tranny. I have changed the fluid and filter 5k ago. the truck has 158k on her.

 

9.25 rear ends have been known to have issues, are you sure the noise is going away after 25mph or is the pitch just getting higher where you can't here it? The only true way to tell is to lift the rear end and physicly check it. Ussually if the pinion bearing goes bad you can hear it at any speed as long as there is a load applied. It could be a bad axle bearing if youhavea road that you can take a 25mph turn on take it and see if the noise goes away, then you can tell what sideis bad. From what I remember it is the carrier bearings dodge had a problem with and the shims that held them in place they would wear and make that noise but usually it hapened at any speed. When you put the new u-jointin did you loosen it?You do that by taping onthe yolk with a hammeron all four sides. If the u-joint was tight I have seen them go bad within as little time as a week. Good luck

 

Loosen the U joint? I have never heard of such a thing. please elaborite. I pressed out the old an pressed in the new (on the drive shaft) and just used the little "C" brackets to bolt it back to the rear end. Hmmmmmm

 

If the noise is already there
there is not much you can do
except try to re-torque the big nut
to put the proper 'pre-load' on the pinion bearings
but if it were my differential
I would bite the bullet
and get the differential bearings & seals changed out to new.