to me just sounds like you didn't get the pinion bearing set right. i hate doing gears.

 

Hello Gents...

I just tore down my 9.25 trac-loc diff to replace some of those dreaded clutch pack clips... they were coming apart and on their way to destroying this diff for good.... I believe I caught it in time. Anyway..... I just got it all back together yesterday and while testing it on the road today for about 100 miles.... I experienced the exact same thing.... perfectly quiet on the acceleration... but howling on the deceleration. There is also what sounds like a bearing noise (grinding) at certain axel shaft rpms. Suspected the pinion bearing. When I tore this thing down I did not mess with the pinion gear at all except turning it to inspect it.. and dousing the pinion gear oil sump to see if the drain was ok.... all seemed ok so I didnt mess with it. Now this noise. Could it be a bad bearing... or was I supposed to torque this pinion nut to some spec before reassembling. It spun freely when I was inspecting it. 2002 Ram 1500 4X4 4.7L

 

Ref my post above..... After doing some searching and reading.... it really sounds like while I had this thing apart I should have redone the bearings and made sure the pinion preload was correct. Guess I'll have to take it apart again to get it right. Live and learn.