I had my truck regeared to 4.56 3000 miles ago and everythings been good untill recently. I've been getting weird noises from the rearend.

At just under 20 mph when I'm decelerating or light acceleration at any speed it makes a sound like one of those old crank style sirens getting spun slow (seen somebody describe like you said wow a bunch of times). Most people I've read about with the same symptoms turned out to be the rear bearings.

I'm not sure thats the case with mine. After some reading I put'er in neutral while it was making the noise and turned the key off and the noise completely stops. I can coast to a complete stop and hear nothing.

I'm not sure if the noise is related to having the gears done or if its cause I have 210000 miles on the truck and things wear out.

any ideas?

 

Take it back to where you had the gears done, and let them have a listen to it. Sounds like something moved, that shouldn't have.... and clearances aren't quite right any more.

Check fluid level right away though....

 

Should have mentioned that I changed the gear lube the other day to a thicker 75-140 and it didn't change anything. Also, It seems to be louder once everything gets warmed up.

I did talk to the guy who did the gear change this morning and will be swinging it by there tomorrow so he can check it out.

 

turns out it is the gears and the mechanic is gonna replace them next week