Hey, I did a little searching but wanted to get a little input. About 2 months ago I had a Truetrac swapped in my 7.5 open diff and it seemed pretty quiet when I got it back. Recently I seem to get a consistent whining at about 20-35 mph, regardless if I'm accelerating, slowing down, in gear or neutral. It also changes pitch as I go through that speed range. Outside that range it's completely quiet again. It's hard for me to directly pinpoint if it's coming from the back or front of the truck because I recently had the local dealer re-pack my front wheel bearings, and I can't tell if maybe they messed something up or what..

Other than me trying to just listen again which direction the sound is actually coming from, does anybody have some other advice on this? I'm kind of scared because I'm assuming that the differential guy put in whatever friction related fluid for the L/S, but I guess I'm not sure if that's common knowledge...

 

First thing I would do is check the fluid.

 

Thanks, I'll prob do that pretty quick.