I got my new 4.56 gears and detroit true trac installed this weekend. It wasn't easy, but I got it done. Then I realized just before putting the rear differential cover on, that I forgot to install the tone ring for the speed/ABS sensor in the ring gear. I felt the biggest dumb ***. For now I decided to leave it that way until I get some more time to tear it apart again. So the maiden drive showed some signs of something not right. On decel the rear has a whine, but goes away on accel. I know there are some gear brands out there that have a natural noise even when the gears are set up perfectly. What brands are those? I know Yukon says their gears are quiet. The brand I bought from 4wheelparts.com are "genuine gear". Any comments on this? Please tell me that someone else has forgot to install the sensor ring...

 

There will be some whine but it can be mostly adjusted out with backlash. How much play is in your pinion yoke? Is there any rattle or chatter coming from the gears? These are an indication of impropere backlash settings

Vibration at higher highway speeds? I'm still working on that one myself.....

 

I don't have any vibration at any speeds, except what might be caused from my new tires, which should be taken care of this week after an alignment. I talked to the to a friend I worked with at the dealership and he thinks I might have the pinion in too far. If it is, it is only slight, but I will most likely take it apart again if for nothing else than to install the tone ring for the speed sensor. There was only a slight drag on the pinion and 15-20 in lb of turning torque which were both directed in the service manual. There is no rattles or chatter, just a higher pitch whine on decel at speeds above 30mph.

 

Backlash is not set right... Whining on the coast side or the drive side is most always a backlash setting. They are pretty sensitive to that...

 

What size tires are you running?