just got 4.10's and a detroit Truetrac put in today. Ive been drivin around today and its been making a high pitched winding noise, sorta like a supercharger. Im wondering if its natural for a new rearend to make a small noise like that, it doesn't sound like anything serious but i wanted to get some opinions on this.

 

Some might argue with me but my installer had me 'break in my new gears. It shouldn't make any noise.

 

Sounds like the tolerances (backlash) are off. sounds too tight. ask him what they are, if he checked it he will know.

 

I would get them checked back out. You dont want to burn up that gear set.

 

I just had 410 gears put in Thursday in my truck and there is no noise. My friend is awesome doing gears. I would take the truck back to the installer sounds to me that he did not shimm the gears correctly. I would not drive it like that

 

I think it depends on the brand of gears. My AAM's made no noise.

 

I have 4.11yukons and trutrac, it made a very very small noise like that for about the first 80-100miles then it just went away??? now it is real quite, just like stock...

 

there motive gears. im definitely gonna take it back to him, i think the differential is locked up when turning also because one of the tires is barking....... a few other people i talked to said he didnt' space the shims right. I also gotta reprogram the PCM for the 4.10's, my speedo is way off and my abs and parking brake lights are on....

 

another question... is there a special type of oil/lube that should be put into the gears????

 

I would take it back to the installer. I had my Tru Trac and GM 4.10s installed and made no noise at all. My abs light was on, and speedo were way off too. Pcm tune will take care of it. As for fluid my installer highly recommended Valvoline for fluid. He does ton of rearend builds and used to use Redline fluid . He would do a yearly check out of the rearends for the dirt track cars and drag cars and they showed alot of wear when using the redline. He switched to valvoline and now on the yearly check outs , there is no sign of wear. So he told me just to use Regular Valvoline and it will be fine. A few of my buddys that he built there rearends are using the Valvoline fluid and no wear. These cars are raced and driven on the street.