I had a shop set up my new 3.73 gears on my gm 10 bolt and they gave me a few pictures of the pattern. They are telling me the whine is normal. I asked for a competition contact pattern. I don’t know much about gear patterns. What does everyone think about the pattern? Is it set up wrong or do I have another issue causing the noise?

Coast side

Drive side

posi is Yukon duragrip
gears are us gear 3.73
they used 80w90 standard gear oil and trans x limited slip additive

 

Pattern looks OK to me.

Whine is more likely to be the bearings. Not enough or too much preload. (probably, not enough) When is it worst; in drive, coast, or float?

 

I’ll have to drive it again to confirm but I believe it is only noticeable during coasting.

 

It is most noticeable coasting from 50mph down. There might be a slight wine when cruising at 50mph but I can’t differentiate that between road noise. The rear end only has about 25 miles on it.

I’m also getting a rubbing noise from maybe the posi when doing tight corners. I read on here that maybe I should get some more of that friction modifier. They said they used half a bottle of trans x which looks correct from what I read. (Whole container is for 4 quarts)

 

Pattern looks fine. Most of the numerically higher ratio gears will have a note in the instructions that say they will make some noise.
I have 4.10s and I used a special wheel in a Dremel to deburr the edges of every single tooth both ring and pinion gears.
I have no noise.