I have been having some rear end problems with my new 12 bolt recently. I had to take it to a strange dealership to get it fixed under warranty. What strange told me is that the 3.91 gear set tends to make a lot of whining noise at certain speeds. This really sucks I think, and they said they could either swap out a new 3.73 gear set or 4.10. I want this car for street/strip. I like the 3.90 gear set. I am asking you guys which gear set should i go for the 3.73 or the 4.10, and how much of a difference would that make from my 3.90's

 

Be sure to check the brand name of the gears and find out where they are made. The new US Gear 3.73 sets are made in China and make a lot of noise. All of the stuff coming from China is junk and should be avoided. Motive Gear is the only one that I know of right now that is any good, unless you can find an older US Gear 3.73 that was made in the US.

 

When they ordered a new gear set it was 1/4 inch narrower. So I would of needed a 1/4 inch spacer. It looked like a cheap gear set, and of course it was made in china. What is going on anymore with crap being made in china!!! I have not figured which set to go with yet?

 

theres only a 200 rpm increase between 3.90's and 4.10's. what are you using the car for? if its mostly street driving then 3.73's, 4.10's for the track. also i have had no luck with US gears. sheared the teeth off a couple sets and they were noisy. im using richmond racing gears now. the guy at the speed shop i go to said there is a big difference between regular richmond gears and the race gears. these are still street gears, not pro gears.

 

I'll tell you why we are getting all of this crap from China. Too many people are looking for the cheapest price instead of better quality. We are willing to sell ourselves out just to save a few dollars and our economy and quality of products are showing it. If people quit buying this crap there wouldn't be anymore of it. A lot of the stuff that Summit and Jeg's are selling is made in China, and they are selling it because it is a few dollars cheaper than the better quality US made parts. I don't know how many people I have seen buying the "made in China" axles, gears, bearings and other parts from Summit, Randy's Ring & pinion, Jeg's and others, instead of the parts from Moser, Tom's Differentials and others that cary the better quality stuff. US Gear is made in China now because they couldn't compete with the cheap junk coming from China. Moser is trying to change over from US Gear to Moser right now becauise they got a bunch of US Gear stuff that is made in China and it's causing them a lot of problems. Pisses me off!