I am having trouble getting my gears to run quiet. It is a 92 Camaro with a 7.5 rear. The gears are new 3.42 ratio Yukon gears. I have tried 10+ times, changing shims on the pinion and setting backlash. I have attached a couple photos of the drive and coast patterns. They seemed pretty good to me. This is the current pattern and it whines above 45 to about 60. Seems to get quieter over 60. Prior to this setup I had the same whine and I took out .002 from the pinion shim to get to this setup. Backlash is at .008. The pinion is at .037; it was at .039. The ring side pack on the carrier is at .210 and the right side pack is at .265. The guys at Yukon said the pattern looks good and "The gear noise that you hear at 45 – 60 is a characteristic of an aftermarket gear." I can't just live with it. Any suggestions?

 

Here is the coast side

 

Aftermarket gears are harder than factory, thus tend to be a bit louder

 

Looks like your pinion is a little too deep. Backlash looks good to me. If you can't get them quiet enough you may want to try a good used set of OEM GM gears. I've ran two sets of used gears and they've been silent, even with unperfect setups.

 

Pinion is a little deep. I'd remove about .002 or .003 from the pinion shim. Check your papers and see what the recommended backlash is. Yukon gears use a little more backlash than some other brands.


If this doesn't make it better then you are going to have to try another set of gears. Sometimes a gear is just going to make noise no matter how well you set it up. I've installed hundreds of Yukon gears and I've had to send a few back because they made noise no matter how I set them up.


You may have a hard time returning them. Even though I had my own rear end shop and was buying a lot of Yukon parts they would still argue with me about a gear that made noise. I guess they treat everyone like they don't know how to set up gears, even though they knew I had been doing this for more than 30 years.

 

I appreciate the feedback. I will try going to a .034 or .035 shim which should make it perfect and hope for the best so far as the noise goes. I haven't asked about a return but I did not get a warm and fuzzy feeling from the manufacturer. I've called twice and emailed twice and only got one short reply so far. Waiting for them to get back to me regarding some additional questions I had. Maybe I was mistaken, but I thought Yukon was about the best out there. I didn't buy the cheapest gears and was hoping for a bit of a better result.

 

I took .002 out of the Pinion shim. It is at .035 now with the backlash at .008. It is definately quieter. Not silent, but I can live with it now. Hoping once it wears a bit it will get quieter. Time will tell. Thanks for the suggestions.

 

 

I run 85-140 gear oil in my 10 bolt. You bet its quiet.