I put a new 12 bolt in my 91 and I am experiencing gear wine. When I am on the gas the gears are singing and when I let off it goes away. I was told it needs to brake in. The rear end came already set up with Mohave gears and a Wavy posi. All I did is install the Wilwood brakes and fill with 80w90 straight gear oil. The instructions said don't use any additive or syn. oil.

I just don't like the noise. Will it go away? Am I using the rite oil?

 

That is a common complaint with 3.73. Some say they all do it, others say that only the ones not set up right do it.

It might go away but doubtful.

 

Mohave gears and a Wavy posi? I've never heard of those. Are you sure that's right?

No, the noise won't go away. A set of gears that makes noise almost always makes noise. I only know of one set of gears that made noise from the beginning that got any better after many miles were put on them. It's hard to find good quality gears anymore. China has caused all of the gear manufacturers to start cutting corners to compete with prices, so quality has suffered.

 

someone didnt build it properly sounds like.. it wont get better. pop the cover off post the wear pattern on the gears. someone can give you advice and have it rebuilt locally or try to warranty it. just a google search though proves trying to get anything warrantied through moser is a PITA

 

Did you follow proper break in procedure after you installed the new rear?

 

My moser 12 bolt whines between 40-45 and is quiet all other times. Same thing as you. If I let off the gas it goes away. But it's not very loud and tolerable.

 

I had a set of Richmond gears, the ring and pinon weren't a "matched" set or so the shop said, they couldn't ever get them to set right without wine. I sold them, bought a motive set and they went right in with no issues.