Okay....my father and I are restoring an 89 formula 350 that came with 3.27s. The unit went bad so we decided to buy a new unit from diff solutions. We put the 3.70s in and noticed a loud whine.....okay back to the garage....we bring in a gm mechanic(father's friend)...check the tolerances ...backlash...ect...put it back together drive it down the road....now a slight whine has decided to rear its ugly face....any suggestions............all help is appreciated....thanks guys...

 

Most all Aftermarket gears will whine. Some louder than others (Richmond) is the loudest I've ever owned. Even factory will whine, but not as load as aftermarket.

 

thanks......this is the borg warner 9 bolt.... ...so do you think we should leave for the time being?

 

well as long as the teeth are contacting the pinion teeth right, then it should be fine. like said, all gears whine a bit.

 

Once a wear pattern is established, you will never get rid of gear whine no matter how much you adjust it.

A tiny bit of whine is ok. Loud is not tho. The whine is also a vibration and will destroy the gears in the long term.

 

Most 3.70's (after market) tell you right on the box they are noisey. Us Gear, Yukon, Precision Gear and others.
I think they all buy from the same place and rebox them (9 bolts)

 

I had 3.70's in my car, they were professionally installed in the 9 bolt and they whined alot. Don't worry about it man. They all do it.

 

Thanks guys.....my old man was all fired up about it....we've got some good money in this formula 350(white G92 ws6 with t-tops) eventually we'll get some pics going.....