Drivetrain Whine: Is it bad and where is it coming from?

[xj220]

After I did my suspension upgrades (including FAB9 rear end with 9" TrueTrac, 3.70 gears), I've been having a whine that develops above 45 mph or so. When I press the clutch in, the noise goes away (about 32s in the video). Here's a clip for reference:


https://youtu.be/2VE7LIwFfy8


The interior is out right now, but even with it in I still noticed the sound. I've never had transmission issues and it was just fine before it went into the shop. Thanks in advance.

[Z06vet]

Who set the gears up? Sounds like gear whine to me.

[xj220]

It was purchased as an entire unit from Strange Engineering and installed by a shop.

[Z06vet]

I went thru this a few years back with a brand new complete moser 12 bolt. Worst gear whine I had ever experienced. The setup was way off. They sent me new gears but I had to have them installed on my dime. Its hard to say for sure from a video. Maybe pull the center section and have the pattern checked for proper setup.

[xj220]

Well they're under warranty but I'd have to remove the unit and send it back to them (in Illinois). At that point, I almost wonder if it's worth it to pay a show to pull the unit and check the lash and pinion angle. Just frustrating.

[parsonsj]

Aftermarket gears, I'm guessing?

They whine. They all whine. If you want a quiet rear end, you need to use factory gears. From now on, I'm only using 8.8 Ford rears, because I can get new Ford gear sets that don't whine.

The whine is only a noise.. there's no harm in that. No accelerated wear or anything. Just a whine, and if doesn't make you insane, I'd leave it be.

https://www.pro-touring.com/threads/116511-New-moser-or-build-an-original-12-bolt?highlight=gear+whine+parsonsj

[xj220]

Yeah, they're aftermarket. I keep hearing different things though, the whine is normal, it isn't, etc. There doesn't seem to be a straight answer.