greenfbodyracer

iTrader: (16)

Well I have a ls1 A4 with an 4.10 in the rear.. when the car is slowing down I get this humming/sceeeching noise like crazy loud and some times it wont be as loud.. But I think it is the rear end and not the trans because I just built the rear end up and I probally forgot something, the backlash is perfect, all the shims are good, Brand new bearings except the ones at the end of the axle closest to the brakes, I am thinking that it is a bent axle shaft.. Or I might not have enough fluid it there. How many quarts does an 10 bolt take??? I thought 4??

Thanks

Greenfbodyracer

mzoomora

iTrader: (36)

About 2 quarts of fluid, just a little shy.
I would check you bearing preload (pinion and carrier) and also backlash first.

scof0elife

iTrader: (4)

Yeah, mine is whining also and I believe its the backlash. Just don't know how to go about fixing it.

keliente

iTrader: (22)

So your backlash was right but what about your pinion depth and gear pattern?

greenfbodyracer

iTrader: (16)

well I havent drove it far, mabje 3-5 miles, I dont know if it needs to be broken in more or not, but I guess that I will take it all apart tomorrow and look at the backlash again...

keliente

iTrader: (22)

Backlash is only half of the equation. You need to get some gear paint and see what the contact pattern looks like. It will NOT get quieter by breaking it in.

greenfbodyracer

iTrader: (16)

well I did do the gear paint and saw that the gear pattern was right where it needed to be, But I put my car on jack stands in my garage just now, and saw the problem,, it is it pinion where it connects to the driveshaft, (yoke???) it is loose, What is the proper torque for that nut? because that has to be the problem it shouldn't be moving that much.. I would try to fix it tonight but I dont have the proper tools to do it at home...

mzoomora

iTrader: (36)

That would be your pinion bearing preload. The two main causes of decel noise are improper backlash and improper bearing preload. There is no torque for that nut, you need to start with a new crush sleeve and tighten it until you have about 25 in/lbs rotational resistance with new bearings (which if you just did a rebuild I would hope you changed). Go slowly, because it comes up fast.