Noise in Newly Rebuilt 10 Bolt

**bdblevins** · 04-03-2013, 11:09 AM

I just rebuilt a rear end out o a 99 Z28 and put it in my 94 TA. I drove it about 3 miles and all is quite until deceleration then a terrible low pitch howling. A little history on the rear end. A friend took it out of his Z28 and installed a 9" Ford. It has a TrueTrac carrier and I put all new Timken Bearings, new Motive 4:10 Gears, a Solid Pinion Spacer, LPW Girdle with a Brace Kit. I'm pretty sure the Pinion depth is good and when I did the contact pattern it looked good. Everything was set up using Dial Indicators and Pinion depth gauges. Pinion was set to the proper preload and the nut loctited. I haven't went back into the rear yet but when I put it on my lift and rocked the wheels back and forth there seemed to be excessive play. Also my friend had 4:10 gears in the rear and it was noisy in his car to but it at that time was setup entirely wrong. Help, any would be appreciated.

**35th-ANV-SS** · 04-03-2013, 01:59 PM

You're going to have to pull the cover and inspect it. Anyone who tries to answer this would be guessing IMO.

If it is making noise though, it's set-up wrong - backlash, pinion depth, or an incorrect pre-load.

If the contact pattern has already been set, most likely there isn't anything you can do about it, aside from replacing it, or just dealing with the noise.

**bdblevins** · 04-03-2013, 03:15 PM

Originally Posted by 35th-ANV-SS

You're going to have to pull the cover and inspect it. Anyone who tries to answer this would be guessing IMO.

If it is making noise though, it's set-up wrong - backlash, pinion depth, or an incorrect pre-load.

If the contact pattern has already been set, most likely there isn't anything you can do about it, aside from replacing it, or just dealing with the noise.

Thanks, I'm hoping the pattern is not set yet being I didn't drive it but 3 miles at about 40 MPH.

**35th-ANV-SS** · 04-04-2013, 03:04 AM

You should be able to adjust it then - hopefully. Some brand/mfg of gears need to be set a little different than others due to design/tolerance from what I understand.

**pajeff02** · 04-04-2013, 03:33 AM

My Moser was stupid loud when I first installed it. Over time, things have quieted down considerably. Play it safe though and pull the cover.

**bdblevins** · 04-04-2013, 03:36 AM

Thanks, I will be pulling it in the next few days. It's not being driven so I maybe can wait.

**pajeff02** · 04-04-2013, 03:40 AM

With new gears, it isn't a bad idea to put the ass end up on jackstands and then run it for a few minutes in both drive and reverse. No real pressure on things that way and you can hear stuff a lot better... depending upon your exhaust note, of course. On TCS cars, you'll get a dash light but it'll go out of its own accord after you drive the car a bit.

**bdblevins** · 04-04-2013, 05:31 AM

Originally Posted by pajeff02

With new gears, it isn't a bad idea to put the ass end up on jackstands and then run it for a few minutes in both drive and reverse. No real pressure on things that way and you can hear stuff a lot better... depending upon your exhaust note, of course. On TCS cars, you'll get a dash light but it'll go out of its own accord after you drive the car a bit.

I ran it a few minutes and didn't hear anything but it was on my lift not jack stands. It is a four channel rear replacing a three channel. I'll put it on jack stands and see what I hear, that may make a difference with weight on the axle.
Thanks

**pajeff02** · 04-04-2013, 06:06 PM

How about your pinion angle? Did you check that?

**bdblevins** · 04-04-2013, 06:20 PM

Originally Posted by pajeff02

How about your pinion angle? Did you check that?

No, the only thing I checked about the pinion was pinion depth. How do I check pinion angle?
Thanks

**pajeff02** · 04-04-2013, 06:43 PM

Probably not the issue, unless you have adjustable suspension components, but doesn't hurt to check it as it can cause noise if improperly set: http://www.ls1.com/forums/f66/settin...n-angle-16320/

**bdblevins** · 04-04-2013, 07:29 PM

Originally Posted by pajeff02

Probably not the issue, unless you have adjustable suspension components, but doesn't hurt to check it as it can cause noise if improperly set: http://www.ls1.com/forums/f66/settin...n-angle-16320/

Thanks

**35th-ANV-SS** · 04-04-2013, 07:52 PM

I was going to suggest the same thing.

**pajeff02** · 04-06-2013, 04:29 AM

After I installed our 3 point SFC's, I forgot to check the pinion angle. As the center plates are inserted between the body and the tunnel mount bracket, it moved the front of my torque arm down by maybe 1/4" . I ended up with a growl on deceleration that immediately went away once I reset the pinion angle.

**bdblevins** · 04-06-2013, 06:39 AM

Originally Posted by pajeff02

After I installed our 3 point SFC's, I forgot to check the pinion angle. As the center plates are inserted between the body and the tunnel mount bracket, it moved the front of my torque arm down by maybe 1/4" . I ended up with a growl on deceleration that immediately went away once I reset the pinion angle.

The Torque Arm might have gotten bent or the bushing damaged I'll check them.
Thanks