transmaro93

iTrader: (4)

long story short iv put a number of miles on the car including one 4 hour round trip and the rear never made any noise. I bought it used with supposedly no runs on it and only about 2k on it. I went to the track this past week and put only 3 runs on it and only launched it at 4k with a t56 and on the way home it was whinning really really loud on accell and kinda of medium on just light throttle and on decel is almost sounds like a growl... i took the cover off today and there wasnt any crazy metal in there or anything just wondering if anybody has any input.. im going to check the back lash next week after i score a dial indicator. the car ran fine on the way home it was jsut really really noisy. Not a normal low gear whine its pretty loud... just for some backround its a strange 12 bolt with 33 spline axles and eaton posi 4.11 gears...

Bob@BruteSpeed

iTrader: (16)

https://www.brutespeed.com/rear_end_information.htm

See the link above that I created regarding 12 bolts and noise. Bob

transmaro93

iTrader: (4)

thanks thats very helpful

BIG BAD BLACKSS

iTrader: (4)

The strange 12 bolt in my car has gone 1.29 60's on a 12 bolt and is quiet. Cars under 3000 lbs and has a th350 and loose converter though.

Troy

iTrader: (10)

Did you check the backlash? I'd be surprised if it didn't increase and lead to your increased gear noise.

6spd97ta

iTrader: (2)

Welcome to the club !!! Paid 28xx for this pile brand new. Same senario as you. First time after the track it was loud and now its to the point I don't like driving the car its so loud. Not to mention I have about 100lbs of dynomat covering my floor doors and trunk well for my system.

ss1

iTrader: (32)

I had the exact same thing happen with my Strange 12-bolt. When I pulled it apart to install new gears I checked the the pinion depth and backlash, they were on the money. The article Bob posted the link to gives a great explanation.

Supers

If the housing is distorting, then it would make sense to make a mount to move the tq arm to the tube

But.... I would imagine the pinion is loosening up

Has anyone ever fully checked to see if anything has changed....

When you guy's launch these things at 5k and some at 6k... you are hammering the **** out of the pinion....and if you are using a crush sleeve...... YOU very well stand the chance launching like that at changing it's preload..

Yes i know all about the tq arm...and if anything it helps transmit/amplify noise thru the car...

There is more to diffs then backlash...sometimes just polishing the ring teeth at the top make all the difference.. However

I would be concerned with looking at the preload....

The noise you are describing is that of a loose pinion, or bad bearing, and you aren't going to find a bad bearing by looking...and if you do then the R&P are hammered