JimMueller

iTrader: (9)

I knew already had a slow leak from what appeared to be the pinion seal, and had just minor noise coming from the rear end while driving normally. There were never any significant drips on the pavement, maybe only a quarter-sized once in awhile.

I was out datalogging tonight and it seemed in my efforts to hit all the cells in the table some of my engine decel actions caused much more decel whine to develop. At a stop, and when I got home, I did notice a bit of hydraulic odor around the car.

I read in another thread that decel whine is caused by the gears. What are the chances I'm looking at an inexpensive vs. expensive repair? The whole shebang was went through by a local reputable gear installer, hmm, last November I think. I don't know if they did anything with the pinion seal though.

Bob@BruteSpeed

iTrader: (16)

Check the rears fluid level, add fluid if it is low and keep an eye on it. These rears are too small for the power these cars put out, and you can expect to pick up gear noise.
https://www.brutespeed.com/rear_end_information.htm Bob

JimMueller

iTrader: (9)

How low on fluid would it need to be to cause decel whine?

Jawsgear

iTrader: (2)

Adding fluid will not stop any noise and if it is making noise you dont want to ignore it. Seal Leaking is a sign of bad bearings in the differential. I would love to sell you a 9" like the rest but reality is not everyone has $2500.00 + to throw at a car for an upgrade. You can easily change the gears and bearings for about $350.00 or so if the gear is even needed.

Jeff

JimMueller

iTrader: (9)

I spoke with the owner of the local shop that did the gear install on 11/16/09. They said they offer 12mo/12K warranty on their work. Earliest they can get it in is next Tuesday morning. There's no way I could have put 12K miles on the car since November, especially with the car being down for 2 months for the engine repair. The pinion seal would last have been included with their DTC master install kit, and they'll handle that as well.

You say leaking seal is a result of bad bearings... what causes the bearings to go bad?

Don't want a 12-bolt or 9". Combination of cost, weight, and having inadequate posi options for a car designed for autox/RR.

JimMueller

iTrader: (9)

Long story short, the place that installed everything last November honored the 12mo/12K warranty. They said the power side of the gears looked new and the Eaton CF posi was fine, but the cruise side had all sorts of hot spots. He said that's very unusual... usually a result of strong engine decel. He said if I had broken gears then he wouldn't have warranted it, but this is the first and only time they'll warranty it after seeing the suspension underneath and hearing the built LS3 motor. They originally only asked if I drag raced it, and I honestly answered no. The car was towed to their shop last November when I damaged something at the autocross, then it was daily driven through mid-April, then the car was down until mid-June. Only about 3K miles since November for a daily driver as a result.

Well, that's what it amounted to to log those VE cells. Reviewing the log, I went to 5500 and then let off the throttle completely for 10s, 5400 and off for 12s, then to 6700 and off for 25s, and those were the only real high RPM decel I logged. Could this little of time on hard engine decel caused the problem? Could there be other factors in my daily driving such as rev-matching coming to a stop instead of just using the brakes (I would think that'd be more harm to the tranny than the rear-end), etc which I need to consider altering?

They tried to convince me to consider a 12-bolt or 9-inch, but even if the price wasn't outrageous, how much heavier are they than the stock rear-end, and are there autox/RR-type diffs available for them? I think I've read some 12-bolt owners don't fix their problems until they buy a 9-inch.