tony

What is causing the whine associated with the 11.5"? Several people are reporting this problem and some have it "fixed". What was found to be the problem? Pinion depth, backlash, gear set defect, machining errors in the housing etc.? Has DC officially acknowledged the problem?

I have a whine in my 3.73 with the anti-spin; build date is 10/03. The noise is slightly noticeable under power between 45-55mph and very pronounced coasting at all speeds. I'm reluctant to let the dealer try a fix without some recognition from DC that there is indeed a widespread problem.

From what I understand, the Duramax uses the same rear, and the Duramax web forums rarely mention any issues with the 11.5"AAM. Could the whine be coming from the differential? The Duramax uses an Eaton Gov-lok, while the Rams use the AAM TracRiteªGT.
Thanks!

BDude555

I've got a 2004 2WD Dually with the 4.10 limited slip rear in it. the whine started at about 3400 miles. I checked the fluid level and found it about an inch below the fill whole (probably over a pint low!). My first guess what might cause this is that when the trucks are on the assy. line they are sitting level, once its off the frame supports and on its wheels it sits WAY high in the back, probably a 10-15 degree difference on a 2WD (less on the 4X4). so I would think the shaft bearings are being starved for oil while the pinion is flooded over. GET IT LOOKED AT SOON!

tony

When I had about 175 miles I checked the fluid level. The level was even with the mark on the cover.

J&L

Tony------my truck has a 3-03 build date . At 6000 mi I noticed whine getting loud. I added 1 qt to bring it to bottom of fill hole. Whine is very noticable around 65 mph with R and P gear in float condition. Took it to dealer last fall and they could'nt hear anything. When its cold in mornings whine nearly goes away so was wondering if 85w-140 syn. would help? My dealer is in small town and i doubt if they have mec i would trust working on a r and p gear. I'll watch your thread for more info. Sorry didn't have any answers.---------JIM

rossn2

Only switch to the 75-140w if you do alot of heavy towing. Other than that truck comes from the factory, albeit underfilled, with 75-90w synthetic. The 3.73 is the problem, the factory didn't seat the ring/pinion correctly and that's why the noise is developing. AAM already has a replacement ring/pinion out. Or you can get a whole new assembly under warranty.

If you don't want the dealer working on it, you can always try changing the rear/frt end out to a better synthetic. You can run AMSOIL Series 2000 75-90w or REDLINE Products and it'll get quieter. The covers have reuseable rubber gaskets. All you have to do it crawl under the truck and take them off, and refill with the new stuff.

BTW, The Body sits at an angle to provide better fuel mileage and it has nothing to do with the frt and rear meatballs not sitting level.

Good luck

BDude555

Took my truck into the dealer and when they removed the rear cover we could see that the fluid (even though a full inch below the fill hole!) was still covering the bearings, I cleaned about 2 tsp's of stinky, thick, metalic, black sludge off the magnetic fill plug before driving it to the dealership, when I got there the service guy wiped out the rear end with a white glove and found absolutely nothing else in there. he refilled the rear end and out we went for a test drive. no noise now!
We both inspected everything as close as we could and didnt find anyplace the goo might have come from, gears, diff., and bearings looked like they were never even used as far as we could tell.
Sevice guy really impressed me with the fact that he wanted to do what was best for the customer. YOU'LL NEVER SEE THAT AT AN CHEVY DEALERSHIP, OR EVEN WHEN THEY BLOW YOU OFF AND YOU CALL GM DIRECTLY!!!
BUY DODGE!

TurboTed

Dude- What year's your truck? Gear ratio...?

BDude555

I've got an 04 HO Dually, 4.10 limited slip, 6 speed, 2WD
The metalic goo has still got me worried, the noise is gone and all looked well when we inspected the rear end, but that stuff came from somewhere! Glad this thing has a long warranty, I dont mind doing the work, but PARTS AINT CHEAP!

blownaway

I have a 2003 3500 4x4 3:73 and mine has that howl at 20-30 accel and decel, More so when cold it seems. I heard someone make ref. to it as a ghostly howl or something , well that is what I have too. 11500 mi. I thought it was the rearend but don't know for sure. I also have a 48RE which made me wonder if it was the planetaries making noise.