3.91 Gear Whine During Deceleration - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

2010BlackCamaroSS · 01-30-2022, 05:45 PM

I've got about 100 miles on the new AAM 3.91 gears and I am experiencing some gear whine that happens consistently from 48 mph to 40 mph. No whine at any other speeds during acceleration or deceleration.

I'm looking for some experts to chime in. Should I be worried?

Thanks, guys.

SaReNi · 01-31-2022, 02:49 PM

who did the job?

oldman14ss · 02-06-2022, 08:01 PM

don't want to be the bearer of bad news. they shouldn't whine no matter what speed or milage on them. its not the gears it was the install. poor install cost me 1500 bucks and a new set of gears I have AAM 3:70 gears on a Detroit tru trac. first install sounded just like yours. was going to take mine back to the same dude but why? so he could screw it up again. I apologize but I think you have problems. I hope you don't I went 1 gear oil change and 2000 miles and all it did was get worse. took it to a guy nwho knew what he was doing no whine straight out of the box 10k miles still no noise what so ever

shibbs · 02-06-2022, 09:48 PM

Yep. Noise = improper install. Gears are helical cut to avoid noises, so any noise means it's too late.

WVracer · 02-07-2022, 01:08 AM

Sounds like backlash or bearing preload wasn't done properly. Bearing Preload is the one most people neglect. If the preload isn't right it will cause the gears to shift which will then cause improper set-up and create noise. I'd take it to someone and have them double check everything.

oldman14ss · 02-10-2022, 08:04 PM

tolerance on my pinion was so tight that it didn't need shims.

2010BlackCamaroSS · 02-11-2022, 07:24 PM

Thanks for all the replies, fellas. I know I have read several times that they shouldn't make noise. If it makes a difference, I did upgrade the diff bushings and installed an LPW cover. I hear that can increase NVH.

I knew the 1st shop I took the gears to did a horrible install job; it was clear from the gear pattern and the ratcheting sound the diff made when rotating the pinion. Luckily, they admitted they couldn't do the job properly and didn't charge me any money. However, they gouged up my case pretty bad, so I'm going to have to bill them for the damage.

I decided I didn't want to take a chance on another shop that I didn't know anything about, so, for piece of mind, I took it to a shop that has a great reputation on this site. If they can't get it right, I don't know what else to do.

I have been babying the gears (which is excruciating) so that they are broken in properly, but it sounds like I've been wasting my time.

01-30-2022, 05:45 PM	#1
2010BlackCamaroSS Drives: 2010 Camaro 2SS/RS - L99 Join Date: Jun 2021 Location: MS Posts: 128 View My Garage	3.91 Gear Whine During Deceleration I've got about 100 miles on the new AAM 3.91 gears and I am experiencing some gear whine that happens consistently from 48 mph to 40 mph. No whine at any other speeds during acceleration or deceleration. I'm looking for some experts to chime in. Should I be worried? Thanks, guys.

01-31-2022, 02:49 PM	#2
SaReNi Drives: 2012 SS Join Date: Dec 2021 Location: Florida Posts: 406	who did the job? __________________ 2012 Camaro SS

02-07-2022, 01:08 AM	#5
WVracer Drives: '11 2SS/RS LS3 M6 (Sold) Join Date: Dec 2015 Location: VA Posts: 200	Sounds like backlash or bearing preload wasn't done properly. Bearing Preload is the one most people neglect. If the preload isn't right it will cause the gears to shift which will then cause improper set-up and create noise. I'd take it to someone and have them double check everything. __________________ 2011 IOM 2SS/RS LS3 M6- Injen CAI, TSP 1 7/8” headers, PTB, Hurst short throw, Corsa catback exhaust, 20" TSW Nurburgrings, BMR lower control arms, BMR tunnel brace, Hotchkis lowering springs. 3660lbs. Tuned by me (sold) 2010 RJT 1SS/RS LS3 M6- CAI, TSP 2” headers, TSP F-35 cam, PTB, Hurst short throw, Dronemaster catback, BMR lowering springs, Kirkey seats, 20”/18” Weld Belmonts, 3550lbs.

02-06-2022, 08:01 PM	#3
oldman14ss Drives: 2014 1ss camaro Join Date: Jul 2017 Location: missouri Posts: 705	don't want to be the bearer of bad news. they shouldn't whine no matter what speed or milage on them. its not the gears it was the install. poor install cost me 1500 bucks and a new set of gears I have AAM 3:70 gears on a Detroit tru trac. first install sounded just like yours. was going to take mine back to the same dude but why? so he could screw it up again. I apologize but I think you have problems. I hope you don't I went 1 gear oil change and 2000 miles and all it did was get worse. took it to a guy nwho knew what he was doing no whine straight out of the box 10k miles still no noise what so ever

02-10-2022, 08:04 PM	#6
oldman14ss Drives: 2014 1ss camaro Join Date: Jul 2017 Location: missouri Posts: 705	tolerance on my pinion was so tight that it didn't need shims.

02-11-2022, 07:24 PM	#7
2010BlackCamaroSS Drives: 2010 Camaro 2SS/RS - L99 Join Date: Jun 2021 Location: MS Posts: 128 View My Garage	Thanks for all the replies, fellas. I know I have read several times that they shouldn't make noise. If it makes a difference, I did upgrade the diff bushings and installed an LPW cover. I hear that can increase NVH. I knew the 1st shop I took the gears to did a horrible install job; it was clear from the gear pattern and the ratcheting sound the diff made when rotating the pinion. Luckily, they admitted they couldn't do the job properly and didn't charge me any money. However, they gouged up my case pretty bad, so I'm going to have to bill them for the damage. I decided I didn't want to take a chance on another shop that I didn't know anything about, so, for piece of mind, I took it to a shop that has a great reputation on this site. If they can't get it right, I don't know what else to do. I have been babying the gears (which is excruciating) so that they are broken in properly, but it sounds like I've been wasting my time.