4.10 Ring and Pinion Gear Whine Noise

[sapote]

Thanks all for the info, I appreciate it. We did use a pinon depth tool to determine the pinon shim since the etched number was different on my 4.10 pinon but we kind of resorted to checking the pattern with different shims to get it as centered as possible. I will still reach out to Racewerkz and Bavarian Workshop to see if I can have one of them go through everything on my 4.10 diff to make sure everything looks alright. I'll probably also go back to stock diff bushings to bring the noise levels back down. I'll post up any updates.

The pinion has to be set with the depth tool, then using shims on the ring gear to achieve the desired patterns. If you don't set the pinion then you're swimming in 2 dimensional variables and almost impossible to get it right.

[mrgizmo04]

Will add for purposes of public data, since we spoke via PM. My wife calls my car Chewbacca, it whines like crazy. Started on poly subframe bushings and poly diff bushings. Went to stock diff bushings (stayed with poly subframe), still whines.

Sent from my SM-G950U using Tapatalk

[jvit27]

3.91 and 4.10 are Motorsport gearsets - most will have some whine. Some are lucky and they don't. My 3.91 does on initial tip-in and overrun.

[Rudbari]

Had 4.10 and it’s only whines during deacceleration with oem bushing

[fattycharged]

4.10 here, there is a noticeable whine, but that is to be expected. I would say it's all relative to how sensitive you are to high pitched noises, older you are the less you will likely notice. As everyone else has stated, bushing choice will play a major part in noise transmitting to cabin.

I'm always curious as to whether those who are very bothered by it have a completely stock interior down to the styrofoam that holds the pump in the trunk.

[Arith2]

Skip to 12:50 and he shows a perfect pattern on how the gears are supposed to touch.

[maupineda]

Hi all,

I am trying to gauge other people’s experience with 4.10 gear sets and whether or not they are getting noticeable gear whine. I’ve read up a lot and see many people saying their 4.10 gears don’t whine at all while others say they do whine and it’s normal. I recently assembled a 4.10 differential and the gear whine is worrying me that something was setup improperly.

Just for back ground, I put together my diff with a friend who is a BMW tech and pretty familiar with differential assembly. Originally I put in all new pinion and carrier bearings, new seals, new Wavetrac LSD unit and BMW 4.10 gear set. We sourced pinion and carrier shims to properly set pinion depth, carrier shims for back lash, set pinion preload and carrier preload to spec. Pattern looked ok, centered on coast and drive side etc. I already had all 3 AKG poly diff bushings , subframe bushings, motor mounts , trans mounts etc. I Put the 4.10 diff in the car, it whined from the start, drove a few hundred miles, same thing. The poly diff bushings always caused a faint whine with my stock 3.62 diff but nothing like the 4.10’s do. I took the diff back out, checked everything , looked fine, sent the gears for REM finishing to hopefully quiet things down. Put the diff back together with REM treated gears checking everything again, all is within spec again. Differential still whines , slightly quieter , but barely. I’m going to drop it out again and possibly take it to someone for a 2nd opinion, make sure everything is assembled properly and if so just switch to stock diff bushings to quiet the whine (I hate the whine).


What has everyone else experienced with noises and their 4.10 gears?

Anybody know any reputable differential shop in SoCal that could looking things over for me on my diff?

Thanks all!

Another 4.1 user here.

In my build thread I documented my gear patterns. I tested two setups, and the one with the original shim is best, but still there is a slight whine. my gears were not REM as I had read it does not really help much.

OP, or anyone in the know, where can I find the depth tool? I have searched up and down with no luck. I am motivated to get the diff down once more if I can find the tool just to double check.