Noises with aluminum subframe and diff bushings

[jiggysnitz]

My 6sp e92 has fairly loud clunks from (I think) the diff when switching gears, going on/off throttle, loading unloading the drivetrain. I have checked all the diff bolts and everything seems fine. I have aluminum diff and subframe mounts so perhaps this is normal with things hard mounted? I have not checked the driveshaft carrier bearing as I don’t want to pull all the other parts off to get a look at it if I don’t have to.

Those of you with aluminum diff and subframe bushings, how clunky is your shiz?

[pbonsalb]

With aluminum subframe and diff bushings, there is nothing to absorb noise or vibration. Expect them to be transmitted and to hear them. You are not telling us that you changed the bushings and heard nothing and then a year later you noticed noise and vibration.

[amrazM]

I have solid subframe bushings and diff bushings, clunking is not normal. Don’t be lazy, inspect your driveshaft before it leaves you stranded

[jiggysnitz]

I will pull it apart and look this weekend. Just wanted to double check beforehand. I have only had the car 2 weeks!

[Redd]

Zero NVH with solid subframes for few years now.

[pbonsalb]

Originally Posted by Redd

Zero NVH with solid subframes for few years now.

Is that zero NVH with solid subframe AND solid diff bushings? No one has issues with just solid subframe bushings.

[Redd]

Just subframe. Helping him eliminate one item since the OP isn't sure which it is.

[Malek@MRF]

Solid sub-frame mounts do not add any noise, harshness or discomfort to the car. If you hear anything or the car is behaving oddly, something is either loose, or problematic elsewhere. Differential bushings will not add clunking either, they will merely add gear noise, no harshness, no vibration.

[pbonsalb]

Stiffer diff bushings can whine and sing. Even my 95A poly ones whine.

[jiggysnitz]

Originally Posted by Malek@MRF

Solid sub-frame mounts do not add any noise, harshness or discomfort to the car. If you hear anything or the car is behaving oddly, something is either loose, or problematic elsewhere. Differential bushings will not add clunking either, they will merely add gear noise, no harshness, no vibration.

I appreciate the responses everyone! I have ordered a new driveshaft/guibo/center bearing as that is the only thing I haven't checked yet. Also the car is just under 100k so it is probably about time for those anyway, judging by what I have read from others with similar milage.

MRF actually did the solid subframe and diff bushings in my car (at least that is what the receipt and the stamp in the bushing says 👍🏼

[pbonsalb]

The noise can also be a dry diff input shaft. There is a TIS on how to grease it. Or it could be a worn u-joint in the DS center. Whatever noise will be more audible due to the solid mounting of the diff.