2022 M3P Front Suspension Creak/Noise Fix!

[Flewis7]

I have a '22 M3P with around 12k miles and the front suspension started creaking. Noticeable at slow speeds (pretty loud) and it sounded like an ancient wooden ship.

First thing I did was get on the ground and have someone move the steering wheel back and forth while the steering wheel was close to lock in both directions (so I could see the suspension components fairly easily). I couldn't identify a specific item the noise was coming from, but it seemed to be lower than the upper control arms. It actually seemed to be coming from multiple places and was definitely originating on both sides of the car.

From research, the first suspect was the UCAs, so I checked them first. I disconnected the upper ball joints (super easy to do with a 15mm wrench and T-45 bit) and checked them. They moved smoothly with fairly low resistance and had no rough spots or noise. I went ahead and moved them through their full range of motion multiple times to make sure the grease was well distributed. I also moved the upper control arm up and down through its range of motion, but couldn't reproduce any noise (though there was no load on it). Then I put things back together. Didn't make any difference.

Then I grabbed a can of Dupont Teflon dry film lubricant. I decided to spray down all the rubber bushings, hoping they were making the noise. There are quite a few in the suspension. I also hit the front sway bar mount bushings. They're bonded to the bar, but they're made in two pieces, so I think there is some chance of noise coming from them if they rub against each other. There isn't any point in spraying any of the ball joints. They have rubber boots and are sealed. The upper ball joint at the end of the upper control arm is a ball joint and there are several others in the front suspension. Spraying them isn't going to do anything.

Finally, kind of on a whim, I sprayed down the upper and lower spring perches on both sides. After thinking about it, I think this was the real fix.

She's whisper quiet again!

We'll see how long this lasts, but if it comes back I will just spray the spring perches and see if that fixes it again (for a while). If so, I'll look into something more durable.

 

[Gauss Guzzler]

Yeah, one of the drawbacks to the double-wishbone setup is that the spring perch isn't free to rotate, so the spring is unable to naturally wind/unwind as it compresses/decompresses. Turning the steering wheel doesn't twist the spring, but it does bend/bow which can allow the top coil to slip to a new angle on the flat rubber upper perch. Usually this is only a problem shortly after installation until the springs find a happy-medium position where they're not ever stressed enough to overcome the perch friction again. This is a big problem with aftermarket springs since people don't clock them ideally during installation so they take a while to settle, but the common advice is to *not* lubricate them as it may prevent them from ever settling.

None of the rubber suspension bushings have sliding interfaces that would be affected by lubricants other than the sway bar mounts, so this may be a more likely cause of noise that began after 12K miles and more likely to be fixed by lubricant.