[ashmostro]

EDIT: Identified and partially solved the problem... see here

I'm wondering if it's the M3 bushings... I recently had quite a bit of suspension work done on my car and everything was whisper quiet.... until it rained. Since then and particularly when the car is colder I have a very obnoxious low-frequency creaking/squeaking coming from mostly the front end (but there may be a bit in the back too) when going over larger bumps or offset bumps. The behavior and nature of the squeak leads me to believe it's the M3 sway bushings being too tight and not lubricated properly (Redline CV grease was used, which may not have the waterproof qualities that a silicone based paste does).

Has anyone else had a similar experience, and if so, did simply regreasing the bushes solve the problem for you? I will probably do this with the proper silicone lube but wanted to check in for other ideas and perhaps other things to look at.

Crossed off the list:
- the coils and camber plates are solidly installed. there are no loose parts or undertorqued nuts
- all suspension arms are torqued down and do not demonstrate play
- steering and handling feel great, just noisy

FWIW i am running the 28mm e93 bar up front and the 22.5mm e92 bar in rear with all the respective OEM brackets and bushings. Rest of mods in sig.

Thanks in advance to those who respond

[e679]

Did you check the endlink?

[335dFan]

When I had all my suspension work done many months ago, including the M3 sways, I had a bunch of strange noises at first over bumps. But after a while they either gradually went away or I just got used to them. Anyway, I don't notice anything now.

[Meeni]

I do not have the M3 sway, but similar symptoms on my Audi were indeed lack of lubricant on the sway bar bushings.

[ashmostro]

Originally Posted by e679

Did you check the endlink?

I did and they are secure on both ends. In fact I whacked every suspension component with a mallet with the car on a kickstand and nothing rattled or sounded out of place.

I think I'm going to switch to powerflex bushings and silicone paste and see what happens...

Thanks folks

[e679]

Originally Posted by ashmostro

I did and they are secure on both ends. In fact I whacked every suspension component with a mallet with the car on a kickstand and nothing rattled or sounded out of place.

I think I'm going to switch to powerflex bushings and silicone paste and see what happens...

Thanks folks

What I meant was if you have lower your car. The endlink may either be too short too long.

[zeenon53]

Originally Posted by e679

What I meant was if you have lower your car. The endlink may either be too short too long.

When you lower a car your supposed to change the endlinks? Is there a way to measure how long the endlinks should be?

[robc1976]

Originally Posted by ashmostro

I did and they are secure on both ends. In fact I whacked every suspension component with a mallet with the car on a kickstand and nothing rattled or sounded out of place.

I think I'm going to switch to powerflex bushings and silicone paste and see what happens...

Thanks folks

I have creaking and have Powerflex subframe bushings, but also have solid differential bushings. I will say didn't grease my M3 sway bar but my creaking is from rear mostly.

[robc1976]

Originally Posted by zeenon53

When you lower a car your supposed to change the endlinks? Is there a way to measure how long the endlinks should be?

when car is lowered you need to lengthen them put car on rhino ramps and adjust end-link so it slides into sway bar end easily. Basically with car at ride height sway bar shouldn't be loaded.

[ashmostro]

So I learned something very interesting today that makes a crap ton of sense (technical term).

The typical Germanic we-must-be-different engineered M3 sway bar bushings don't function at all like traditional bushings. They are NOT designed to be fixed relative to the sway bar like traditional rubber or polyurethane bushings, including aftermarket bar bushings. They are designed to be an interference fit and compress against the bar, and rotate WITH the bar, just like some of the suspension arm bushings do on most cars including BMWs. That's why the M3 bushings have the second metal sleeve inside a sleeve thing going on.

This means a few things: you need to torque down the bushing brackets with the bar in neutral fully loaded position, just like the suspension arms. And second, you DO NOT LUBE THE BUSHINGS AT ALL. Especially not with any type of CV lube that actually might eat at the rubber in the bushings. In my case, rule #2 was broken and that's why I'm getting noise. As such, and because I don't like the extra spring constant of a rotating bushing, I just ordered some powerflex urethane bushings and will use liberal amounts of silicone grease and enjoy not having to worry about torqueing down the bars in fully loaded position.

They should arrive next week, and then hopefully the noise saga will be over. Though I will need to periodically regrease the bushings, if I use the right kind of lube and a lot of it, that shouldn't need to be very often. I could also wrap the bar in teflon tape to aid in lubricity and extend lube intervals quite a bit.

[robc1976]

Originally Posted by ashmostro

So I learned something very interesting today that makes a crap ton of sense (technical term).

The typical Germanic we-must-be-different engineered M3 sway bar bushings don't function at all like traditional bushings. They are NOT designed to be fixed relative to the sway bar like traditional rubber or polyurethane bushings, including aftermarket bar bushings. They are designed to be an interference fit and compress against the bar, and rotate WITH the bar, just like some of the suspension arm bushings do on most cars including BMWs. That's why the M3 bushings have the second metal sleeve inside a sleeve thing going on.

This means a few things: you need to torque down the bushing brackets with the bar in neutral fully loaded position, just like the suspension arms. And second, you DO NOT LUBE THE BUSHINGS AT ALL. Especially not with any type of CV lube that actually might eat at the rubber in the bushings. In my case, rule #2 was broken and that's why I'm getting noise. As such, and because I don't like the extra spring constant of a rotating bushing, I just ordered some powerflex urethane bushings and will use liberal amounts of silicone grease and enjoy not having to worry about torqueing down the bars in fully loaded position.

They should arrive next week, and then hopefully the noise saga will be over. Though I will need to periodically regrease the bushings, if I use the right kind of lube and a lot of it, that shouldn't need to be very often. I could also wrap the bar in teflon tape to aid in lubricity and extend lube intervals quite a bit.

very good info my friend...I found a post right before you posted that said no grease!

I want to know more about the tightening when loaded, only time the bars is loaded is when taking a turn...so wonder how they preload the sway bar.

I am guessing they adjust the correct end-link length, bolt end-links to sway bar and then Jack front of car up on center hacking point letting tires hang loading the bar? Then tighten them down?

The control arms are under load when at ride height, the sway bar should not.

[ashmostro]

can also just tighten the brackets down holding the bars in "loaded" position, and then connect the end links...

all ridiculous Germanic arrogance if you ask me... nothing wrong with urethane IMO.

[robc1976]

Originally Posted by ashmostro

can also just tighten the brackets down holding the bars in "loaded" position, and then connect the end links...

all ridiculous Germanic arrogance if you ask me... nothing wrong with urethane IMO.

Agreed

[ashmostro]

I'm not sure what your background is bro, but being an engineer by training (but not current trade) when I take apart my car and see what unnecessary complexity is baked into my e92's design it aggravates me. So many people look down on Japanese vehicles as being technologically inferior but a cheaper, simpler, more reliable solution that performs the same is what I like to call "better"

[mlifxs]

in case you haven't resolved, another thing to check is the centering of the bars. Recently installed a front sway, after a couple weeks started making noises. From inspecting the end link clearance with a wrench, found that bar was off center by about 3/4in, so shifted backed to center, noise went away.

[Efthreeoh]

Originally Posted by ashmostro

I'm not sure what your background is bro, but being an engineer by training (but not current trade) when I take apart my car and see what unnecessary complexity is baked into my e92's design it aggravates me. So many people look down on Japanese vehicles as being technologically inferior but a cheaper, simpler, more reliable solution that performs the same is what I like to call "better"

This is off the topic of suspension, but on the topic of complexity...

So if you ever noticed the operation of the lighted vanity mirror in the sun visor in the E90 (or F30), the switching for the light is overly complex. The visor light comes on when the door is slid open and the visor is pointed straight down, but when the visor is pushed to angle against the windshield (i.e. to block the sun) and the mirror door is open, the light then goes off. Also, when the mirror door is open and the light is on, if you swing the visor to the side window position, the light then goes off. If the mirror door is open and the light is on, when to put the visor back to its "rest" position (flipped up against the headliner) the light goes off. The switching is way too complex and costly.

Go look at say the Cadillac ATS (or most GM products). The vanity mirror is covered by a door. Open the door, the light comes on, close the door the light goes off. Swing the visor to the side, if the door is open, you'll need to close it because it will hit your head (and the light goes off). Put the visor against the windshield to block the sun, you need to close the door because it blocks your vision to the road (the light goes off). Put the visor back to the rest position and the door automatically closes (and the light goes off). Much simpler and cost effective design.

[ashmostro]

Elegance need not be arrogance. "Hey, look what we can do! We are smarter than all of you! "

we are probably going to get in trouble for talking like this... let's talk later at the secret meeting...

[zeenon53]

Originally Posted by robc1976

when car is lowered you need to lengthen them put car on rhino ramps and adjust end-link so it slides into sway bar end easily. Basically with car at ride height sway bar shouldn't be loaded.

Thanks. So i'm on kw coilovers and still have a pinky's gap between the tire and fender. Do you think I need longer endlinks?

[cvc 22349a]

Originally Posted by zeenon53

Thanks. So i'm on kw coilovers and still have a pinky's gap between the tire and fender. Do you think I need longer endlinks?

Do you get a clunking sound going over speed bumps or turning up a steep driveway?
You can look under your car to see if the front sway bar is on a horizontal plane.

[cvc 22349a]

M3 sway bar bushings/bearings here. No grease; no squeak.

[ashmostro]

Originally Posted by cvc 22349a

M3 sway bar bushings/bearings here. No grease; no squeak.

indeed - as explained above. Grease IS the problem with these.

[zeenon53]

Originally Posted by cvc 22349a

Do you get a clunking sound going over speed bumps or turning up a steep driveway?
You can look under your car to see if the front sway bar is on a horizontal plane.

I do actually, not regularly but it does happen. I was under the car the other day and somehow the drivers side swaybar endlink came loose.