Need Help/Advise - Rear Lower Damper Rubber Shot + Rubber/Camber Upgrade.

[JuniorM3]

Hi Guy's need some /advise.

My hard driving caught up to me. My RR lower damper rubber is shot. (IS IT A RUBBER???) Anoying rattle and the damper (lower part) keeps shifting forward and rubbing against the lower A-arm. (8)

I had her up on the lift and used a big screwdriver to prie the damer of the A-Arm and center it in it's space.
I think the rubber of #2 is busted. (It sits between 8 and 9 of the first picture)


I'll have actual pictures up here on monday.

But the rattle is back, harder the ever.

So on monday I need to get serious and check it out and order some replacement parts.
The question is....OEM or suspension overhaul with aftermarket stiff rubbers for the Front+Rear and subframe subframe?
And where can I order them? Anybody have experience? Pricing?

I don't want a rubber set that's to extreme for daily driving with rattles and noise in the cockpit.

Does andybody have a good afordable Front+rear Camber set while we're @ it.
This car could realy use some camber!!!

I think there is another 2 seconds a lap (depending on which track) in just stiff rubbers and some camber F+R.

Thanks, Jr.

[Radiation Joe]

Knowing where to replace the compliant rubber parts in the e46 was very helpful. In the e9x, I believe most of the bushings are already solid.

I think you are actually interested in the area at "5" in the upper diagram. That's where the shock mounts.

Dinan sells front track arm spherical bearings to replace the crappy fluid filled stock bushings (they actually ride better than stock). A couple of venders sell toe links with SBs as well (component 13 in the upper diagram).

They're not cheap, but you might find rear suspension control arms with better bushings in the BMW Motorsport catalog. You can bet the GT4 cars will have any weak bushings replaced. Those parts should be in the catalog. I believe the GT2 cars (like the Rahal/Letterman cars) everbody thinks are soooo cool don't have any parts interchangeable with our cars.


Turner Motorsports sells a lot of Group N (GT4) parts. They have subframe mounts and stiffer bushings for quite a bit of the e9x suspension.

Look to the bottom of this page for the stuff Turner sells.

[JAJ]

BMW has already replaced many of the rubber bushes with metal-to-metal spherical joints. There's not a lot left to upgrade. Having had the E92 M rear suspension apart a few times, I'm not sure that your clunk is likely to be in the damper mounting where you think it is. They're rubber, but they're really tough rubber. If it moves a bit when you pry on it, it's supposed to. On the other hand, there are a number of spherical ball joints in the rear suspension, and it's more likely to be one of those getting noisy. Or it could be the subframe.

For instance, I recently had a hard-to-pin-down knocking in my stock suspension and the dealer determined that the rear subframe mounts had worked loose. I had some track day miles on the car, but I run on slower tracks and haven't gone anywhere near as fast as you, and still the subframe had developed the urge to file for separation from the rest of the chassis.

If you want to make the handling tighter and find your noise at the same time, then do some shopping from Dinan and from Turner, as Radiation Joe suggests.

The rear subframe and differential mounts (from Turner) will keep the subframe from moving around. The front and rear ball jointed parts from Dinan will stop that twitch or sidestep you feel every time you get on the brakes hard at high speed. By the time you've done this work, you'll have taken enough of the rear suspension apart to know exactly where the noise is coming from.

[rzm3]

How many miles do you have on the stock suspension? I would check all the bolts before ruling anything out.

There is no bushing replacement for the stock lower rear shock mount (unless you go aftermarket shocks). Also it is connected at bolt 5, not 7/8/9.

For a racing car driver like you, might as well get aftermarket coil over. Since you are in Europe, KW CS or Competition 2-Way should suit your needs pretty well. I have a set coming next week and will share more info on them.

As for upgrade options:

Front: the front sub-frame is bolted solidly in place, so there is no need for replacement. There are various camber plates available, but most don't work with stock springs/struts.

Rear: the M3 GT4 sub-frame has solid mounts to the chassis, but the bushings for various arms are still rubber. Turner offers solid bushings for the sub-frame and differential, but not for the arms. The rear camber is adjustable from factory and it should offer you more than enough adjustment range.

[Bubbles]

Originally Posted by Radiation Joe

Knowing where to replace the compliant rubber parts in the e46 was very helpful. In the e9x, I believe most of the bushings are already solid.

I think you are actually interested in the area at "5" in the upper diagram. That's where the shock mounts.

Dinan sells front track arm spherical bearings to replace the crappy fluid filled stock bushings (they actually ride better than stock). A couple of venders sell toe links with SBs as well (component 13 in the upper diagram).

They're not cheap, but you might find rear suspension control arms with better bushings in the BMW Motorsport catalog. You can bet the GT4 cars will have any weak bushings replaced. Those parts should be in the catalog. I believe the GT2 cars (like the Rahal/Letterman cars) everbody thinks are soooo cool don't have any parts interchangeable with our cars.


Turner Motorsports sells a lot of Group N (GT4) parts. They have subframe mounts and stiffer bushings for quite a bit of the e9x suspension.

Look to the bottom of this page for the stuff Turner sells.

Junior keep us posted, I'm curious how the stock suspension holds up over time. Especially in the case where the car is track on a "not so smooth surface" like Sebring. Best of luck with the repair.

[JuniorM3]

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