Coilover Installation Issue?
 

I'm posting this here as the F57 area doesn't seem to get much traffic.

A competent tech and I recently installed ST X coilovers and NM GT rear sway bar on my 2017 MC S F57 convertible with about 24k miles on the clock. During the install, the spring perches were set at the the mid point of their adjustment range both front and rear. That resulted in the car sitting about 1.5" lower than stock. Looked cool but during the initial test drive there was a noticeable "shimmy" in the steering wheel as the car accelerated thru 17-20 mph, perhaps slightly more noticeable during a turn e.g. turning rt at a stop sign. We then adjusted front/rear spring perches to the top of their adjustment range and the shimmy went away. At that point the car sat about 3/4" lower than stock. Car was then aligned. The car drove and handled great thru all speed ranges I drive at.

Still in search of a perfect "look" I adjusted the perches down to lower the car somewhat, splitting the difference between 3/4" and 1.5" lower than stock. Shimmy came back, but much less noticeable. Had the car aligned (at a competent local german car repair shop) again. Tech said all was well and he didn't need to change anything. I asked him about the shimmy and he said it was "the nature of the beast" with aftermarket coilovers. Not certain I bought that though.

Anyway, I continued to worry about the shimmy and after a week or so raised the car back up to 3/4" lower than stock position were the shimmy once again disappeared. I have checked and double checked to make certain springs are properly seated, everything is tightened properly, etc. If it makes any difference the NM rear sway bar is set at the "softest" position.

It seems clear to me that the shimmy or lack thereof is directly related to the ride height of the car. I don't know if this issue is specific to my car or F57 convertibles in general but its driving me crazing. And in case you're wondering, I haven't discussed this w/ my dealer yet.

Any thoughts would be greatly appreciated.

Thanks. contented

I have no experience in the matter, but I believe folks in older model MINIs have reported similar issues when the car is lowered too much. If I remember correctly, the shimmy to which you refer to is caused by stress being put on the cv axles due to suspension being too far out of spec. Prolonged driving in such conditions leads to CV axles failing.

Like I said, I'm no expert. Just seem to remember reading this quite a few times here and on MINI FB pages.

My F56 has been lowered 1.5 inches for more than 2 years, first on NM springs and now on BC Racing coil overs. I have never experienced a “shimmy” as a result. I’m changing to RMW coil overs soon and plan to set the same ride height. Don’t anticipate any problem. (Knock wood)

I'm beginning to believe it has something to do w/ North American F57 cars. Believe it or not, Mini does not sell a John Cooper Works Pro Suspension kit for the F57 convertible, which was my first choice. My dealer's service manager verified that directly w/ Mini North America. They didn't tell him why. Must be a reason.

Now, there are a number of the well known vendors who sell a JCW Pro kit they say will fit the F57 and it probably does "fit" but will likely have the shimmy issue I experienced. My ST X coilovers came from Tire Rack. Interestingly enough I discovered very recently that KW's website has a picture of a low sitting F57 (it appears to have a European license plate). Yet when you go to the KW USA site, they do not list any coilovers for a US F57. Do the same thing on the European website and there are many to variants to choose from. Go figure.

Haven't talked to anyone who knows unequivocally. But my shimmy is gone, car handles great - I just wish I could get it to sit a little lower w/o any ill effects. In hindsight I wish I'd have bought F56 JCW instead of the convertible. Could have for about the same money. Oh well.

Still love my little car for sure.

Shimmy is caused by the axle.
Higher miles like 24k miles sets a wear pattern in the inner CV joint bucket.
Lowering the car moves the joint deeper into the housing off the wear point due to camber going negative and pushing the inner the joint slightly deeper into its housing.

As you accelerate, the front end is raising slightly the camber is pulling the joint in and out of the original wear spot in the housing (tramlining).

If one could get the camber back to pre lowering spec, vibration _may_ go away.



Vetevette wouldn't have that problem, as he's been lowered since the beginning.

This is not limited to MINI.
There is a fix I believe for S2k owners that entail a spacer at the
trans output shaft to push the bucket in away from the wear spot.

anecdotal experience on a new car to confuse the issue.

2019 JCW HT. put V2 coilovers on with less than 200 miles on the ODO. starting setup was front and rear camber to -2, front ride height down 1/2" from V2 starting point and rear 5/8" down. rear control arms, full Powerflex bushing replacement and Quaife done at the same time. driver's side axle pulled completely apart ON THE TEST DRIVE. now maybe it was a manufacturing defect, and Mini did cover the part under warranty (that took more than 2 months to get from Germany, which is beyond ridiculous). when re-assembled, the rear was left at -2 but we brought the front back to -1 (which will result in better handling anyway). have driven it like i stole it from that point on with no ill effects....yet. Way reports he's taken street cars to -3 front camber with no ill effects, but i've decided not to risk going further until more is known about these cars. it makes me wonder if providing all the adjustment from the bottom bushing (the V2's do not have camber plates) might be outside the design parameters of the axle. in any case, i'm not looking forward to another 9 week wait for an axle.

Was there any resolution to this other than raising the car up close to stock height? I'm over from the BMW X1 F48 forums and recently installed a set of KW V1 coilovers on our 2018 f48 and have the exact same issue. There are actually a couple of us who have the same issue. Have noticed the rear drive of our Xdrive has a weight ballast with the frequency 38Hz on a label and was wondering if the angles of the cv have thrown off this counterbalance fix BMW have implemented.