BMW M5 Forum and M6 Forums banner

1 - 20 of 36 Posts

·
Registered
Joined
·
3,968 Posts
Discussion Starter #1
over the last couple weeks i noticed an annoying shimmy around 60-70mph, just while driving, not under braking. i checked the front wheels, no bends, re-balanced the tires, no change, checked the front suspension, nothing loose etc. so the only thing left was the spacers(20mm h&r hubcentric), removed them, shimmy gone. so wtf, has anyone had these go bad on them? they're not even a year old iirc.
 

·
Registered
Joined
·
176 Posts
Couldn't tell you why after visual inspection, but I too have had hubcentric spacers cause shimmy and vibration after a few thousand miles.
 

·
Registered
Joined
·
393 Posts
Change your thrust arm bushings. Having the wheels out mor (20mm spacer) puts twice as much stress on them. I had the EXACT same issue. ( and if your are lowerd) ..changed mine to power flex and no issues sence
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #4
bushings are relatively new, x5 ones. i had no shudder under braking. idk how these can go bad, i guess maybe stress on the lip of the spacer by hitting potholes etc put the lip out of round.
 

·
Registered
Joined
·
393 Posts
Naw they won't go bad. Hub bearing? Also if your thrust arm bushings were not installed correctly and preloaded then they could be shot
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #6
well something happened to one or both of them. bushings were installed properly and tq'd under load, nothing wrong with the hubs/bearings.
 

·
Registered
Joined
·
6,918 Posts
With spacers I've found you need to torque the lug bolts a few ft-lbs extra to be more secure. Do you have extended bolts to match the spacers?
 

·
Registered
Joined
·
47 Posts
I have a vote for the wheel spacers as a potential issue. Consider for a minute, the design of the hub. Engineering that piece, it is imperative to appropriately set your mounting surface as close to the hub bearing as possible. The further out you go, weight imbalance can be a big issue. Using spacers, you have now pushed out the rim which, let's be honest, isn't ever going to be perfectly balanced. What is causing any vibration is a slight weight imbalance. Even 0.5 ounces moved 20mm more out can have a dramatic effect at 70 mph. Torque is force x perpendicular distance. It's like a roll of quarters in a pocket during the spin cycle. Bet you'd notice it if it were spinning at 70 mph or, in the case of your wheel, about 21 times every second. Could be bearings, or could be the car wasn't designed that way. A natural frequency vibration that comes and goes as the add on does suggests the latter, to me anyway.
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #11
the spacer is the issue and they were good for all most a year, what im curious about is what actually happened to them or one of them that caused the shimmy. and yes i was using the correct longer bolts.
 

·
Registered
Joined
·
7,542 Posts
the spacer is the issue and they were good for all most a year, what im curious about is what actually happened to them or one of them that caused the shimmy. and yes i was using the correct longer bolts.
I also don't think anything changed with the spacer. Of course it's always important to have the hub surface completely clean and smooth/free of dirt/corrosion/etc, the spacer should also be completely clean. I'd roadforce balance the wheel/tire and also run the analysis on the Hunter machine to check the wheel runout. If the roadforce numbers are low (single digits), assembly is balanced, one (or both) wheel doesn't have runout in any dimension, then it's time to look at thrust bushings, wheel bearings, etc, etc...
 

·
Registered
Joined
·
47 Posts
CSBM5 hit it on the head. Right down to the Hunter.
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #15
guys i've done all of this, this isn't my first rodeo when it comes to vibration. im a bmw tech, i balanced the tires myself on our hunter road force balancer.

wheels balanced
all front suspension checked, tight
bushings good, torqued correctly loaded
wheels torqued correctly

fact of the matter is the shimmy was quite pronounced, after exhausting every other troubleshooting option i could thing of that was plausible(as i didn't want it to be the spacers) i took them off. now the car drives smooth as silk, shimmy completely gone. idk why its so hard to accept they are the issue. i accept it, just would like to know what exactly happened with them. only thing i can think of is that the raised centering ring on the hub is steel, on the spacers its aluminum as thats what they're made of. possibly from hitting potholes etc it deformed the ring out of round or something, idk. all i know is removing the spacers completely eliminated the shimmy.
 

·
Registered
Joined
·
960 Posts
I also put a set of spacers on in the front about 4000 miles ago (been 5-6 months) and I feel like my car is doing the same thing now at around 50+ mph.

I will pull off the spacers this weekend and see if that fixes it.
 

·
Registered
Joined
·
7,542 Posts
guys i've done all of this, this isn't my first rodeo when it comes to vibration. im a bmw tech, i balanced the tires myself on our hunter road force balancer.

wheels balanced
all front suspension checked, tight
bushings good, torqued correctly loaded
wheels torqued correctly

fact of the matter is the shimmy was quite pronounced, after exhausting every other troubleshooting option i could thing of that was plausible(as i didn't want it to be the spacers) i took them off. now the car drives smooth as silk, shimmy completely gone. idk why its so hard to accept they are the issue. i accept it, just would like to know what exactly happened with them. only thing i can think of is that the raised centering ring on the hub is steel, on the spacers its aluminum as thats what they're made of. possibly from hitting potholes etc it deformed the ring out of round or something, idk. all i know is removing the spacers completely eliminated the shimmy.
Super easy to test the theory...obtain some new spacers and test the car. :)
 

·
Registered
Joined
·
229 Posts
Interesting, as I too have noted a shimmy between 50 and 55 mph. It started about the time I got some new tires and so I have been blaming the tires. But despite repeated attempts at the tire shop(s) to smooth things out, it's still there. Perhaps my 10mil spacers were damaged as part of the install. As mentioned, a pretty easy hypothesis to test.
 

·
Registered
Joined
·
370 Posts
I had the same issue with ECS spacers and DFORCE wheels. The gap between the spacer hub and the wheel was just enough to give a vibration. I bought Ebay spacers from a seller called Dubstop and the problem was solved. Just another example of you don't always get the better from paying more.
 

·
Registered
Joined
·
6,014 Posts
I had the same issue with ECS spacers and DFORCE wheels. The gap between the spacer hub and the wheel was just enough to give a vibration. I bought Ebay spacers from a seller called Dubstop and the problem was solved. Just another example of you don't always get the better from paying more.
:eek:






PLEASE NOTE THAT I DO NOT OWN AN M5 AND THIS POST IS NOT INTENDED TO BE ARROGANT. PLEASE READ THE IMPORTANT REVISED DISCLAIMER THAT APPLIES TO THIS POST
 
1 - 20 of 36 Posts
Top