BMW M5 Forum and M6 Forums banner

1 - 20 of 30 Posts

·
Registered
Joined
·
3,968 Posts
Discussion Starter #1
ok maybe some of you guys have had an issue like this before and can help me out. i've been trying to figure out this high speed vibration for the last couple months. the vibration is felt around 80-90mph speed range. it is most prominent through the floor/gas pedal area in the front, odd as usually front end high speed vibrations you feel more through the steering wheel. i can feel it very slightly through the wheel but its more felt through the floor. i've checked and re-checked the front suspension for play and can't feel anything by shaking the wheels. i've eliminated the following culprits,

wheels/tires, just installed a new set, no effect issue
replaced front hubs/bearings, no effect on issue
replaced front thrust arm bushings, no effect on issue.

im running 20mm spacers on the front. if i remove them the vibration is just about gone so whatever the issue is the spacers make it worse/more pronounced. the only thing left i can think of is the center link but i've never seen a bad joint in a center link cause a vibration and as i said the weird thing is that you feel it more in the floor than in the steering wheel. So any ideas, what haven't i thought of or am overlooking here?
 

·
Banned
Joined
·
3,793 Posts
What brand tires? I had this on my Lexus and it was bad tires!! I replaced bearings, and other parts, but in the end it was bad tires, they were brand new too!


Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
272 Posts
If I had to guess I would say it is the spacers themselvs. You mention when removed the vibrations is almost gone but if were honest no matter what there is going to be slight vibration in any car at those speeds.
 

·
Registered
Joined
·
750 Posts
We're not allowed to go that fast in CT.:3:
I think the spacer is simply giving the wheel assembly a longer "lever arm" advantage to transmit road vibrations. I have found with various toe settings this sort of thing and it isn't always transmitted through the steering wheel. How have you eliminated a tire as the culprit? Because it stops with the spacer out? It could be that there's a minor vibration with the spacer out but now magnified with it in. Additionally, perhaps the wheels need balancing. Admittedly most harmonics aren't present at the speeds you mention from what I remember, I mean read in the paper...:7:
 

·
Registered
Joined
·
877 Posts
I would vote wheel spacer. When I intially purchased my e38 car it had them in. I had some work done with my car that required removal of the wheels. When the tires and spacers were put back on I had a strange vibration that was really not through the steering at speeds of 70-80 mph. When they inspected the car they found a wheel spacer was broke. Removed those spacers and problem was gone.

This happened to a gentlemen who put aftermarket rims on his 85 535i to get away from metric size tires. A wheel spacer was causing a strange vibration that he could not diagnose.

Re-Inspect those wheels spacers and their application you might find your problem, since you have done almost everything else!

Good luck!

James
 

·
Registered
Joined
·
4,488 Posts
You could try doing run-out checks with a dial indicator on the various front wheel components, moving out from the bearings, so face and diametral runout on the bare hub flange, then the bare rotor, then the spacer and then tire and rim.
 

·
Registered
Joined
·
12,922 Posts
Have you tried to balance the wheels/tires/spacers on the car as an entire assembly? If you put the car in the air, and spin the wheels at 80 mph, do you still get a vibration?

At 20mm, these are hubcentric, can you sure the holes for the spacer bolts are as true as the wheel holes? Older spacers sometimes had a slight bit of overage in the size of the hole, so when you mounted the spacer, the spacer was not dead center on the hub assembly. That of course will show up as a vibration.

Are you sure there is nothing wrong with any of the spacers? Brand? Any members nearby with same sized spacers that can do a swap?

Regards,
Jerry
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #11
guys i appreciate the input and i don't mean to come off like a dick but if you're going to offer suggestions will you please actually read my posts. I've stated it twice already that its not the wheels/tires. I just installed new wheels/tires and made no impact on the issue. the spacers themselves are not the issue either as tms sent me another set to try, no difference. i replaced the center link today as its the only part of the front suspension that i think could possibly be the culprit. when i got the old one off i checked the joints and there was some play in the left side ball joint. couldn't feel it by shaking the wheel with the center link installed. so tomorrow on my highway trip to work i'll see if it made a difference.
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #12
replaced the center link, left side inner ball joint had some play in it but nothing major. made no difference on the vibration. took the spacers out as they just make it worse. maybe they are part of the issue, idk. the fit tight on the hub but if i lay them in the wheel bore they can be moved a couple mm's side to side. both sets were like this though.
 

·
Registered
Joined
·
69 Posts
It's really weird that a front end vibration would be more noticeable through the body than the steering wheel. When you say it's most obvious in the driver's footwell, have you compared the vibration to other seats in the car? This is clutching at straws, but it might be worth downloading a vibration meter app (totally inaccurate, but probably good enough to compare between locations in the car), lifting some carpet and trying to find the location nearest the source. Not something I'd be too keen to do at 90mph though!

My gut feel is its something out of balance that rotates at road speed. Maybe it's nothing to do with the front wheels, but spacers are amplifying the vibration, just to confuse you. hmmm
 

·
Registered
Joined
·
9 Posts
Just a shot in the dark, but if the vibration is through the floor and not the steering wheel are you sure that it's not coming from the rear? Floor-only vibration is usually rear-axle related.

There is also a good vibration diagnosis chart on Tirerack that could give you some brainstorming ideas of where to look as well. It's very basic but it's always good to start fresh from the top to make sure that you didn't miss anything obvious :)
 

·
Registered
Joined
·
10,186 Posts
I know you say it is not the tires but...If the spacers make it worse that is because you are effectively making, for a lack of better word the fulcrum longer, so you get more vibration. Two sets of tires can be out of balance unless you had them roadforce balanced. Even then, because out of round is out of round. If you have not then try that. There is even a better one than the static one, balances them on the car, never seen it just read about it.
i am sure there is something else off but you have been unable to locate it, nor do you seem to be able to exactly say when it started, could it have been during lowering? Often guys forget to loosen the thrust and wishbone arms when they lower and the bushing have extra tension.
 

·
Registered
Joined
·
529 Posts
If the vibration is more pronounced through the floor, and felt only slightly through the steering wheel, it could be a driveshaft issue. If it's putting enough vibration through the chassis you could feel it in the steering wheel slightly. It could be getting a little out of "frequency" at a certain speed, and an old CSB rubber boot might be letting it wobble a little more than desired. Idk man, keep us posted.
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #17
i checked the balance of the front wheels. road force balanced them, last set and the set i have currently. i was thinking the same thing, maybe im looking in the wrong place and its in the rear but you don't really feel it much in the seat. its mainly in the drivers floor/gas pedal and slightly through the steering wheel. i have powerflex tab's installed and afaik they don't have to be torqued with the suspension loaded. i can try slacking the control arms and thrust arms but i doubt its going to make a difference though at this point i'll try anything. i thought maybe driveshaft or rear axle but if it were in the rear im sure i'd be feeling it in the seat etc. removing the spacers lessens it so one would think it has to be the wheels/tires but it's not. the only thing i can think of related is the tires are flat spotting overnight and just not straightening back out during my commute which is about 30mi each way. idk, just doesn't make much sense.
 

·
Registered
Joined
·
10,186 Posts
It does not make any sense but ****e happens. Does the passenger seat vibrate near the top? Have you tried lower pressure in the front? They say that is a valid test for tire round. Appearently the higher pressure reduces the contact spot and makes tires that are not perfectly round,none are, feel more out of round. Spacers would add to that.
But as said it is likely something else with play that allows the vib to start. You have checked your toe? Excessive toe out or in can cause, I would not call it a vibe more like chatter and that would only happen at speed. Spacers would make that a lot worse maybe even to vibe from chatter.
 

·
Registered
Joined
·
3,968 Posts
Discussion Starter #19
yeah the pass seat does shake at the top. i'll try and re-torque the suspension arms and lower the tire pressures tomorrow, iirc the are not very high anyway. think i set them around 36 front and rear.
 

·
Registered
Joined
·
10,186 Posts
I have the same shake in the seat but I don't feel it. I only have it with my square setup. I always suspected it was toe chatter as result of the higher slip angle of the wider tire. I toed out aggesively for the narrow tire to rid the car of understeer. I did not change my toe when I went square. Insteed I went back to the 245 up front. Are you 275 up front? If you are plus the spacers I would guess you need a toe angle of zero.
 
1 - 20 of 30 Posts
Top