Lower Control Arm +

[Sundayjumper]

When I got my car it had a really bad shake from 60mph up. Bad enough that I had to always keep it under 60mph. Balanced the front tyres and it got a lot better, but still there.

All the joints seemed OK but I fitted Powerflex bushes anyway. A little bit better.

Changed the tyres and now it's 99% right. Still a very slight wobble but small enough that you wouldn't notice unless you were expecting it.

So my take is that it's a combination of everything. Some combinations work, some don't and there might not be an obvious logic to it.

[Rick27]

Thank you for the feedback guys. The tires that were originally on were Dunlop SP Sport Maxx and the new are Continental DWS. Size didn't change, 275/40 R20 in front and 315/35 R20 rear.

For some reason I never thought the actual tires could be defective, but I suppose that's a distinct possibilty. I wonder if the guy will actually replace the tires or whether I'd have to threaten a lawsuit if he doesn't. I really don't want to go through that crap, but fact is...and what I keep coming back to in my mind...everything was fine before the new tires. So frustrating.

[recklessspyder]

If you have the time and $$$ I would almost do the suspension anyway. I bought parts from ECS and then had an indy install them. I have the same amount of miles as you, but I also had a clunk and couldn't get an alignment. I think I paid about $500 total for parts and labor. My indy didn't even charge me for the initial inspection and told me what parts to buy.

If you think the tires are defective, go back to the place that installed them and tell them so. It becomes a problem with the manufacturer of the tire at that point.....unless the tire shop says you have a bad suspension

[Rick27]

Wow, only $500 for parts AND labor? I priced out the parts from one of the BMW OEM sites and they came to $450 or in that neighborhood.

I went to the tire guy today and told him the story. I'm going to bring him the car on Monday and he's going to "try" to determine which one may be defective. The service guy at BMW did mention to me that one of the tires (I believe it was rear/left) had an usual amount of weights on it. If I were a betting man, I'd say that's the defective one.

[recklessspyder]

Put your spare on that side and see if it stops....you could check that with all 4

[mobilejo]

Check the mounting of the wheel to the hub. 40-45mph shakes have happened to me on 3 cars and all were to do with not having a perfect wheel-hub mount.

I had it a few days ago on my X5 after getting my ARB links changed. Never had it before - it made no sense that it could be ARB links causing it so I took off the front wheels. I noticed the drivers side wheel was difficult to remove from the hub after the bolts where out, also the bolts seemed to be tight at a certain point on each rotation when I was undoing them suggesting they were in at a slight angle or the wheel was at a slight angle exerting weight on one point of the bolts.

Anyway, a visual inspection of the hub (after wire brushing all the old grease off) showed that the wheel centering flange of my hub (the bit that goes inside the wheel and the wheel centers on) had a slight lip at one point on its circumference.

I noticed the inside of my wheel had a matching 'cut out' where the 'lip' would sit comfortably. Once put the wheel back so that the lip sat in the cut out, it sat on the hub nicely and the wheel bolts went back in smoothly. 40-45mph vibration gone.

I have no idea how my hub & wheel developed these matching defects, but as long the wheel is mounted in the same way each time it drives fine. Obviously if I ever get new wheels I will need to get a new hub or get it machined.

Anyway, my point is check your mating faces, see if there is any thing putting the wheel at any sort of angle on the hub instead of flat. I read a forum post on an e39 forum of a guy who had this problem until he just kept changing which bolt hole in the wheel was mounted over a particular bolt hole in the hub.

[Rick27]

@recklesss - a great idea that I'm embarrassed to admit I never thought of.

@mobilejo - wow!! that's great information, thanks so much!! I'm going to actually print your post out and hand it to the guy who I bought the tires from, and have him check it while I'm there. Thank you!

[Rick27]

Well....the third balancing and remounting from the original place I bought the tires from and still the same problem.

So frustrating. I guess my next step is to have them check for defective tire and replace each one until it's solved.

I don't mind spending the money for the suspension parts if I knew that was the problem, but I don't. Once again, it was fine before the new tires.

Who would have thought that buying new tires would have turned into such a #*&$#% ordeal! Sooooo frustrated!! You'd think I could go two months with this car without a problem. And the worst thing is....there shouldn't be a problem! I just bought tires for goodness sakes!

Sorry for the venting.

[jdd]

Another thing to be aware of is that most (all ?) modern wheel balancing machines need to be calibrated. They can, and do go out of calibration.
Also, it’s critical the operator of the balancer knows what they’re doing and exactly the size of rim they are dealing with.

My money is still on either a defective tyre or wheels that are just plain out of balance.
My experience with tyre places is that they usually have one guy that knows how to balance all wheels correctly and the others know how to balance some wheels correctly.
Wheels that don’t have any weights on the outside can be tricky to balance if you haven’t been shown how to do this correctly.
I would see if you can find a reputable independent tyre place to check the balance on at least the front two wheels.
Another suggestion is that you find a place that can balance the wheels while they are still on the car (just as a check, not to balance). This is how they do many trucks, and it might show up other issues such as the rim not sitting on the hub correctly.

[TowX]

If you don't mind my asking- did you buy the tires from one of those chain stores or from a dedicated tire shop?

jdd has offered two great pieces of advice in his posts.

First, modern tire machines can make the wheel/tire "zero" out, meaning it'll tell the operator where to put the weights and get a "perfect" reading. But that doesn't mean the tire or wheel is round, just balanced. I've seen badly bent wheels balanced so the machine read all zeros, but it was still bent. Heck on one I'd seen the tire machine was shaking because the wheel was so bent, but it read all zeros. And it'll shake like crazy on the car.

Second, good shops constantly have their machines recalibrated. The shop that does all my work (2 sets of wheels for each BMW, 4 sets for the race car, fresh wheels and tires on the trailer) has one machine just for car alloys. They use their other three machines for SUV wheels and other wheels and tires. Big heavy SUV wheels and tires easily throw machines out of calibration.

Finally- the only way to properly tell if you have a wheel or tire problem is to have all 4 run on a Hunter Road Force 9700 machine. I places a load resembling driving on the street against the tire and spins it. Measures imperfections in the wheel and the tire, but requires that the operator know what they're doing.

BTW- several years ago I had 17" Conti Contact A/S tires on my 528. My tire shop went through 7 tires over a week to get 4 good ones that weren't out of round. Manager said he was seeing that a lot with the continental all season performance tires, to the point he told his staff not to offer them to customers any more.