vibration at highway speeds

[rh71]

I got my replica 20s on and only when traveling above 60mph on the highway do I notice a vibration. I didn't notice in a week of local driving because I don't take highways much. The vibration is not on the steering wheel, but you can see the passenger seat shaking a bit and definitely feel it in the driver's as well. It is more pronounced if I let off the gas and just cruise.

It feels perfect and non-existant on local roads and anything below 50mph or so.

The tires are still pretty new and have the little tiny pegs that are supposed to wear off. I was hoping this was the cause but it doesn't seem likely and the vibration is pretty bad (seeing the seat shake is not a good sign). I can bring it back to the guys who mounted/balanced it but I'd like to have some idea beforehand. Why does it vibrate only in this scenario? Are those tiny weights (which they've used plenty of) the only solution probably? Is that what's done for balancing?

[mrbmwx5]

your tire may need a balance

[genew]

Originally Posted by rh71

I got my replica 20s on and only when traveling above 60mph on the highway do I notice a vibration. I didn't notice in a week of local driving because I don't take highways much. The vibration is not on the steering wheel, but you can see the passenger seat shaking a bit and definitely feel it in the driver's as well. It is more pronounced if I let off the gas and just cruise.

It feels perfect and non-existant on local roads and anything below 50mph or so.

The tires are still pretty new and have the little tiny pegs that are supposed to wear off. I was hoping this was the cause but it doesn't seem likely and the vibration is pretty bad (seeing the seat shake is not a good sign). I can bring it back to the guys who mounted/balanced it but I'd like to have some idea beforehand. Why does it vibrate only in this scenario? Are those tiny weights (which they've used plenty of) the only solution probably? Is that what's done for balancing?

Whoever sold you the wheels and tires didn't do a good job of balancing.
The other possibility is that one of your wheels might be out of round and not able to balance with weights. Go back and complain.

[HaroldC]

Your rear tires/wheels are out of balance. If it was the front tires/wheels, then the steering wheel would shake, but it doesn't so logically it must be your rears.

You need to get them rebalanced, preferrable on a road-force machine. BMW dealerships usually have the Hunter balancers with road-force, as do a ton of local tire installers. Call around, there's plenty around.

Worse-case senario, you have an out-of-round wheel or tire. That would be determined on a balancer, so you never know until it's rotating on the machine.

Good luck.

[rh71]

Well when I brought them the 4 replica rims, they supposedly spun them all and found 1 out of round (a front one because it was 10" width and not 11"). I got it replaced... those are the fronts. Hard to believe a rear was out of round and they didn't detect it when they detected the front one at the time. If it really is out of round, I'm gonna be stuck with it as it's already mounted... would not make for a very good day. Hopefully it's just a balance issue.

- is there usually a work-warranty period? I didn't see it on the receipt.
- would tire pressures (they're actually maxed 44psi right now) have anything to do with vibration?

[mrbmwx5]

- is there usually a work-warranty period? I didn't see it on the receipt.
- would tire pressures (they're actually maxed 44psi right now) have anything to do with vibration?[/quote]

too much air will make the tire (dancing with the star.)

33psi all i used.

[genew]

Tire pressure would have no effect on balance, just how the tire wears. I don't think it makes any difference as to a week or so on an out of round wheel. They should stand behind it unless it shows where it was damaged by a curb or pothole.

[judd]

I have no vibration at all on summer or winter tires at 100 mph. Sounds like yours need balancing. Both are BMW OEM so maybe that's a difference? Wouldn't expect it though.

[nynd]

Also - you may want to see which tires you mounted. If the vibration is there at the on start and then goes away, it is possible that the tires are flatspotting (I had this once - crappy tires). The other issue is that you will want to see how they were balanced - from the mounting studs or the center hub. If it was from the hub, have them re-do it with a wheel stud attachment or go to another shop. Another quick thing you can do is rotate the rears to the front and see if the vibration travels to the steering wheel. You could ideally even move one at a time and see which one is creating the issue. Like previously mentioned - you have an out of round rim which cannot be balanced.