Front vibration through steering

[Cloudsurfer]

So, several weeks ago I hit some debris on the highway on a rainy night (still shocked I didn't see whatever it is, but hey) that was significant enough to crack the bumper and take a chunk out of the left front wheel. So, as I was kinda looking for new wheels anyway, we wound up with a set of BBS RSIIs now. Next, we replaced the lower control arm and outer tie rod, since they had some play in them, and installed the full RoW M030 suspension. New Contisport 3's went on with the wheels.

Now, after all that, I STILL have a slight vibration that can only be felt through the steering that comes in between about 65-75 and then returns after about 85, varying in severity depending upon road speed.

Anybody have any insight as to what to look for next? This is driving me nuts! One would think the alignment rack would catch anything bent or out of spec, but the #s are perfect, so apparently not

Input much appreciated.

Patrick

[Lil bastard]

Almost all vibrations are to be found in the wheels or tires. How were the tires mounted and balanced? Road Force balanced using a Hunter 97XX machine? Where were the tires purchased, locally or online? What did the Hunter machine print out about the tires being out-of-round (they ALL are to some degree, but must be within a certain tolerance in order to be balanced properly).

There could be other causes of what you're experiencing, but I'd be surprised in the answer doesn't lie in the tires/wheels.

[RandallNeighbour]

I've battled wheel and body vibration in my boxster since I bought it. New tires fixed the problem twice, so I'd definitely agree with LB on this one.

If you did use a Hunter 9700 series machine to road force balance the wheels, I'd take it back and ask them to do it again and recheck their work.

Sometimes the weights should be put further toward the outside or inside of the rim to be in perfect balance, so ensure they are dynamically balancing them as well as road force balancing them.

[Cloudsurfer]

Balance checks, and yes to the Hunter. What's concerning me is the possibility of damage to the hub/ bearing/ carrier assembly from hitting whatever it was that I hit. Short of swapping it all out and going for a drive to see if that cures the problem, anyone else have any ideas? I'd hate to replace all that if it didn't need to be. I suppose a bad bearing is a possibility as well.

Other than that, what else is there to blame?

Patrick

[Lil bastard]

Next thing I'd check is a bent suspension member such as a Control Arm. These are alloy and would likely show some 'scars' after hitting some debris.

[Cloudsurfer]

Already replaced the control arm and outer tie rod ends (both sides). I find it hard to believe, but I really am leaning to thinking there is damage to the hub/ hub carrier/ bearing.

Patrick

[BYprodriver]

When you say you wound up with a set of BBS wheels that sounds like you did not buy them new. That makes me think it may be the front wheel may be bent. Also you can always get a shimmy from the steering wheel if you put enough air PSI in the front tires. Always spinup wheels on a tire balancer to see how out of balance they are before mounting a tire on them.

[Cloudsurfer]

BBS wheels were purchased new, and they have been spun on a Hunter DSP and are about as true as wheels get. The problem was solved by using the Road Force balancer to re-mount the tires (all 4) to get the lowest road force. All are under 10 pounds now and things are perfect.

Patrick