I just cannot seem to figure this out - nor can the techs that have looked at my car.

1999 Bonneville SLE, 150k, new front struts, new cv half shafts both sides, all other front suspension components either replaced (stabilizer pins, ball joints, etc.) or determined (by techs) to be ok.

Can has been aligned; tires balanced with about 20k on the tires. Tracks perfectly straight at speed.

When I am at low speeds such as moving through a parking lot, if I hit a small bump, pot hole or expansion strip in the pavement I can feel a pronounced vibration in the steering wheel and what also feels to be in the floor pan. It seems to me to be a problem with the driver side suspension.

Traveling at higher speeds (i.e more than 30 mph) the problem is not evident. I do get what feels like some rotor pulsation at over 40mph, or what feels like it. No pulsation at lower speeds.

It almost feels like a loose strut or a bad cv with a lot of play. All struts and half shafts were replaced and did not resolve the problem

Could I have a bad hub that would cause this? They are just about the only components that haven't been replaced. No humming coming from any of the bearings that I can detect. Very annoying problem that has me at wits end. Your help and suggestions greatly appreciated....

Reading your post, there'* clearly something a little off and the normal diagnosis is failing.

Have your subframe bushings and motor mounts been checked? The subframe bushings are about the age where they may allow some shifting which could cause oddness at certain times. The motor mounts, main rear trans mount and passenger side body/TA mount would be the ones I'd check over.

The transaxle was replaced about a year ago, so for me that'* about 15k. I would assume (ha ha) that the trans mounts were replaced but we all know how that goes. I'll focus on the mounts/bushings and ask the techs to take a look this weekend when I get a tire rotation. A different tech may pick up on something the others have not. Engine is nice and tight when I rev in drive with the brake on but that test is never absolute.

I had pretty much the same vibration but mine was on the passenger side and after changing all of the things you changed and more I put the car on jack stands and had someone run the car at different speeds and all I could see move was the right motor mount and after I changed that the vibration is gone so good luck and hope if you look at the left motor mount that would help you.

Good way to check engine mount is to get a buddy'* help. Have you buddy hold the foot brake (and parking park on for safety) Put the car in drive and torque up the engine. Watch for exesive movement or broken mounts. The popular one to break is the driver side front trans mount.

have you had the steering rack checked . could be bad internal or the two rubber mounts on it could be bad. check the dog bone on the bottm back of engine

Will be checking the rack over the holiday weekend. Techs could not find anything. Mounts, bushings and all suspension components checked out fine. Funny thing, though, is that when the car first comes down off the rack and the suspension hasn't settled back down yet I do not get the vibration. After I drive it a bit and everything settles out it comes back. So it appears that the angles present off the lift mask the problem for a while. I also checked the top nut on the struts to make sure they were tight (they were) and also made sure the bearing plate nuts were tight as well. Pulled the air cleaner box out to look down there, did not come up with anything. As 99BonnevilleGreen suggests, maybe the rack is loose internally. That is about the only thing left to check.