My 951 has a severe knocking from the front of the car, when I hit 70mph, 82mph, and 89mph. I really sounds like something is about to shake apart, so I have not been able to get my boost fix lately.

I checked the front inner and outer roller bearings and it dont appear to be that. I think I narrowed the source of the shaking form either a blister or bump
inside the front passenger tire, or the strut itself. I also noted the driver side strut bearing support is lower than the passenger side. Also, the passenger side has slight negative camber, and pulls annoyingly to the right. Will a four wheel alignment correct this problem, or do I have to rpelace both struts?

 

Let's start with the obvious; miles on the car? Have you checked:

Ball joints
Tie rod assemblies (check for loose joints inside the protective boots)
Caster block bushings (these hold the back of the control arms to the chassis)

Any of these items been replaced recently?

 

Ball joints are fine. The driver side tie rod was bent 45degrees and was recently replaced. I am not certain if the control arm caster block eccentrics have ever been changed, though. The large washer above the strut rod on hte passenger side appears to be not in symmetry with the driver side- which I believe is correct.

 

Check the wheel-bearings, and the struts.

 

Could also be a bent rim.....

 

I had a simmilar problem with the Turbo when I took it out the first time. I thought it was the bearings because the wheel had play in it. Turned out that the retaining nut had just backed off about 1/2 turn. Tightened up both front nuts and its been fine ever since.

Also, had a problem with bumps in the tires. It had been sitting so long I guess the tires got flat spots. It would bump like crazy at 60mph but would go away above or below that. Drove it on a 300 mile trip and the tires rounded out by the time I got there. Again, fine ever since.