Mysterious front end shake at speed

[Jerry Clayton]

OK Steve----I think the verbage led you to reaD THAT i MEANT THE DESIGN WAS BAD(sorry about the caps lock)

Here's where I am pointing the finger---A RAG JOINT won't fix the PROBLEM!!! neither will tightening up the adjustment of the rack( Sorry Blas)

The shake is coming from something that can generate a force back thru the steering parts---this can be from wheel balance, out of round, etc---it also can come from caster, ball joint to tire patch alignment, etc----

There are systimatic processes to determine when it does it( 60-85 mph)---is that in a straight line??? how about a long turn to the left??? right??? under braking???these are just some basic examples of ways to isolate this vibration/shake---

In addition to all the suspension sources for shake/vibs---aero can play a big part at those speeds---a small panel can cause enough buffet to shake a 2-3000 lb car---

[Blas]

While some people may have different or additional steering issues...
Over the years the people (Owners of SPF's, VW's, etc) who have adjusted their rack adjustment bolt and have had success with this issue and had no additional problems since. It's a cheap and easy thing to try...and has worked for many in the past. It's a internal wear issue on the nylon washer.
Perhaps if you substitute the word "adjusting" for the word "tightening" this will suffice.

[jhv48]

I've got SPF 2932 and I had a front end shimmy that was only solved by balancing the wheels and tires while they were on the car. The vibration does return when the car has been sitting on the cold cement. It disappears after a few miles or if the weather is hot. Thus, I think the tires are flat spotting. Nothing to do about that except to buy some tire cradles so that they never sit flat on the garage floor. I did adjust the steering as suggested just now. Will let you know if this helped any. Also checked the caliper bolts. I could barely turn all of them. Obviously they had no lok tite but they were pretty tight. I have 7500 miles on my car so, I'm not that concerned.

[SCARRY]

BLAS has a good point if there is clearance between the rack bar and pinion gear then the wheels are free to move due to the free play. The adjustment is there to push the rack bar against the pinion so that there is no play. Normaly there is a spring or a spring washer to help with maintaining the lash. Not sure if ours have that.
One other thing that I found on my car is the I Shaft joint to the steering column shaft was not tight. The bolt was tight but I could move the shaft in the splined U Joint. I did tighten mine up and I do not have the issues that are mentioned. I also have my origonal BFG's and the original balance. The car is a 2003 SPF.

[jhv48]

I just tried the adjustment on the rack and pinion. It did tighten up the steering a bit and feels much more solid and smoother now.

Thanks for the suggestion, Blas.