DonnieP73

My 73 has power steering. I have replaced the pump, control valve(new), and cylinder.
The problem I have is the front end will began to shake back and forth uncontrolable until I stop or kill engine.
This is not a front end problem as it has been aligned, all joints are tight, the steering box has been rebuilt.
I don't have to hit a pothole or bump and can be steering straight when this happens. I have placed the vette on jack stands and
double checked for air and tightened all hose connections. When turning the wheels back and forth, the shimmy can start at anytime
with the wheels in the air. The only way to stop it is to kill the engine.
Now for the question:
Has anyone experienced this behavior with their power steering and if so, was the problem with the pump or control valve? I can start replacing parts
again, but would rather find out if anyone has had this happen to them.

I thank anyone for their experience and advise.

Donnie

GUSTO14

Check out posts #6 & #7 here...
https://www.corvetteforum.com/forums...e-balance.html

You can also go here and download Jim Shea's paper; REPLACING AND BALANCING THE POWER STEERING CONTROL VALVE
Jim is the resident guru on Corvette steering systems.

Good luck... GUSTO

DonnieP73

Thanks for the reply, but this is not the control valve unbalanced.
This happened almost a year after all the above were replaced and
the steering is straight and turns easy. This happens at random times
that the the front wheels shimmy and may turn the wheels on the jacks off
the ground lock to lock several times before this occurs.
Have followed Jim's directions to bleed air out of system and there is no
air present when this occurs.
Again, thanks for your input.

Donnie

Haggisbash

My pick would be a control valve issue. Have you tried disconnecting the ram from the chassis when you have the wheels off the ground to see what it does when you have the engine running and turn the steering?

lvmyvt76

idler arm???

BLUE1972

I would look at the control valve.

It can also be a bad seal internally in the cylinder.

I would change the fluid and then I would look at the control valve first . If there is no change.

It does sound like the valve can't find center. Which could be dirt or an internal problem in the valve.

DonnieP73

Thanks Blue1972,
I think you are on the right track. I had some time this afternoon
and just thought I would check the fluid. I pulled the fluid out of the pump reservoir
and it was black. Tomorrow I will flush the system completely and see if that
solves the problem. If not, I am going to replace the control valve.
Thanks again for your insight.

Donnie

DonnieP73

Thought I would give an update.

I checked everything and all was good and tight. Had another shop that
specializes in classic and sport car alignment that set alignment to
exact specs. While there, they started up and turned wheels back and
forth. Found problem, the power steering cylinder was not tight on the
tie rod and was allowing movement like bad tie rod. Tightened cylinder
up and all problems gone. Could only see the movement with the power
steering moving. There was no movement you could tell otherwise.
Thanks for all the suggestions.

Donnie