The problem:

The car drives great, smooth and straight, but the steering does not self center after a turn. Now, I know what you're thinking: CASTER!! But, unfortunately the problem is, apparently, not so simple.

I have had two top-notch alignments, one of which I worked very closely with, even tried adding 4 degrees more caster (or maybe it was less, I forget) than factory specs, and the steering still does not self center. It drives well, doesn't pull one way or the other, but the wheel simply stays exactly where you put it.

It was suggested, and quickly discounted, that the steering box may be set up too tightly, but after a quick adjustment we found that this was not the problem either.

One of the alignment shops told me that there are two adjustments on the power steering valve: one which adjusts the left and right power flow, and one which adjusts the pressure on the ball joint. They were thinking that the problem may lie in the adjustment of the pressure on the ball joint.

Not being a fan of working on these power control valves, I just wanted to make sure that this is a correct hypothesis before devoting a weekend of oily work to a wild goose chase.

Oh, some background info:

Steering box has not been replaced or tampered with, other than the adjustment at the alignment shop.

All tie rod ends are new (do they need broken in?)

Power steering valve is a rebuild unit from zip corvettes

All A-arm bushings are new, though the shop that pressed them in suspected that one of the bushings may not have belonged to this set, because it fit slightly loose compared to the others. We reasoned that as long as it made a snug fit when tightened down that it shouldn't be a problem.


All thoughts are appreciated!!!

 

Yes, you need to adjust the steering valve to center it. Make very small changes-less than a 1/4 turn at a time. It doesn't take much. Jack the car up in front, remove the end cap on the valve, start car, adjust the valve until the tires center.

 

Here is a page or two on our site that will tell you how to adjust the valve properly.

http://willcoxcorvette.com/repairand...lp.php?hID=188

Willcox

 

I'll go over the adjustment again just to make sure. To be honest, I am skeptical that it will solve the problem because it doesn't want to turn right or left, but i will go over it...maybe even today, and share the results.

 

3. With the valve balanced, it should be possible to move the cylinder rod in and out manually.

I just checked this function, and as long as this is the goal (to be able to move the valve in or out with the engine running) then its adjusted correctly.

 

Depending on how the lash on the box was set that could be a part, or the problem. The correct way is to use a 0-30 in/Lb dial TW with the box out of the car. There is an in the car procedure as well, I believe Jim Shea has it in his paperwork. A lot of time the lash screw is turned in without regard to on center position or increased drag. The steering will tighten up while at the same time putting undue wear on the center tooth and possibly causing an on-center bind.

 

You beat me to it, GTR... If you [or a PO] overly tightened the steering box lash adjustment, you would get the same symptoms. If the steering has no 'play' in it now, just mark where the adjustment screw slot is positioned, back off the lock nut (just a bit to loosen it), then turn the slot 1/4 turn CCW from where it was when locked down. Hold set screw in place with screwdriver while locking nut again and drive the car to see how it responds. If the wheel centers-up OK and the free-play is satisfactory, you should be good to go. As GTR mentioned, the proper way to set it is with the unit on a bench and the lash adjustment set with a small torque-wrench. If in doubt, take it to a qualified repair person.

 

Hi

can someone tell me how to set the steering box. I just had a remanufactured one installed and everything is about 10x worse than the old one. I tightened the lash adjustment all the way and still not good. of course it hardly self centers now because it is so tight but otherwise it as so much 'play' you can hardly drive, a whole hand width easily(I am still wondering how it passed technical inspection..) but i didn't check the pitman arm if this is not wobbling. any ideas?
thanks

 

PM me and I'll get you the link.

 

http://jimshea.corvettefaq.com/?page_id=4