The power steering on my 1976 Corvette is too sensitive. This is nice if driving the posted speed limit in town. However, the faster the speed the more pronounce the steering response is resulting in it being dangerous especially when entering a curve. After a wreck in 2015 resulting in damage to the driver side of the vehicle around the door area and the rear wheel assembly and suspension. Since there was damage to the suspension resulting in it needing to be replaced, I had coilovers with adjustable QA1 shocks, front and rear, and tubular A-arms installed. I immediately noticed the sensitive steering but assumed this was a result of the upgraded suspension and tubular a-arms, and that I would get use to it. That has not happened, and I've had other people drive it and they thought it was even dangerous. I've had the alignment done several times with the last time involving the tech guy from Van Steel, the company providing the coilovers, shocks, and a-arms, instructing the alignment guy how to do the specific alignment required for this setup, and this did not correct the problem. I've also had several people examine the front end components, and they are okay. I've taken the car to several shops and no one has an answer to this problem. The only thing that has done some help in reducing the sensitivity is moving the tie rods from the power to the manual steering connection holes. The other component that affects steering is the steering box, but I don't see how this would be affected by the wreck, and it would seem a worn or damage steering box would have the opposite affect....loose steering. I have considered installing a Borgeson Corvette power steering box, but worry this might make the problem worse since this is usually done when steering is loose. I've put up with this condition for several years, but it would be nice to do some spirited driving without worrying about managing the next curve.

I would appreciate any and all comments/advise.

 

Tried lower tire air pressures?

 

There are ways to change the power steering pump flow or pressure. Or you can just convert it to manual steering.

 

What were the results of your wheel alinement? How much caster did they give it?

 

It would be helpful to see what the front Toe and the Caster settings are, as well as the rear Toe setting.
Additional caster in the front end and more Toe-In for the the rear trailing arms will both help with the high-speed stability.

-Chris

 

Sounds strange if Van Steel was involved that there would be an issue with the alignment.
That said, I did 2 four wheel alignments with (me helping) professionals. since then, I do all my own alignments.
And Damn, my car tracks nice. Holds a line in a sharp downhill hairpin, tracks nice at high speed. Etc.
Yes, What exactly are your alignment settings?
You really shouldn't need to have power steering hooked up to manual steering holes.
Something is definitely wrong.
Me, I would go back to Van Steel and explain your problem.

 

My 77 had this same problem. I put up with it for years and just lowered the front tire pressure to deal with it. Then one day my power steering control valve started leaking and I needed to rebuild it.
Turns out it was the power steering control valve creating this situation.
I've attached a video for rebuilding the power steering control valve. In the video he talks about a "piston" at about 6:12 into the video. This piston slides into a larger "piston", @ 7:06, when the two halves of the control unit are put together with the spring ending up inside the larger piston.
When I took mine apart for the first time the little piston was jammed into the larger piston with the spring inside. I didn't even know they came apart. Some time during the night it came un-jammed and the little one shot out across the room. So pretty good pressure from that spring when it's fully compressed.

I believe, looking at the mechanics of the valve, that the little piston with spring inside the larger piston acts as a sort of shock absorber when the steering is deflected. So that the hydraulic fluid doesn't hammer or overreact to the drivers input. Minus this small shock absorber the valve over reacts giving you the hyper sensitive steering.

I came to this conclusion after the rebuild and my power steering was no longer over sensitive. Hope this helps.

 

I appreciate all the comments/suggestions I have received on this thread. I have replaced the steering control valve and rag joint, installed a Borgeson Universal Power Steering Pressure-Reduction Kit reducing the original pressure(I believe about 1350) to 1,000, and had the guy from Van Steel on the phone with the alignment guy during the alignment to ensure the correct alignment for this suspension system. Van Steel instructs the buyer of this suspension system to call them before getting an alignment as it requires a specific alignment. So, this was done. I've talked to Van Steel several times about the problem and they have indicated this problem has never been encountered with this suspension. I had the Van Steel suspension installed during the repairs for a wreck, so I've often wondered if the problem is the result of the damaged caused by the wreck or the new suspension system, but as previously stated, I've had several shops inspect the front end components and no problems were found. I have not tried reducing the air pressure on the front tires. What pressure is recommended? I keep my air pressure at 32 on all the tires. Again, thanks to all of you for your comments/suggestions. I would not have a problem if I would just drive the posted speed limit, but what Corvette owner wants to do that.

 

Even now I run front tires @ 24 to 26 psi.

 

What I don't understand is I did not have this problem prior to the wreck and installation of the Van Steel suspension system, so it would seem the problem is with the damaged from the wreck or the suspension system or maybe both. What I didn't mention previously, due to the damaged to the driver's side rear wheel assembly, both complete rear wheel assemblies were replaced along with the sway bar. I'm out of ideas of what to do to correct the problem. Although I was using 32 psi in all the tires prior to the wreck, and since I've tried the other methods I mentioned, I will reduce the front tire psi to 24-26, and hope this simple solution works. I've had this car since May 2010, and I don't let it set in the garage. I drive it every weekend, except when there is rainy weather, and I've taken it on two 4,000 miles trips to California, Utah, and Colorado along with a 2400 mile trip to Colorado. It has a ZZ4 crate engine hooked to a 700R4 transmission. It is truly a restomod.

 

Can you please post the results from your wheel alinement? I assume they gave you the before and after printout?

 

sorry for your troubles.
there is a lot going on in your experiences and mods.

I am leaning to a rear end problem at this point.

Hard to really understand what you are feeling when you drive or understand your description.

The company that made the coil overs and parts is a good one.

Check half shafts for being parallel to the ground, frame height to the ground, anti sway bar for installation and binding.

hope you get it sorta.

 

The alignment was done early with the Van Steer rep on the phone, and was checked 12/01/20.

 

As I was putting up my paper work, I noticed the front left SAI and Included Angle were 22.3, and 22.4, respectively, as apposed to the front right SAI and Included Angle being 7.1. This can not be correct. Thursday I will take it back to the shop and ask about this alignment.

 

me too.. love it.. look at door decal OP.. i run optional 24 and 28 2 psi above door..not worried about fuel economy..

yes i am aware of old recommendations but it works for me..p metric radials were around in 79 too.

 

No one can say that you don't have enough caster, which would have been my first guess.

Converting my 79 to Borgeson steering removed the floating on a rail feeling that made the car unpleasant to drive before.

One experiment to consider would be to remove the power steering belt. The steering valve will be loose without fluid pressure, and sttering very stiff with 7 degrees of caster, but then you'll be able to see if your problem is alignment or power steering. Perhaps ask Van Steel if they think this is a good idea.

 

Have you checked that the steering box input shaft is at the correct position when the wheels are pointing straight ahead?

 

Two things I noted.
1) The front toe is at the minimal end of the range. You should be able to increase the front toe in a bit and that would help the car be less sensitive. (I had shop give me some toe out and the car wanted to dart everywhere).
2) Rear toe needs to be redone. Driver rear is toed out and passenger rear has lots of toe in. Total is in range but you really want the toe balanced across the rear wheels. Definitely important on our cars.

 

I haven't driven the car since reducing the front tire psi to 26, but will be going to my mechanic tomorrow to ask about the front left SAI and Included Angle, and the rear toe in. I have contacted Van Steel again and sent the latest alignment specs, and ask them to evaluate and let me know what they think. I can't remove the power steering belt as I have converted to a GM serpentine system. In regards to the steering box input shaft being at the correct position when the wheels are pointing straight ahead, I will ask my mechanic about this issue. I'm hopping Van Steel will get back to me today before to go to my mechanic tomorrow.

 

The reason I ask about the steering box input shaft is that if the car has been aligned with the the steering box input shaft off centre the steering will feel weird even if the alignment is correct. The steering box is engineered with a tight spot at the straight ahead position, have look at the pic in the Jim Shea steering paper I've attached, you can check if things are correct very quickly yourself. You have a decent amount of caster (about the same as a C4 or later Vette I think) caster wash my initial thought of what your problem might be. Have you driven another C3 to compare steering?