67 Power Steering issues

[Donald H.]

I'm helping a friend try to diagnose how to address an issue with his power steering.

His 67 big block was converted to power steering. He did not do the work himself, and I don't know anything about the system that was installed. From the few power steering system that I have seen, his assembly looks similar to the OEM system, but I suspect it is all aftermarket parts.

His issue is that at low speeds, the power assist is almost nonexistent, and at high speed the assist is so much that driving the car is not fun.

I've looked at the service manual and searched the TDB and found lots of thread regarding the control valve adjustment and centering. That doesn't seem to be related to his problem, but given that neither of us know much about the power steering, I could be wrong.

Could it simply be a bad control valve? I see lots of them listed on Ebay and elsewhere for under $200.

Any suggestions are welcome.

Thanks,
DOn

[Gerard F.]

Re: 67 Power Steering issues

Don,

Just a thought. Maybe the linkage to the spindle is in the wrong hole, It should be in the forward hole.

I have had the same problem with my 67 S/B. Did an add-on OEM system and attached the linkage to the rear hole in the spindle. Was all over the road at high speed.

Also a front end alignment might help. increased caster.

[Greg H.]

Re: 67 Power Steering issues

Hi Don,

When I converted my 67 small block to power steering I purchased a complete assembly at a swap meet and had the same driving sensation you are describing. At speed, the steering would over steer and was too sensitive to be comfortable. The parts were from a C3 and the problem was the pressure spring that is inside the control valve. C2 Corvettes require a specific pressure spring that was used on Corvettes only. Lonestar will have the spring you need and the rating is listed in the 67-repair manual.

Also, I agree with Jerry, check the location of your out side tie rods, they maybe in the quick steer locations.

[Donald H.]

Re: 67 Power Steering issues

Thanks guys, I'll check the tie rods and suggest he order a new spring from Lonestar.

[Greg H.]

Re: 67 Power Steering issues

Tie rod location for power steering. I will look for my photos of my rebuild tomorrow. I may have a comparison shot of the two different springs. Changing that spring was the key for my fix.

[Donald H.]

Re: 67 Power Steering issues

Greg,

In looking at the exploded view of the control valve in the Overhaul Manual, there are two springs. There is a Valve Adjustment Spring and a Valve Spring.

I assume the one that may need changing is the Valve Spring.

Thanks,

Don

[Greg H.]

Re: 67 Power Steering issues

Yes it's #8 in the exploded view Valve Adjustment Spring it's about 1" tall with tight coils. On page 9-25 you will see the note that sets it's rating at 55 lbs. and all others were at 35 lbs.

[Greg H.]

Re: 67 Power Steering issues

Hi Don,
Found my old photos. Hope this helps.