steering not balanced

[Frederick W.]

My 63 coupe with factory power steering has an odd problem. When turning left, the car turns more easily than when turning right. It seems unbalanced and wants to "jump" into a left turn, often resulting in oversteer. Right turns are not like this.
?power steering valve
thoughts?

tia
Fred

[Jack H.]

Re: steering not balanced

Two thoughts come to mind:

(1) Was the 'over center' adjustment made properly?

(2) Is the PS control valve a correct 'Corvette' unit vs. a generic Chevy passenger car assy? The two differ in terms of internal components (springs) and use of a passenger car valve in a Corvette application is known to result in a 'twitchy' PS response profile...

[Duke W.]

Re: steering not balanced

...possible toe problem at the rear. Toe-out on the right side could cause this problem. Total rear toe with radial tires should be about 1/16" toe-in divided equally between both sides.

The best way to verify is to get the car on a modern four-wheel alignment rack, but you can use a tape measure to get an idea of total toe-in. This won't tell you if it's equally divided, but if the total is not between zero and 1/8" toe-in, it's definitely not correct.

There are a lot of C2/3s out there with totally messed up rear toe settings.

Duke

[Frederick W.]

Re: steering not balanced

Excellent advice, gentlemen, thank you.
Jack, when you say "over-center adjustment" I take that to mean indexing the steering wheel and column to have the steering gear on it's high center when the wheels are straight ahead?

I'll check the indexing, and toe in today.
Any way to know whether my power steering valve is a corvette unit?

Fred

[John H.]

Re: steering not balanced

Fred -

I'd focus on the rear toe-in settings and loose/missing shims.

If the P/S control valve wasn't balanced, the steering would pull constantly to one side or the other.

The Corvette control valve has a 55# centering spring in it (requires more steering torque to activate boost), and originals had an "X" stamped on the end cap; the Chevy II valve had a 30# spring, with a "C" on the end cap. I think many of the valve rebuilders either don't know that or ignore it.

[Frederick W.]

Re: steering not balanced

Fred -

I'd focus on the rear toe-in settings and loose/missing shims.

If the P/S control valve wasn't balanced, the steering would pull constantly to one side or the other.

The Corvette control valve has a 55# centering spring in it (requires more steering torque to activate boost), and originals had an "X" stamped on the end cap; the Chevy II valve had a 30# spring, with a "C" on the end cap. I think many of the valve rebuilders either don't know that or ignore it.

Thanks John,

what you say makes sense to me.
I did a crude measurement with a tape measure and it looks like I have too much toe in, over 1/2 inch difference in the track width with front of tire vs. rear of tire measurement. Presumably, it's not equal. I guess I'll need to get it checked out at an alignment shop.

Of course, I know of no dedicated alignment shops in my area, mostly just tire stores and tune up shops advertise alignment.
Maybe the Chevrolet dealer would be the best option?

BTW, to set toe I assume you have to remove the trailing arm bolt to adjust shims? If so this could be a problem...

Fred

[John H.]

Re: steering not balanced

Maybe the Chevrolet dealer would be the best option?

BTW, to set toe I assume you have to remove the trailing arm bolt to adjust shims? If so this could be a problem...

Fred

Fred -

A Chevy dealer might be your best bet, unless local NCRS or Corvette Club members recommend a shop. The trailing arm bolts will have to come out to set rear toe if you have the original "hole" shims (vs. the later "slot" shims). I'd expect a Time & Material job rather than a flat quote.

[Frederick W.]

Re: steering not balanced

Fred -

A Chevy dealer might be your best bet, unless local NCRS or Corvette Club members recommend a shop. The trailing arm bolts will have to come out to set rear toe if you have the original "hole" shims (vs. the later "slot" shims). I'd expect a Time & Material job rather than a flat quote.

[John H.]

Re: steering not balanced

John,
What do you think about this procedure (from the Duntov Motors "tech tips" on their website). Alan Sevadjian and his team are a pretty experienced bunch. Maybe I should just set it myself:

Fred -

I'd take it to a shop that knows Corvettes; you may encounter significant grief removing the pivot bolts.