Alignment woes, again...

**Timothy B.** · April 18, 2007, 03:24 PM

Re: Alignment woes, again...

Forgot to mention: All components are fairly new in the steering and suspension system front and rear. No worn bushings, tie rod ends, idler arm, rag joint, etc. Everything has been checked and is tight.

**Terry F.** · April 18, 2007, 03:31 PM

Re: Alignment woes, again...

Do you feel as though you can't feel the road back through the steering (feedback).

I say this because the over haul manual describes a flow regulator being use in my 68 manual in the pump. Regular passenger cars don't have it or shouldn't have it. Without it, it might make your car feel twitchy.

Just a thought, Terry

**Duke W.** · April 18, 2007, 03:54 PM

Re: Alignment woes, again...

It would help if you would post the complete front and rear alignment data from the last alignment. Shops should give you a computer printout with all the final measured settings. The ride height should be checked prior to alignment and corrected if necessary. The procedure as outlined in the CSM and AIM is easy (You can do it on your garage floor.), though the front measurement is a little tricky because it's tough to eyeball the center of the lower ball joint.

Also, what cold tire pressure are you running?

If you say the car is "bouncing around" then your shock absorbers are may be bad or by design don't have sufficient reabound damping. Most replacement shocks are limp when new. Bad shocks that allow the car to wallow around will result in poor handling whatever the aligment settings. The C2 suspension has a lot of camber and toe change with wheel travel, so good damping is a must or they can be a handful.

I don't like cars of the era with power steering. All, including Corvettes were overboosted and numb. With good tires, alignment, shocks, and everything else in the suspension in good working order, manual steering feel and handling is very good for a 45 year old design.

Modern cars, nearly all of which have power steering, typically have caster specs in the plus 5-10 degree range, which give decent feel at long as the steering is not completely overboosted and most aren't.

Duke

**Gerard F.** · April 18, 2007, 05:48 PM

Re: Alignment woes, again...

Tim,

Have you got the tie rods connected to the forward lug holes on the wheel spindles (for a faster steering ratio). I know it sounds crazy but the forward holes are for power steering and the rear for manual.

I had them on the rear holes with power steering on my 67 and was all over the road at high speed. Switched to the forward and resolved the problem.
Still a little sensitive at high speeds on curvey roads, but you get used to it.

Take a look at this post from a few years ago.

https://www.ncrs.org/forum/archive18.cgi?review=137227

Regards,

Jerry Fuccillo
#42179

**Terry F.** · April 18, 2007, 08:48 PM

Re: Alignment woes, again...

Also, if the rear end isn't set right, it will contribute to the twitchiness. Needs to be adjusted to track the front and make if comfortable to drive. Terry

**KEN BUTCHER** · April 18, 2007, 08:57 PM

maybe it's just a worn steeringbox??? *NM*

**Terry F.** · April 18, 2007, 09:04 PM

Re: maybe it's just a worn steeringbox???

You might be right or even one that is not set up correctly. Too loose or too tight and not good. Sometimes, it they go dry and get rusty, the one bearing can go bad on the worm shaft and cause all sorts of funny play (be easy on me, it has been a while since I was motivated to take one apart). I once took a worn out steering box and tighten it up with the adjusting screw. Made if feel worse real fast. That adjusting screw is basicly only good for when the box is originally set up. Beyond that, its not much use and can cause a real funny feeling steering. Terry

**Howard M.** · April 18, 2007, 10:31 PM

Re: Alignment woes, again...

Tim:
Have you checked the control valve for equal right/left turn bias. If not neutral, the car will steer more easily in the direction of the bias and harder in the opposite direction. This condition existed on my 67 L79 before I discovered and corrected the problem. Now it's one-handed through gradual or tight turns. The car was aligned to factory specs.

**Verle R.** · April 19, 2007, 07:10 AM

Re: Alignment woes, again...

Tim,

Please describe your wheel and tire combination. What size/width wheels, what size tires?

Thank you,

Verle

**Timothy B.** · April 19, 2007, 08:54 AM

Re: Alignment woes, again...

Thanks for the great responses! I will try and provide some answers to the questions:

**I feel I get good feedback through the wheel, as my steering is nice and tight. All parts have been rebuilt or replaced, including the steering box. Play has been adjusted and I have made sure I am on the high spot of the gears in the straight ahead position.

**My ride height is in spec, but the front is right at the low end of that spec. A newer 9 leaf spring in the rear and original springs in the front leaves the car with a very slight (and not all that noticeable) slight rack to the front.

**I am looking for the last printout of my alignment, but from my notes and earlier posts I am fairly certain that it is as follows: 0.5 deg neg camber rear with 1/32" per side toe in. In the front, ~1.75 neg caster and 0.5 deg neg camber, with about 1/16" total toein. I went to the shop twice and worked with the tech (who is knowledgeable about Vettes) to get these settings. As I mentioned, we had trouble getting as much caster as I wanted, probably due to being at the low end on ride height in the front.

**I am running about 28 psi tire pressure.

**When I say the car bounces around in turns I am referring to that fact that a Vette has a tighter suspension that a typical passenger car so bumps in the road are felt more in the seat and in the steering wheel. My shocks are only about 1 year old Bilstein HD, and they ride nice. Bilstein makes two shocks for these cars, and the HD versions aren't as stiff as the other option.

**Power steering balance valve is centered, and the car tracks straight now and has equal turning force left to right.

**Connecting rods are in the forward holes as they should be.

**Wheels are standard steel rims for 67, and the tires are Pirelli P4000s as recommended by Duke, about 2 years old now. 215/70ZR-15.

**Verle R.** · April 19, 2007, 09:16 AM

Re: Alignment woes, again...

Tim,

Correct me if I'm wrong, but I think your wheels are 5 1/2" wide. The recommended size is 205 75 15.

A 215 70 15 is a wider tire that may give a "mushy" feel on a 5 1/2" rim. I suspect the recommended wheel for that tire would be about 7" wide. The symptoms you describe sound like it could contribute to your problem. I have seen this before and the cure was wider wheels. 68 Corvette wheels are 7", will fit and should help.

Trade tires/wheels with another car that does not have your symptoms as a test.

Verle

**Duke W.** · April 19, 2007, 09:47 AM

Re: Alignment woes, again...

All '67 wheels are six inches wide and the minimum wheel width recommendation for the 215/70R-15 is 5.5". I don't think the wheels and tires are an issue. Many owners have installed these tires on OE wheels and all are very pleased with the results.

Caster is mentioned to be negative 1.75 degrees. It should be positive. I don't think you could achieve this amount of negative caster as the nominal setting is about 1.5 to 2.0 positive.

Mechanically, everthing appears to be in order, but have all the control arm bushings and anti-roll bar bushings been checked for deterioration and excess compliance.

In reviewing your original post your primary complaint is that it is difficult to hold the car in a steady mild curve. It may be a characteristic of the system that you will have to get used to. It's been awhile since I drove a C2 with power steering, but I recall that I did not like it at all - too senstive with not enough feedback.

One experiment you could try is remove the belt from the power steering pump, which will essentially make it a manual steering car and see if it exhibits the same behavior.

Duke

**Gerard F.** · April 19, 2007, 10:18 AM

Re: Alignment woes, again...

Tim,

I saw Dukes post and used his specs on the caster. I'm running 2.75 positive caster (about maxed out), 205/75R15 tires, with new front springs (grand touring), regular gas shocks, and a new 9 leaf rear spring on my 67 S/B.

I think my car tracks real well with the power steering. At least I am used to it, it did take a while.

Jerry Fuccillo
#42179

**Timothy B.** · April 19, 2007, 10:56 AM

Re: Alignment woes, again...

Yep Duke, you are right. My caster is positive not negative. Mine maxed out at about 1.75 on one side and could get maybe 2.25 on the other. I knew it was important to have them even which is why they were left at 1.75 positive.

My bushings are only a few years old (they are poly in the control arms by the way).

Your comment about removing the belt is intriguing. I think I might try that. You bring up a good point about the sensitivity of the steering however. Since I am in the "fast" forward holes of the steering knuckle, it might be that this feel is "normal"? I think what I had hoped to get from this thread is a feel for how "normal" my symptoms really are....

Alignment woes, again...

Alignment woes, again...

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