Ok, my 75 has a handling issue. Mostly at highway speed on sweeping curves. It turns in well to the left... very sure footed. Turning to the right, it gets a bit twitchy and seems to 'float' a bit.

So, today I put it up on the ramps and crawled under to take a look.

Mostly it looked ok to me. I found a loose bolt on the left hand upper control arm shaft... tightened it up. The boot on the left ball joint looks bad so I probably need ball joints soon but nothing seemed out of place. So I greased the ball joints, and the all the steering points.

I then took it for a test drive. I got up to 50 and the car got REALLY squirrely! Went into a parking lot and did some circles. Turned nice to the left...to the right, it felt like the front right wheel wanted to come off the ground.

What did I do to make it worse?

 

 

where are located?

 

Hiding in my basement right now... Severe thunderstorm warning going on.

I'm in Lakeville.

 

Your problem may actually be in the rear of the car. What you need to do is to put the car up on stands (first the front wheels...then the rears) and check to see how much 'play' you have in each wheel by grabbing it on the sides of the tire and trying to shake it with a twisting motion and also grabbing at top and bottom and doing the same in that direction. You are looking/feeling for any looseness in the joints and/or movement in the linkages. You can also use a 2x4 as a pry tool in the up and down direction [under each front tire] looking for deflection in the ball joints. You may have a bad bearing or trailing arm bushing(s) in the rear, ball joint or steering link problems in the front, or a weak ragjoint coupling on the steering column/steering box input.

 

I just jacked up the car as suggested.

Grabbing each front wheel at the top and bottom, there is about 1/4" movement.... it almost 'clicks'.
Grabbing the sides and twisting results in lots of movement. This is also reflected in the play at the steering wheel. ( I was already shoppng for a steering upgrade )
With the weight off the wheels, there is a definite difference in effort to turn the steering wheel in each direction. Easier to the right and firmer to the left.
I also watched the steering cycle from under the car as my wife turned the steering wheel. It looked like it was moving smoothly with no extra movement in the idler arm or steering box.
In the rear, grabbing the wheels top and bottom, each wheel had the same 1/4" movement as the front. Side to side, there was also some movement..... maybe a little more then 1/4".

I plan on upgrading the suspension and steering (rack attack) over time, but I can't afford to do it all at once. I'm hoping I can fix the handling problem in what ever I do first so that I can at least drive the car this summer with some confidence.

So what do you guys think? Steering first or do I need to rebuild the front suspension, trailing arms????

 

If you greased the steering control valve it could cause temporary problems. It sounds like the valve is not balanced correctly.

 

I've been researching suspension upgrades for my 75.

I'd like to improve the handling without making it tooooooo stiff. I'd like to lower it an inch or so. Street use only. Plan to keep the current 225/70/15 tires for now.

Is the VBP Street and Slalom kit too stiff for street only use?

Anybody have any experience with the Van Steel Advanced Street and Slalom package? The variable rate coilovers and adjustable rear shocks sound interesting and seem like a good match for the street. Is it worth the extra cost?

 

Sounds like ball joint issues, mostly. Since no real movement in idler arm and steering box, that's two things you can check off the 'must do now' list. I didn't see anything in your thread about checking the condition of the ragjoint (flex coupling between the steering column and the steering box. That is a common area of steering problems. With only 1/4" movement in any direction in back (and, apparently, no unusual noises back there), your trailing arms and bearings would not seem to need any immediate work. (And that's a good thing!)

When your wife turned the steering wheel, did you notice if all of the steering arm/joint action worked "together" or if it looked like the separate pieces operated differently with respect to each other. If the latter was the case, you have some steering arm ball joints that are worn [or worn out]. If there are several things that you have concerns about, I would suggest that you ask around (car clubs, car shows, etc) to identify a GOOD alignment shop, take it to them, and ask them how much to do a "general steering and suspension inspection" on your car. A good, caring shop will do that for about $25-35 without expectations of doing any other work. Some will tell you that if they do any further work for you, they will remove any up-front inspection fees. But, you deal with that however you need. Changing steering arms/rods is really pretty simple work and you can easily DIY with some basic tools. If you choose to do so, ask in another thread how to measure existing stuff before you disassemble and how to reassemble using those measurements to get it aligned decently so that you can safely drive to the alignment shop afterwards.

 

I finally figured out where 90% of the slop is coming from!

The control valve.

When watching the steering system move (wife turning the steering wheel ) everything moved smoothly, but when I twisted the drivers side wheel, I could see the extra movement at the connection between the control valve and the pitman arm.

Thanks for all the information and tips!

 

Sounds to me if the control arm shaft nut was loose, maybe in the mean time you lost some shims. Then you retightened with lost shims and misaligning front end even more. Seems to me this would cause this much of a difference. Control valve will have play in a static scenario.

 

I don't think the movement I saw was normal. It looked like it is ready to completely fail. There is probably 1/2" to 3/4" movement on the shaft between the valve and the nut above the pitman arm.

The bolt that was loose was on the upper A-arm bushing, not where the a-arm connects to the upright.... but.....

Today, I was looking at the upper control arms and noticed that the driver side doesn't have any shims, and the pass. side only has 1 shim on the rear nut.

So you may be onto to something too.

 

This to concerned me on my car, start the car and do the same tests. If normal operation exsists play will dissapear.

 

I tried the same test with the engine running. Some of the play was reduced, but it still had quite a bit. I grabbed the drivers side wheel on the sides ( with the tire off the ground ) and twisted it. Most of the movement happened between the control valve and the pitman arm.

 

If the valve has some age on it replace. Hundred bucks if youvlook hard enough. Then after that check all other sources for play. Resolve all looseness and carry to alignmentshop of your choice. Still willing to bet you have lost shims. Good luck and reply if you need more suggestions. ...VIC...

 

Continuing on your missing shims idea... I crudely measured the camber using the level app on my Droid. It's rounds to full degrees so it's not totally accurate but... front wheels measured at positive 2 degrees and the rears at positive 1 degree.

Once I fix the steering I will get an alignment.

 

Thanks for all the help!

 

Remember camber adjustment affects all other values such as toe and caster also which can cause drivabiility issues.;-)

 

Just so you understand how this P/S works:

The control valve has springs on the ball joint. Those are 'cushions' to absorb movement spikes so that the steering won't be jerky. You will see movement in the ballstud relative to the control valve body when the steering system is actuated. What you are probably seeing is the end result of some binding somewhere else in the steering linkage. That binding will translate to jerky movement experienced by the control valve.

You may have truly diagnosed some internal binding in the control valve...but it is more likely that you are just seeing the translated movement of binding elsewhere. Continue to investigate until you are sure there is not binding elsewhere. Otherwise, you will spend money for a new control valve that is not needed and you will still have the problem.

 

Have that car aligned by a professional, who is familiar with old Corvettes. Then you can stop making guesses, and make informed decisions.


Scott