Steering on 71 - Nova Tech
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  #1  
Old Aug 22nd, 11, 07:34 AM
jp71ss jp71ss is offline
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Default Steering on 71

Ok, I have a odd problem on my 71. When I hit a bump or a dip in the road that make the front compress down the car darts to the left. The steering wheel doesn't move. I have replaced all control arm bushing, ball joints, bearings, springs and spindles with lowering spindles (it did this before all this too). I had the front end lined and the guy told me that all the tie rods ends and center link were good and tight. I have gotten under there myself and can't find anything loose. I also replaced the power steering pump and lines because it was blowing fluid out somewhere (seal looked good). You guys think maybe it is the steering box or is there something else I am overlooking?
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  #2  
Old Aug 22nd, 11, 08:05 AM
Big Dave Big Dave is online now
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Default Re: Steering on 71

Have you lowered the car? If so how? Did you install a rack and pinion aftermarket steering kit?

You are experiencing bump steer. It is generally caused by the tie rod ends not sitting on the same plane as the the lower ball joint and steering arm end link. Because they are not on the same plane the the arc that the individual parts move through is of different lengths. This causes the wheel to turn as it is moved up and down.

This is what happens just about every time you install a rack and pinion steering off of a Ford Pinto (Mustang II) onto a Nova which is what most aftermarket parts are made to resemble. The Pinto rack is too short and is mounted far too high (attached to the front cross member) on a Nova to work as it did work when on the Ford where it was designed to fit.

Your car experiences bump steer even at normal ride height, and is one of the reasons the front sub frame was changed in only three years to correct this problem with handling on the Camaro (Ackerman angle and camber gain where two other reasons). It was retained on the Nova because the Fed Government's IRS tax code required tooling costs to amortized over seven years, so the Nova was stuck with the old design. This was because it was considered to be an economy car, not a hot rod like the Camaro was sold as.

The Camaro was "rushed" into production to compete with the 1965 Mustang and went to market before the normal testing could be completed (you can blame car mags for this part of the problem as GM was trying to keep the car under wraps before it's introduction). The factory discovered the problem right off the bat in road racing (TransAm) and wanted desperately not to be beaten by American Motors which was breathing down it's neck thanks to Roger Penske's efforts. The Camaro was sold on image not it's actual performance; as the only racing it dominated was in drag racing which has a very narrow appeal (if you doubt this look at when it is broadcast on ESPN and note that golf and tennis or even little league baseball is more important in terms of demographics).

Big Dave
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  #3  
Old Aug 22nd, 11, 08:49 AM
brian oneil brian oneil is offline
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Default Re: Steering on 71

Check your shocks to ensure you dont have a blown one.
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  #4  
Old Aug 22nd, 11, 10:10 AM
jp71ss jp71ss is offline
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Default Re: Steering on 71

I lowered it with 2" lowering spindles so I would think the angles would remain stock. The shocks are new so I wouldn't think they were it plus there is nothing leaking anywhere. I replaced springs with new stock height springs and the only thing that moves is the car darts left but the steering wheel doesn't change positions. It does it when I go through a dip or in a parking lot that has a bump to go in. It doesn't feel like bump steer because it doesn't bottom out against anything and it is always darting to the left. I am concerned it is the steering box but I am not certain of the steps to check it. At first I thought it was a tire rubbing when I was turning to the right and hit a dip but it done it going straight the other day and there was no tire rub so I am getting a little concerned.
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Old Aug 22nd, 11, 10:39 AM
Big Dave Big Dave is online now
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Default Re: Steering on 71

Car doesn't have to hit the bump stop to experience bump steer. If you were looking straight down as you moved your suspension up and down (with the fender and the spring removed) you would see the tire steer as the suspension goes through it's travel.

The fix is to use a different upper control arm and a taller steering knuckle (or use the Guldstrand modification of your upper A-arm mounting point). If you go to the Team Camaro board and read the tech articles (especially those written by David Pozzi) you will understand what meeds to be done to convert your Nova into a canyon carver and respond in a predictable way.

Here is the information I couldn't find earlier (Sorry to take so long to get back with this but every time I start read anything technical I tend to get distracted in reading everything written).

http://www.pozziracing.com/first_gen_suspension.htm

Big Dave

Last edited by Big Dave; Aug 22nd, 11 at 09:50 PM. Reason: Update with Link to Pozzi Racing
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Old Aug 22nd, 11, 10:50 AM
jp71ss jp71ss is offline
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Default Re: Steering on 71

With bump steer would you feel it in the steering wheel with movement or anything?
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  #7  
Old Aug 22nd, 11, 12:37 PM
Philip Philip is offline
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Default Re: Steering on 71

Quote:
Originally Posted by jp71ss View Post
With bump steer would you feel it in the steering wheel with movement or anything?
Not always, it moves the wheels.

In the photos below the tie rod is parallel to the lower control arm and the pivot points at the frame and ball joint are in the same place so they can move in the same arc. If the angle of the arm and tie rod are different or the pivot points off they will move in different arcs and the movement of the arm can cause the wheel to be pulled out of straight by the tie rod. Are the steering arms correct for the car? I have seen some people use Chevelle arms turned backwards and it can cause the problem.



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  #8  
Old Aug 22nd, 11, 01:37 PM
brian oneil brian oneil is offline
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Default Re: Steering on 71

If this issues was happening prior to you making the suspension changes, and it is still occuring then I would be looking at what you havent changed. Steering box, Steering column, rag joint, pitman arm. Remember the pitman arm has a movable joint and they do go bad. I have chased wandering issues to the pitman arm being bad. Just something to check.
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  #9  
Old Aug 22nd, 11, 05:54 PM
Big Dave Big Dave is online now
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Default Re: Steering on 71

I am working off the assumption that everything in the front end has been replaced with new parts (except the gear box) as per his earlier remarks. He mentioned using a dropped spindle which is generally the correct way of lowering a car such that the changes do not adversely affect your steering geometry (you would have with a lowered car what you had before). In this case what he had before is a known problem.

When these cars where new the average driver thought they where absolutely great because compared to an X-frame 1958-'64 Chevrolet these cars are practically race cars. The Camaro/Nova really aren't that great, but the old X-frame Impala that was designed to respond to road input as if you where sitting a in vat of marshmallows, was that bad. Aside from the know bad steering geometry the steering gear box even when brand new (or freshly rebuilt) is sloppy compared to a late model gear box that offers feed back from the road.

In the sixties Chevy was advertising a Jet Smooth Ride. Jets where new; global warming hadn't been observed yet and the air at thirty thousand feet was calm and smooth. Chevy wanted your driving experience to be as exacting as virtual reality is today with you sitting in your Lazy-Boy over-stuffed leather recliner and watching the world move about you without a bump or wiggle to disturb your viewing pleasure.

To this end all road feed back was absorbed in sponge rubber (quite literally). Engine vibration was absorbed in sponge rubber. Road feel was removed from the steering by a rubber donut and a pencil thin rod to turn the front wheels through the application of a fourteen horsepower hydraulic pump (your sainted grand mother could turn the wheel of a parked car with just her lace gloved left hand pinky finger). The rear suspension is mounted in rubber, the bump stops are rubber. The rear leaf springs have a rubber pad on top, and below the leaf spring (with rubber in between the leaves if multi-leaf). The shocks are mounted in rubber. The seats are foam rubber. I get the impression that GM didn't trust us to drive out of our drive way as we might get hurt by bumping into something (so in 1973 and all models since we have big rubber baby buggy bumpers to pad any bumps we might experience).

If anyone has seen under a race dedicated car they will note a tremendous lack of rubber. Rubber is squishy and will not transmit forces. On a race car everything is mounted in metal: motor, transmission, suspension, seats. If you hit a bump you feel it. If your car is under steering you know it. If you have camber gain the wheel is ripped out of your hand (same for bump steer). Properly set up you have to drive a race car. It is twitchy; responsive to any input either from the road or the driver. It is tiring to have to drive that way. Twelve hours behind the wheel is considered an athletic feat (Though I don't think that race car drivers should feel ready to take on an NFL player just yet).

In the early eighties GM finally got a clue. It came in the form of the letter "M" to quote Sesame street thanks to three other letters BMW. GM never felt compelled to compete with Porsche or Ferrari but when BMW started eating into sales GM noticed European cars for the first time. They actually asked drivers what they wanted in a car instead of listening to business school graduates with marketing degrees. By 1985 power started to climb and you could begin to feel the road. Cars shrank in size and more importantly in weight with aluminum body panels (body men hated these). Tires grew in size and the suspension became stiffer with multiple valved shocks (electrically controlled on high end cars). All of this new technology can be bolted onto your car. Just look at what Philip did to his.

Big Dave
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Old Aug 22nd, 11, 10:38 PM
jp71ss jp71ss is offline
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Default Re: Steering on 71

I listed what was new in the first post and I forgot to mention the shocks and front springs were new. Tie rod ends and pitman arm was not because the alignment guy said it was good. Steering box is not new. So there are a couple things there, I have been skeptical of especially the steering box. No rack and pinion here. The tie rod end angle match the lower arms for the most part and they are original nova arms with new bushings. Rag joint is not new. I did the lowering thing when I first got it with springs only and decided to put new springs back in and get dropped spindles. I have 14 x 7 ralleys on the front with 195/70-14 tires. The drivers side will rub some when turning and I hit a bump at the same time. I always thought this was causing the jump in the steering but I noticed it on straight line driving too. So I have gotten to the point that I am always ready to move the steering wheel to the right if needed. I just dont want to take a chance of it wrecking me. What newer model, quicker ratio box can I go with? I will replace the pitman arm at the same time. Then we will see if it makes a difference. Thanks for the ideas. I hope I am on the right track.

Last edited by jp71ss; Aug 22nd, 11 at 10:39 PM. Reason: for puncuation
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  #11  
Old Aug 23rd, 11, 06:14 AM
Big Dave Big Dave is online now
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Default Re: Steering on 71

Any steering box made after 1985-'87 will bolt on and be a better box in terms of feed back. They used a different means of attaching the hoses (O-rings instead of SAE flare fittings) but you can buy either a new hose with old flare fittings on one end and O-rings on the other; or you can use adapters that fit into your steering box. You want a box with the same size Pittman arm on the box so measure yours carefully (you will need a caliper not a measuring tape).

All cars have different turning radius's and the stops are inside the box but they are adjustable. If you buy a remanufactured box for your car, the stops will set up for your chassis. You can also buy one with a variable ratio so that it handles like a manual when driving straight, but a fast acting power steering as the wheel is turned (the greater the wheel angle the faster it reacts). This is something that wasn't offered when your car was new.

Chevrolet hasn't changed the bolt pattern to mount a Saginaw steering gear box since they were first used in 1961. Even a fly weight manual Vega gear box the size of your fist will bolt up and clear a lot of header tubes that would other wise be dimpled). The difference between them is the size of the out put shaft (spline count) and the length of the Pittman arm (there are three different lengths just for your Nova that depended upon the suspension options).

The Idler arm is a major source of play in your front end because it is mounted in rubber. There are aftermarket versions of your arm (sold for the Camaro) that uses steel roller bearings for a solid mount. I have not seen a plastic version yet, thought it makes more sense than a rubber one. There are heavy duty parts (sold for roundy-round race cars) that will greatly enhance your car's handling (check out SpeedWayMotors.com for suspension parts after reading David Pozzi's and Dick Guldstrand's articles).

Here is a Popular Hot Rodding article on the subject:

http://www.popularhotrodding.com/tec...ech/index.html

Big Dave
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  #12  
Old Aug 23rd, 11, 07:29 AM
jp71ss jp71ss is offline
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Default Re: Steering on 71

Thanks guys. Interesting article Dave.
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