The two key ways we interface with our Camaros is through the gas pedal and the steering wheel. In essence, a lot of thought and effort are put into the throttle side of the equation. After all, going fast is fun, but if no love is given to the steering side, the results could be a fast car with a sloppy feel. It’s a situation that can also be dangerous as you’re zipping down the highway. Imagine a new Z06 ’Vette with cruddy steering; what fun would that be?
One popular option is to replace the recirculating-ball steering box with a rack-and-pinion system, but this can lead to a lot of work and a much lighter wallet. Switching to a rack and pinion on a stock subframe can also cause fitment issues and undesired changes to the car’s suspension geometry if it isn’t done just right. Fortunately, companies like AGR offer replacement gearboxes that can give your vintage Camaro the feel of a new car. Best of all, the swap is easy and there’s no need to sell family members to medical science to afford it.
This time-tested steering system is very rugged and preferred in racing organizations like NASCAR. The install isn’t rocket science and your car will retain its factory look.
Recirculating Ball Steering Box
From about 1950 until sometime in the 1980s, the recirculating ball system was the standard in steering technology. In fact, it’s still used in some heavy-duty truck applications. Gearboxes are set up with ratios that affect the number of times necessary to turn the steering wheel to get the front wheels to pivot.
A wide-ratio box may require up to 4.5 revolutions of the steering wheel to go from lock to lock, whereas a close ratio box of 12.7:1 only takes about three revolutions of the steering wheel to go from lock to lock. So, what difference does 1.5 revolutions make? Answer: a lot! You may not notice it that much driving down to the grocery store, but if you ever find yourself on a long and twisty road, the wide-ratio box will make you work much harder than the close-ratio box. More work tires you sooner and affects your driving performance, in turn taking a lot of fun out of the experience. Whereas the close-ratio box will make your car more responsive since it requires less driver input to change course.
In addition to the steering ratio, gearboxes can be adjusted for the amount of effort, or resistance you feel while turning the steering wheel. In a car set up with low resistance, you’ll have very little feedback, and your car will have the feeling like it is floating around on the road. What’s needed is a happy medium between low effort (when you are moving slow or sitting still) and a higher effort setup that would be good at speed. After all, you don’t want to sneeze at 70 mph and end up in another lane.
There are several disadvantages to traditional gearboxes: the box consists of many moving parts and there‘s quite a bit of friction with many wear points. This is one reason why the steering feels so sloppy on an old car. The internals of the box are just worn out. Compared to a rack and pinion system, a traditional steering box is quite complicated inside, and the system has more wear points compared to a rack and pinion. But despite these drawbacks, it’s a very good system that, with the right internal parts, can perform as good as if not better than a rack-and-pinion system.
This is a great time to replace your coupler (rag joint) if it’s worn out, which it most likely is. But, if it’s still in great shape, just reuse it, since the splines are the same as the new box.
How does a recirculating gearbox work?
The recirculating-ball steering box contains a worm gear, which is comprised of a block of metal with a threaded hole in it. This block has gear teeth cut into the outside, which engage a gear that moves the pitman arm back and forth. The steering wheel connects to a threaded rod, similar to a bolt, which sticks into a hole in the block. When the steering wheel spins, it turns this bolt. Instead of the rod twisting further into the block the way a regular bolt would, this rod is held fixed, so as it spins, it moves the block, which moves the gear that turns the wheels.
Rather than have the bolt directly engage the threads in the block, all of the threads are filled with ball bearings that re-circulate through the gear as it turns and acts as rolling threads. The balls actually serve two purposes: first, they reduce friction and wear in the gear; and second, they reduce play in the gear. If it were not for this ball bearing design, slop would be felt whenever you changed the direction of the steering wheel. Without the bearings in the steering gear the teeth would come out of contact with each other for a moment, making the steering wheel feel loose and floaty.
How does a rack-and-pinion system work?
The modern rack-and-pinion is actually a very simple system. A gearset is enclosed in a metal tube with each end of the rack protruding from the tube. The gearset accomplishes two things: first, it converts the rotational motion of the steering wheel into the linear motion needed to turn the front wheels, and secondly, the gearset provides gear reduction which lessens the effort needed to turn the wheels. A rod, called a tie rod, connects to each end of the rack.
The pinion gear is attached to the steering shaft. When you turn the steering wheel, the pinion gear spins, moving the rack. The tie rod at each end of the rack connects to the steering arm on the spindle. On a power system, part of the rack contains a cylinder with a piston in the middle, which is connected to the rack. There are two fluid ports on the rack, one on either side of the piston. Supplying higher-pressure fluid to one side of the piston forces the piston to move, which in turn moves the rack providing the power assist.