Photos by the author and courtesy of Speed Direct and Legendary Motorcar Company.
One of the most important components in your classic ’Vette, or any car for that matter, is the steering. How it works and behaves affects just about every other dynamic aspect of the car, including handling, stopping, and acceleration. It’s also going to wear out over the course of time. Yet it’s amazing how often it gets overlooked, as many enthusiasts tend to focus on upgrades for the engine, suspension, brakes, etc. But no matter how fast it goes or how well it stops, a car isn’t much good if it can’t steer properly.
On 1963-82 Corvettes, the steering system is one aspect of these cars that has long been recognized by enthusiasts as a weak link. The primary issue stems from the basic design. Like most cars at the time, ’Vettes of this era employ a re-circulating ball steering system, actually derived from that used on the solid axle cars, but geared shorter (19.6:1, compared to a very slow 21.0:1 found on the 1962 model). To help reduce road shock and the risk of bumpsteer, engineers fitted a hydraulic steering damper, mounted on the left side frame rail, that connected to a relay rod. Also introduced for the first time was power assistance, using a hydraulically operated ram that attached to the steering box and a control valve, plus a power steering pump mounted on an engine accessory bracket. It not only made steering easier, but quicker too, reducing the ratio to 17.1:1. During the course of this basic chassis’s production run (including the updated C3 from 1968 all the way to 1982), the basic steering system remained largely unchanged. On the C3 cars, with the adoption of radial tires in the mid 1970s, calibrations to the steering assembly were needed to optimize handling, because the new tires were wider and ran at lower pressure. Cars built from the 1975 model year onwards got power steering as standard, plus a revised control valve which used a 40-pound internal valve spring, instead of the 50-pounder found on the earlier cars. This was done to make the steering more responsive, and partly explains why the later C3s (lack of big-block engines and wider tires notwithstanding) felt more agile through the corners.
However, the C2-C3 power steering system suffers from a couple of problems. One of the most common is a loose, disconnected feel over bumpy roads, causing the front wheels to wander without a great deal of steering input. On 1963-82 Corvettes (whether they use manual or power steering), this is often contributed to a worn relay rod; because of its location by the front tires, it often gets pelted with road debris and bears the brunt of driving on rough pavement. On cars equipped with power steering, leakage is quite commonplace, as the seals in the control valve deteriorate, causing it to weep. The power steering hoses also deteriorate over time–becoming brittle, causing cracks to develop and the fluid to leak out. Even if they are in relatively good shape, they can chafe against the side of the frame and come apart. The control valve on power steering-equipped cars can also be a problem itself, as the internal spring wears out. This can actually result in very twitchy handling, whereby the car darts from left to right with minimal touch to the wheel.
BUDGET AND GOALS
Given that 1963-82 Corvettes are now very old cars, even if they have relatively low miles, chances are the steering components will still need attention, at the very least because rubber hoses and seals tend to dry out. The question is: what do you do next?
That all depends on what your objectives are with the car, and how much money you can realistically afford to spend. Given the pedigree and desirability when it comes to 1963-67 Sting Rays, the general tendency is to rebuild or restore the steering system, as close as possible to factory specs. The same also applies for ultra-desirable early C3s, like the 1968-69 L88s and L89s, plus the 1970-72 LT-1 and LS-5 454-engined cars. Post-1973 Corvettes tend to command less money and, as a result, are generally considered more appropriate for modification.
When it comes to getting the parts you need to rebuild your steering assembly, General Motors Restoration parts, and companies like Mid America Motorworks and Zip Products which specialize in Corvettes, are a good source. They can sell you all the individual components required to rebuild your existing steering box, including the seals, races, plus all the bearings for the box and worm gear assembly. For a complete rebuild kit on a C3 Corvette, you’re looking at around $80. Do bear in mind that in order to perform a successful rebuild on your steering assembly, you need to make sure that you’ve got a decent foundation. For example, if you’re planning on rebuilding the power steering system, you’ll need to make sure that your control valve casing isn’t damaged or cracked, or the ram isn’t seized. Secondly, because the power system uses a hydraulic shaft inside the pump, you need to make sure the shaft isn’t damaged. If it’s bent, then the pump is useless and you’re better off just replacing it with a new or remanufactured unit. When performing a rebuild, you’ll also need to make sure you balance the control valve properly before you remove the jacks and put the front wheels on the ground. This is important so the hydraulic ram cylinder can move up and down freely; otherwise, you’ll find the car will be difficult to steer and that it will not only affect alignment and tire wear, but require you to replace the ball studs and possibly perform another rebuild sooner than planned.
Another option is to purchase new or rebuilt steering components This saves time, but it also costs more–you’re looking at around $200 for a completely rebuilt 1968-82 steering assembly, though it is ready to bolt on. Companies like GM Restoration Parts and Zip products offer completely rebuilt pumps, new rams, steering boxes, and control valves; all you need to do is attach the hoses, bolt the system together, and attach it to the steering shaft and chassis. But remember that many replacement or remanufactured control valves are of the newer, post-1975 variety with the 40-pound internal springs. If you have a pre-1973 Corvette, especially a big-block car that still runs on bias-ply tires with the narrower wheels and higher tire pressures, the 40-pound valves can deliver too light a steering feel, making the car even more of a handful to drive, so it’s worth trying to find a unit with a 55-pound spring–there’s enough knowledge and expertise in the classic Corvette field that someone should be able to help you.
MANUAL TO POWER
A popular conversion on many 1963-82 Corvettes–especially C3s–is converting a manual steering-equipped car to power operation. It’s also not as complicated as you might think. If you are going this route, you need to make sure that you choose the right kit for your car. Running changes (like the 350 small-block V-8 replacing the 327 for 1969), plus options like air conditioning, are critical for choosing the right kit since you’ll need to add brackets for the power steering pump and use the right pulley, depending on whether the car runs air or not. Zip Products is among the companies that sell complete Power Steering conversion kits for C2s and C3s, including the hydraulic ram, control valve, brackets, power steering pump, pulley, relay rod, and Pitman arm, though you will need to source a crank pulley and drive belts. The Zip products line of kits includes applications for 1963-74 Corvettes with 327/350 high performance V-8s in A/C and non-A/C applications, as well as kit for big-block 427-engined cars (1966-69). These kits tend to cost between $800 and $1,000.
RACK AND PINION CONVERSION
In its day, the re-circulating ball steering system on the C2 and C3 Corvettes was well designed and more than adequate. But compared to more modern rack-and-pinion designs, has its limitations. It’s not only fairly maintenance intensive as we’ve discovered, but also slow and feel is a bit numb. For some drivers, this doesn’t inspire much confidence, especially during more sporting jaunts. For those that want their classic ’Vette to steer like one that’s 30 years younger, and aren’t too concerned about originality, there’s always the option of converting to rack and pinion. Although these kits are quite expensive–around $1,400–there are many benefits to using them.
One of the most popular is the SpeedDirect Steeroids Rack and Pinion system available for small-block 1963-82 cars. Besides quicker steering, the benefits of replacing your factory setup with a kit like this are reduced front-end weight and greater strength, which really helps handling–especially if you drive the car regularly or plan on attending a few track days. This was the case with the owner of this 1979 L-82-engined car. Already the recipient of larger wheels and tires, as well as a few engine upgrades, now was the time to improve the steering.
In this picture you can see the standard C3 Corvette power steering system with the rack, steering box ram, and control valve. Although good in its day, it is rather vague and prone to fluid leakage by modern standards.
On this Sting Ray chassis you can see the factory pitman arm where it connects to the tie rod and steering rack, just below the motor mount. From looking at the design of the linkage, it’s easy to see why these cars were prone to bumpsteer over time and use.
Here you can see the steering shaft on a 1967 Sting Ray. Notice the splines and design of the receptacle where it mates with the factory steering box.
In vintage racing, because original components have to be used, modifications need to be subtle. In the case of this 1968 Corvette that competes in the Sportscar Vintage Racing Association series, you can see a modified factory steering box setup. Going to a modern rack and pinion setup is not permitted under SVRA rules.
Here is our replacement Steeroids rack and pinion steering kit, courtesy of Speed Direct. The Steeroids kit features a three-piece linkage with a single universal joint that connects with the rack and pinion, a center shaft, and a double U-joint that connects with the ’Vette’s existing steering column. Because like modern steering systems, the power steering pump has hoses that connect directly to the steering rack, the Steeroids kit eliminates the need for the troublesome ram and control valve system, ensuring greater reliability and much less chance of seeping fluid. It comes as a complete bolt-in kit and includes the new rack, mounting brackets, inner and outer tie rod ends, new power steering hoses, and all the required bolts, washers, and fittings. Before you start it’s a good idea to make sure you check off all contents in the boxes so there are no missing parts.
Our first job is to remove the existing steering system from our 1979 Corvette. The first task is to remove the old hoses and drain the power steering fluid, followed by pulling the pitman arm from the steering sector shaft and then unbolting the tie rods. Then it’s time to remove the old steering rack and steering box assembly, and put them aside.
Now we can begin installing the new parts. First to go on are the brackets: Speed Direct supplies brand-new bolts to install them onto the chassis rails. A good tip is to install the passenger-side bracket first, since you might have to loosen that on the driver’s side when it comes to connecting the universal joint to the car’s original steering shaft, in order to have enough clearance.
Once the brackets are installed, you can turn your attention to the rack itself. There is a steel plate that fits over the rack to protect it (the plate should be installed with the link joint connections at the top).
Next comes the fiddly part: mating the universal joint to the steering shaft at the top and to the new rack at the bottom.
On our install we loosened the rack bracket on the driver’s side to facilitate the installation. To make things easier, you need to rotate the pinion from left to right and count the number of turns lock to lock and measure the center distance. You also need to check that the flat part of the pinion coupling is at the top when looking down from above. This will help center it and make alignment that much easier.
Once the universal joint has been loosely installed from the bottom first, carefully mate it with the steering shaft at the top. Once it does fit nice and snug, you can then tighten the bottom of the joint–and in our case, the brackets and steering rack.
Now it’s time to install the link joints and tie-rod ends. The joints need to be installed as indicated in the instructions, with Loctite to secure them. The tie rods need to be fitted with the rack centered as much as possible. The tie rods also come with spacers, which are designed to position the tie rods parallel to the road surface when the tires are touching the ground. This helps eliminate bumpsteer.
You then need to check that your steering is smooth, right through a full turn of the wheel. If there is any binding, you’ll need to adjust the universal joint down on the steering column. Speed Direct provides helpful tips in the instructions for doing this.
Our last task is to install the two power steering hoses to the rack and the Corvette’s existing power steering pump. The O-ring fittings are on the end that connects to the rack. You might have to loosen the rack brackets again, to install the hoses.
Test-fit all the bolts and fittings; once everything is correctly tightened, you can lower the car back down to terra firma. All that is left now is to refill the power steering pump with fresh fluid, bleed the rack, and head out to the alignment shop.
Corvette Steering Service Inc.
2215 Mullinax Drive
Anderson, SC 29625
Flaming River Industries
800 Poertner Drive
Berea, OH 44017
GM Restoration Parts
Legendary Motorcar Company Ltd
8228 Fifth Line
Ontario L7G 4S6
Mid America Motorworks
17082 N US Highway 45
Effingham, IL 62401
1901 S FM 129
Santo, TX 76472
8067 Fast Lane
Mechanicsville, VA 23111