In the early days of the motorized age, everything under the sun was considered a possible means to steer a vehicle. The first ones (horseless carriages) steered with a tiller, a simple device not unlike a folding Radio Flyer wagon handle. With the introduction of numerous brand names by 1903, various different types of steering mechanisms were utilized on American vehicles. To name a few, the '03 Oldsmobile and '03 Rambler steered with tillers connected to what could best be described as variations of Rudolph Ackermann's steering arrangement patented in London, England, in 1817. The most notable system was the adjustable rack-and-pinion steering installed on the new Cadillac introduced in October 1902 at the New York Auto Show.

By 1912, the second American automobile with a French name destined to become a part of the General Motors lineup debuted. The first Chevrolet appeared with a steering apparatus known as the worm and gear type. The characteristic differences inherent between the two types of steering introduced over 100 years ago on Chevrolets and Cadillacs still exist in today's modern rack-and-pinion and recirculating-ball steering arrangements.

As the weight of Cadillac cars (not to be confused with Cadillac trucks of that era) grew with each year, the advantages offered by rack-and-pinion steering diminished until it was necessary to abandon it in favor of a variation of a worm and screw setup. By the early '50s the worm and gear arrangement had evolved into recirculating-ball. Essentially, recirculating-ball operates in the same fashion as worm and gear, with the exception of the ball bearings functioning in place of the threads on the steering worm. The advantages of recirculating-ball over worm and gear are twofold: First, the ball bearings reduce friction and wear, which translates into a lighter feel and longer steering component life. Second, they reduce play in the gears. Without the ball bearings filling in the gap between the steering gear's meshing teeth, the additional clearance translates into steering slop. For the benefit of Custom Classic Trucks' valued readers, we'll discuss the pluses and minuses of recirculating-ball versus rack-and-pinion steering with and without power assist.

Starting with vehicles set up to drag race, recirculating-ball manual steering as equipped from the factory (provided it is in good condition) will work just fine. There's a weight advantage of 20-30 pounds sans the power steering pump with its related gear, and no horsepower lost driving the pump. A dragster, typically with skinny meats on the front and little demand to handle g-induced understeer, isn't likely to overburden its ability to steer. But add wide rubber to the front end and throw the same dragster into the curves and things can get a little intense.

Turning the truck into something that handles requires a faster steering ratio and being able to steer the front wheels with reasonable effort. For manual steering, faster means higher gears, and just like a bicycle this means it requires more muscle to make things move. The addition of power assist with a faster steering ratio on a recirculating-ball steering arrangement is a step in the right direction, but it doesn't solve all the problems. Recirculating-ball's upper hand over rack-and-pinion is mechanical advantage-the ability to leverage a heavier steering load. Rack-and pinion steering provides less mechanical advantage than recirculating-ball, but it offers less backlash (steering slop), providing more feedback at the steering wheel. To compensate for rack-and-pinion's lower mechanical advantage and allow installation on more demanding applications, power assist has been incorporated into rack-and-pinion systems in recent years.

But this doesn't necessarily mean rack-and-pinion is the new crowned king of steering. On the opposite side of town where the other school of thought labors, technology hasn't stood still, either. Interestingly enough, within the last 10 years there have been advancements in recirculating-ball steering arrangements as well. To address the issue of steering slop, rack-and-pinion valving was added to the new generation of recirculating-ball setups.

If you're saying to yourself, "You didn't tell us which system is correct for my truck," you are right. The bottom line is that the decision can only be determined by the truck owner himself. Thanks to the automotive aftermarket, vintage truck enthusiasts are no longer stuck with steering designed for trucks originally equipped with a fraction of the horsepower of today's customized classic trucks.

In order to decide whether to convert to an aftermarket rack-and-pinion setup or upgrade to the current recirculating-ball, there are several considerations to weigh. First, narrow down how the truck will be used, and decide which type fits the bill best. Second, conduct a feasibility study and learn how much work is involved to convert a particular application. Third, and almost always the detail that can make or break the deal, figure out whether your dreams and your budget agree.

SOURCE
Borgeson Universal Co. Unisteer
www.unisteer.com
Flat Out Engineering
Rancho Cucamonga
CA
Classic Performance Products
175 East Freedom Avenue
Anaheim
CA  92801
800-522-5004
www.classicperform.com
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