Rack and Pinion Steering
Rack and Pinion Steering
Rack and Pinion Steering
Rack and Pinion Steering
Rack and Pinion Steering
Rack and Pinion Steering

Rack and pinion steering systems are available in many configurations for universal and direct-fit applications. The last time we checked, Summit Racing has almost 1,100 different rack setups available.

A rack is a very simple device. The pinion gear meshes with a straight shaft (the rack) that has gear teeth machined into one side and is connected directly to the front wheels. When you turn the steering wheel, the pinion gear turns and moves the rack in the direction of the turn and moves the wheels. All of the gear is located in a compact housing, usually made from aluminum. This Flaming River Ford Pinto-style rack from Summit Racing tips the scales at a mere 12 pounds.

Rubber bellows cover the inner tie rod assemblies, keeping road and track grime out of the inner workings of the rack. The metal clip shown is the most common way to fasten the bellows to the rack.

Some rack and pinion systems have a slightly longer input shaft to make it easier to hook them up to the steering column. You’ll find a variety of different input shaft spline counts. Our Pinto rack has a 26-spline setup—the standard for most Flaming River racks.

Yet another consideration is the mounting arrangement. Our Pinto rack uses two cast bosses and requires this additional billet clamp in a custom drag race or street/strip application. Other racks have different layouts.

When installing a rack in a custom application, you’ll almost always have to deal with bump steer. Typically, bump steer will occur when the car has a mismatch of steering and suspension components (wrong angles and/or lengths in the steering linkage in relation to the suspension components). Flaming River makes a kit to resolve the problem. It positions the steering rack tie rod-end in line with the lower control arm. Not only does it cure bump steer, it provides an easy way to set toe.

When it comes to steering systems, rack and pinion systems are light years ahead of the recirculating ball steering boxes found in our favorite 1960s and ‘70s muscle cars and trucks. A recirculating ball steering box system is heavy, bulky, and complex, especially when you factor in the steering linkage.

In sharp contrast is the rack and pinion system.

In a rack and pinion steering system, the steering wheel and steering shaft are connected to a pinion gear. The pinion gear meshes with a straight shaft (the rack) that has gear teeth machined into one side and is connected directly to the front wheels. When you turn the steering wheel, the pinion gear turns, which moves the rack in the direction of the turn and moves the wheels.

The steering gear is mounted inside a compact rack assembly. The steering linkage consists of two inner tie rod ends attached to the steering rack, protected by a pair of rubber boots (bellows). They are linked to outer tie rod ends, which are attached to the suspension arms on the steering knuckles.

The real beauty of a rack and pinion system is that it eliminates much of the steering linkage found in a recirculating ball steering system. For example, you can mount a rack in a “front steer” layout, which places the linkage ahead of the front axle centerline. This frees up considerable space under the engine for things like the oil pan and headers.

The Ford Pinto rack and pinion system is a drag racing favorite. Summit Racing offers Pinto racks from both Wilwood and Flaming River. These racks are quick (3.75 turns lock-to-lock), have aluminum housings, and tip the scales at a mere 12 pounds. Rack travel is 5.25 inches; overall length of the assembly is compact 45.5 inches. Summit Racing also offers Flaming River Pinto racks that are five inches narrower than stock. They’re perfect for Willys, Anglia and other narrow chassis applications. This is particularly appealing if you’re building a nostalgia-style race car.

In some applications, the rear steer (linkage behind the front axle centerline), a Dodge Omni-style rack might work better. It’s particularly useful in cars where something like a radiator or front suspension crossmember might interfere with the steering shaft. This rear-steer design mounts behind the crossmember but still provides adequate oil pan clearance—for example, a small block Ford engine with a front sump pan. The Omni rack is designed to accommodate Mustang II-type spindles and outer tie rod ends.

Summit Racing also offers Flaming River Mustang II and Fox body Mustang racks as replacements for manual steering, conversions from power to manual steering, etc. There is even an MGB/Cobra rack for Cobra kit cars that weighs less than 10 pounds.

It’s easy to see why rack and pinion steering has become the system of choice for both major automobile manufacturers and racers, alike. They’re simple, reliable, and light.

 

 

Author: Wayne Scraba

Wayne Scraba is a diehard car guy and regular contributor to OnAllCylinders. He’s owned his own speed shop, built race cars, street rods, and custom motorcycles, and restored muscle cars. He’s authored five how-to books and written over 4,500 tech articles that have appeared in sixty different high performance automotive, motorcycle and aviation magazines worldwide.