I took my 1967 Chevelle to get the alignment done on Saturday with a 1/2 degree negative camber, 5 degrees of positive camber and 1/16 inch toe-in. I don’t really understand those settings but I’ve been told they work.

I have replaced many suspension pieces on my ’67 Chevelle and the entire steering linkage. I’m new to this car and this is my first “classic” car. Anyway, the power steering has always felt very light and when the car is on a straight line it seems to be insensitive to small movements of the steering wheel. With the UMI cornering kit and brand new 18 inch wheels with 245/30R18 tires in the front, I expected this car to be way more responsive to the steering wheel. I have no idea what steering box I have but I’m pretty sure it is the stock one. Is that the problem? Any suggestions?

B.T.

It sounds like you have selected a nice lineup of good suspension parts for your Chevelle. What these additions now point out is what sounds like the worn, original steering box.

The stock early Chevelles uses a relatively “slow” steering ratio that is often counted in the number of turns from full lock left to right. These stock boxes often are between 3-3/4 and 4 turns lock-to-lock.

This ratio offers very easy steering but as you’ve noticed, it is very slow to respond to input.

Back in the 1960s this was what GM thought everybody wanted—what hot rodders often describe as “one-finger” power steering, because it only takes your index finger to steer the car. Add to this is a car with probably over 100,000 miles on the original box, so it’s loose at the center point (since that’s where 98 percent of all driving is performed).

Testing Different Steering Boxes in a Classic Chevelle

There are several solutions for early Chevelle owners to remedy this issue. The easiest thing is to point you to a custom built steering box from a company like Lee Power Steering in California or from Detroit Speed.

I helped my friend Cam Benty with his story on quicker steering boxes using my 1967 Chevelle to do the testing. We first tested the car with a steering box from a 1988 Monte Carlo, which is much quicker with a better feel than the original Chevelle box. We then changed to a Lee Power Steering 12:1 box.

Steering box for an old car
Externally, the upgraded steering boxes mostly all look the same. This is a Detroit Speed upgraded box available through Summit Racing. The response through the steering wheel the first time you turn the wheel will reward you with a brand new feel for the road! (Image/Summit Racing)

The 1988 Monte Carlo box is very much quicker than the original, but the Lee box instantly felt much quicker than the Monte Carlo box but the change in ratio was negligible which was strange until owner Alan Padelford explained that much of the “feel” of steering is related not to the actual ratio, but to the amount of effort required to initially turn the steering wheel.

This feel is connected to two basic factors.

The first is the size of what is called the input torsion bar. This is a small bar located in the input shaft of the steering box that deflects when force is applied to the steering wheel. A larger torsion bar will require more driver effort.

In our test on the Lee Power Steering boxes, the variable ratio Lee box demanded a much higher input feel with the 35 to 40 inch/pound settings and it definitely had an outstanding performance feel that seemed much more responsive even though the ratio was not that much different.

The original 1960s boxes all used very small torsion bars to produce that minimal effort. Steering box improvements in the 1980s increased the size of torsion bar which increased the effort which improved the “feel” for the driver.

However, Padelford has told us that another major variable that affects steering input feel are the many clearances inside the box. He told us that these clearances are often much less than 0.001 inch. This means that as the steering box wears, this increases these clearances, reducing the feel and overall performance of the steering box. Padelford prefers to refer to this effort in inch/pound ratings as opposed to just looking at the torsion bar diameter.

Lee Power Steering says stock early boxes used a 25 inch/pound rating for input while they recommend a box with a slightly higher rating of 35 to 40 inch/pound and for off-road or racing they will increase this input to as much as 60 inch/pound.

A common suggestion from Chevelle enthusiasts is to retrofit a 1988 Monte Carlos SS steering box for early Chevelles. These rebuilt boxes can be found in many different forms and from many different retailers. We’ve listed the rebuilt version of this box from Cardone in the Parts List.

Consider the Power Steering Pump

Another aspect to all of this is related to the flow and pressure output from the power steering pump. Space considerations don’t allow us to get into all the details as that entails almost a college course in power steering system tech. Often times, power steering systems at high speeds will feel “twitchy.”

Many enthusiasts think that merely lowering the pressure will improve this situation.

According to our friends at Turn One, who specialize in high performance power steering pumps and steering boxes, this situation is more often related to the rate of flow from the pump and not necessarily pressure. While both are important, Turn One sells multiple flow fittings for both the early Saginaw as well as the later model Type II power steering pumps that can alter the flow capacity. This is a subject best left to contacting Turn One as each application is different and requires specialized experience. They can help you with fine-tuning your system with custom flow restrictors as well as improving the system’s overall performance.

Summit Racing offers all of these parts as well as upgraded Turn One pumps and custom pulleys, so they will have you covered.

***

As you can see, there are lots of options here with power steering box ratios, pump pressures and flow, and even down to the power steering fluid. We would recommend a quality synthetic power steering fluid since aggressive driving like track days can elevate the power steering fluid right past the 250 degree F peak temperature of conventional fluid where it begins to oxidize and fail. We’ve seen instances where power steering pumps have failed because of these elevate temperatures during track days, so choosing a quality synthetic will go a long way toward preventing these issues.

Chevelle Steering Upgrade Parts List

  • Detroit Speed steering box for 1964-67 Chevelle – DSR-090215DS
  • Cardone retrofit quick ratio steering box – AAZ-276550
Keywords
Ask Away, Detroit Speed, steering box, Turn One
Share this Article
Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.