Quick Turn

While equipped with factory power steering, our 1971 ½-ton Suburban had no real road feedback and was simple to turn with its one-finger power assist. Actually, it had to be easy to turn since it took over four turns to travel lock-to-lock! Turning was effortless but it was slow and sloppy, exactly what you’d expect from an almost 50-year-old truck steering system.

The Borgeson box has a turning ratio of 12.7:1 versus the stock ratio of 17:1. This ratio is determined by the number of turns that the input shaft makes compared to one turn of the output shaft (where the Pitman arm connects). To put it another way the new box now turns lock-to-lock with three turns of the wheel. One turn less may not sound like a lot on paper, but wow does it make a difference from behind the wheel!

For two-wheel-drive C10 fans, Borgeson has you covered as their new box is a bolt-in for 1967-1987 models. (They have a different model for 1963-1966 owners.) For 1977 and newer trucks the fluid lines bolt right into the 16mm and 18mm by 1.5 O-ring ports of the steering box. For older trucks, Borgeson supplies a pair of brass ferrules that allow the use of the OEM inverted flares.

If you’re upgrading a manual steering truck to power steering, you’ll need a new Pitman arm to finish the installation. Also, for 1976 and older trucks you’ll need a new half rag joint to connect the 3/4-20 spline of the new steering box to your steering column shaft. (The older boxes have a 13/16-36 spline shaft.)

The Borgeson box bolts right in place of the original and the lines are in the exact same spot (the larger port is the high pressure side and is located closer to the engine). In fact, the installation can easily be handled with hand tools, except the need of a Pitman arm pulling tool, which can be rented at most parts stores. Also, make sure you have a socket large enough to remove the Pitman arm nut or you’ll be making two trips to the store.

The quick ratio of the steering is a huge improvement, especially at slow speeds and around the neighborhood, however we’re still surprised at what a difference the new box made to the feel of our Sub on the road.

2. There is just no graceful way to drain the power steering fluid so grab a pan, some rags, remove the two lines from the box, and let it drip.

4. A Pitman arm puller was borrowed from the nearby big box auto parts store. Getting the arm loose was easy, but it was a little trickier to slide it off the steering shaft.

We ended up removing it from the draglink as well.

6. Be ready for some weight as the old unit loosens free; these things are not light!

8. Before mounting the new box you’ll want to center the steering shaft by turning it side to side then stopping in the middle. Once centered, the four flat spots on the Pitman shaft will be at the 3, 6, 9, and 12 o’clock positions. Have a bolt or two at the ready. It’s a good idea to have someone available to help hoist the new box in place while getting the mounting hardware lined up.

10. A new Pitman arm nut and lockwasher are supplied, and do not be shy about using some muscle on this nut. In fact, the spec we looked up with is 125 ft-lb.

11-12. If we had it to do all over again, we’d install the brass ferrules into the fluid ports before installing the box. They went it fine but we couldn’t get a good visual on placement before installing the two fittings.

14. With the heavy work over, it was time to bleed the system, top it off, and head out for a testdrive. The Borgeson box was as bolt-on as it gets—and the performance of the quick ratio box was instantly recognized.