Steering Box Upgrade - Steering Box Difference

Steering Box Upgrade Steering Box Repair

Note how the police version pitman shaft (left) has a double-wide locator spline (arrow) compared with the standard blind spline for all the other applications. This wider blind spline allows a standard pitman arm to assemble to the shaft on two possible spline positions. Set the steering gear on-center and assemble the pitman arm on the spline that places it along the centerline of the gear.

Note how the police version pitman shaft (left) has a double-wide locator spline (arrow) c

Interchangeability
Perhaps the greatest legacy that GM has handed down to car crafters is interchangeability. For this story, that means many of the steering boxes used in various body styles as late as the '90s can be retrofitted into classic '60s cars. But there are certain land mines that have to be negotiated to create a successful steering box swap. For example, one of the most popular power steering box upgrades for an early Camaro, Chevelle, or '68 to '74 Nova is the '85 to '88 Monte Carlo SS box. There were also a few Pontiac, Olds, and Buick G-Body cars that used similar boxes. The difficulty with this swap is that demand is far greater than supply, which makes finding one of these boxes difficult. This means we have to look for alternative boxes that will do the same job. Another popular swap candidate is the third-generation ('82 to '93) Z28 Camaro or Pontiac Trans Am steering box. In the application chart, you can see the WS and XH boxes (among others) offer an excellent 12.7:1 fixed ratio. What is not so good for A-Body, early Camaro, and Nova owners is the third-gen Camaro box's limited 64- to 70-degree pitman arm sweep. Compared with a stock Chevelle/Camaro/Nova movement of 87 degrees, this means that bolting in an '89 Camaro steering box drastically reduces the early car's turning radius. We've tried a third-gen Camaro box on a '65 El Camino and discovered that while the ratio improved and the feel is much better, the lost turning radius makes the car less fun to drive, requiring three-point turns where a simple U-turn was achievable with stock steering. There is a way to change the stops in the third-gen Camaro box to remedy this situation. We'll get into steer-ing box modifications with Lee Manufacturing in a subsequent sidebar, but the key point here is to use the application chart as a guide for choosing the best box for your application.

The chart also indicates that the fullsize Chevy (and possibly Buick, Pontiac, and Oldsmobile) B-Body styles offer a better alternative as a bolt-in performance style steering box. Note that the WZ box is better than the other two listed here because it has the highest effort while retaining the 12.7:1 ratio and matching 87-degree pitman arm sweep. These big-car steering boxes have received very little attention in the performance press yet offer most of the same characteristics as the highly prized Monte SS box. Tom Lee of Lee Manufacturing told us that the fullsize Impala police car steering boxes look like an ideal swap with high-effort numbers. However, the machined splines on the police car gear output shaft are different from all other Saginaw power gear shafts. Instead of machining out a single spline in each quadrant of the output shaft, the police car shaft has two adjacent splines machined away in each quadrant. The splines in the special police car pitman arms have double blocked teeth to match. Since the Chevelle pitman arm has only a single blocked tooth in each of its quadrants, you will be able to assemble that pitman arm at two possible spline positions on the police car gear. To install a Chevelle pitman arm on a police car gear, first set the steering gear exactly on center (flat on the input shaft pointing straight up.) Then install the pitman arm on the output shaft spline that places the arm exactly on the centerline of the gear.

Here, both inserts are installed in the box. This creates an inverted flare sealing surface for the original power steering fittings, which means you can reuse your original hoses.
Here, both inserts are installed in the box. This creates an inverted flare sealing surfac
According to Lee, you can use braided steel hose for the high-pressure side of the system if you want, but he prefers the blue high-pressure AN-style hose. Steel fittings are required because of their strength and durability. Here are Earl's high-pressure fabric hose and specific steel fittings. Do not use rubber fuel line as return hose, since it's not designed to handle high temperatures.
According to Lee, you can use braided steel hose for the high-pressure side of the system