Brothers Trucks 1947-1959 Power Steering Installation


Brothers Trucks 1947-1959 Power Steering Installation


Safety is the single most important factor when undertaking any modification project. Any changes should be carefully studied to see how the modification will affect other components. The planned modification itself must be looked at closely to see if it and the components used are safe.

We will be using Brothers 47-59 POWER STEERING CONVERSION. Each kit is packaged with a steering arm, steering link assembly, weld-on bracket, and spacers. To complete the Stage 1 kit, you will need a Saginaw steering sector from a 1968 – 1984 Chevy/GMC pickup. You will also need a GM pitman arm that measures 6 3/4″ from a late ’70s mid-size Chevrolet car, like a Malibu. In most cases, you will have to do some reaming and fitting to get the tie rod end to fit properly. To make things a lot easier, Brothers offers an aftermarket Pitman Arm for the 1947- 59 trucks which is designed for their Stage 1 kit. Last, but not least you will need a passenger side, lower shock bracket for the 1947- 55 1st Series trucks. These parts can generally be found at your local wrecking yard. Swap Meets and Classified Ads are another good source for the sector and lower shock mount.

OVERVIEW: The weld on the triangle bracket might appear to present a problem for those without welding equipment. A bolt-on bracket can be fashioned rather easily and will provide pretty much the same support. As a test, we made a bracket from a section of 2 1/4″ angle stock a 1/4″ thick and 3″ long. We shaped the top portion of the angle stock in the contour of the triangle bracket supplied in the kit and drilled a hole for a top bolt to pass through. The bottom side of the angle stock was drilled out for mounting to the top of the frame with bolts. The lighten bubble in the photo shows the location. This is a low-tech solution and provides enough strength to support the sector. We used only a battery drill and a hacksaw to accomplish this work-around. Welding is not required to accomplish this project. 1947-1955 1st Series: When this kit is properly positioned on the frame rail, the lower front mounting boss on the sector is left hanging in space with nowhere to bolt to. This characteristic is found only on the 1947- 55 1st series trucks. While three bolts provide the necessary strength, the appearance was not the what we were looking for. GM put 4 mounting locations on their sector for a reason is our thinking. There is also some frame flexing and squishiness in the finished product when using the sector to frame mounting method alone. In order to facilitate a speedy installation and overcome the mounting difficulties, we developed a mounting plate that solves all of these issues. As seen here, the gray plate between the sector and frame really cleans up the appearance of the modification and provides the needed strength to the frame. Because of its shape and pre-drilled mounting holes, the mounting plate eliminates the need to measure out each mounting hole. There is no need for test fitting or guesswork.

1955 2nd – 1959: Compare the frame of the early trucks shown in the photo above with that of the later series truck shown right. You can see that there is no problem with the 4 bolt mounting of the sector on these trucks. The taller frame on these trucks makes the work a lot easier. These year's trucks also experience some frame flexing, even with a 4 bolt installation. This makes for a steering system that is too squishy for most people. This flexing has been found to cause some radial cracking around support holes over time. Therefore, It is recommended that piece of 3/16″ or 1/4″ plate stock be added to the inside of the frame rail to beef up the frame and better support the sector.

SECTOR MOUNTING: Assuming you have already removed the old steering sector, steering link, bumper iron, and shock mount, we can now start the installation of the Stage 1 kit.

Installing the kit without the mounting plate: 1947- 55 1st Series: Start by first measuring back from the front of the frame horn 11 1/4″ and clean the rail down to the bare metal and mark it. Next, insert a bolt through the triangle bracket. Slip the longest of the supplied 4 spacer bushings over the bolt and thread it into the sector. Now, insert a bolt from inside the frame rail through the rearmost bumper support hole. Use a large flat washer on this bolt. Next, slip a spacer over the bolt and lift the sector into place. Holding the sector up to the frame, thread this bolt into the top-front boss on the sector. Cam the sector down until the triangle bracket meets the frame rail. The center of the triangle bracket should be centered on your mark. Plus or minus an 1/4″ is close enough. Tighten the front bolt pretty snug.

Center punch the remaining hole location. Tack weld the new bracket into place on the frame. Take out all the bolts and remove the sector. Drill out the remaining frame hole and finish welding in the triangle bracket. Clean and paint the frame area where you welded and prep (paint/clean) the sector for final mounting. Install the sector using Grade 8 bolts with flat and lock washers. Space the sector off the frame with the 3 remaining spacers so the sector clears the frame.

1955 2nd – 1959: Once the stock mount is off the frame is ready for the layout of the new hole locations. Notice the brake line coming out of the side of the frame. From this point, place the end of your measuring tape on the front side of the hose connection and measure forward 12 1/2″, and scribe a vertical line down across the frame rail. Next, measure down 1″ from the top of the frame at the vertical mark you just made. Mark and center punch the location. Drill a 3/8″ mounting hole at the area you just marked. See photo. Now, attach the triangle bracket supplied in the kit to the sector with the longest spacer in between the sector and the new bracket. Bolt the sector to the frame using the new hole you just drilled. Make sure to place a spacer between the frame and sector. Allow the sector to rest on the new bracket atop the frame rail. Snug up the bolt. Mark the 2 remaining bolt hole locations and remove the sector. Center punch and drill the holes you just marked. Re-install the sector, again making sure the spacers are all in place. Tack weld the bracket in place on the frame. Make sure you have cleaned the area where you are welding down to the bare metal. Remove the sector and finish welding in the new triangle bracket. Re-install the sector with Grade 8 bolts with flat and lock washers on the inside frame rail.

STEERING ARM & LINK: Remove the top two bolts that attach the backing plate to the spindle. Place the new steering arm to the back of the spindle and align the holes in the arm with the two holes on the top of the spindle. Using new grade eight bolts, secure the steering arm to the spindle back. As a finishing touch, cut the old steering arm off and grind the cut clean as shown in the lightened area of the photo. Center the front wheels. Center the sector’s pitman arm shaft and install the pitman arm at 90 degrees to the frame. Attach the steering link to both the pitman and steering arms, and adjust the length as necessary. Secure the ends with the supplied nuts and cotter pins.

TYING IT UP: After the sector has been securely mounted you are ready to tie in the steering. In the photo below, we used a stock GM linkage from a donor car. We choose to retain the rag joint at the sector to help isolate the chassis from the steering column. This makes for a smoother feel to the wheel. In the photo above, notice the completed project on the 1955 2nd – 1959 trucks. Borgeson joints and steering shaft are used to tie in the steering here. One side of the sector joint is splined and the other side is a Double D configuration. A Double D shaft is used to connect the sector to the columns Double D joint. With only the pump installation and hose routing left to complete this project, we wrap up the power steering conversion installation.


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