Project Big Bad Chevy: Steering

Nov. 17, 2008 By Mike Lyon
project big bad checyWith the addition of heavy-duty axles and larger tires for Project Big Bad Chevy, we needed to upgrade the steering system to something that would allow us to turn the large 39 inch tires during high traction, low speed maneuvers, without over loading the stock steering system. Performance Steering Components’ (PSC) hydro-assist kit and Off-Road Designs’ cross over steering kit were the solutions we were looking for.

PSC (www.pscmotorsports.com) has been a long time leader in the hydraulic steering market. They manufacture performance power steering components for off-road racing, rock crawling, street trucks, and track racing. From full hydraulic steering to hydro-assist, PSC makes something for just about every vehicle out there as well as providing stock replacement parts. The demands of turning big tires at very low speeds are high so we needed some of the best parts we could find.

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For our needs we used PSC’s hydro-assist kit for GM trucks. The kit is complete and comes with a steering gear box, high performance pump, new reservoir, steering ram, high pressure hoses, heim joints, weld on tabs, and new hardware. The steering gear box included in the kit is a reconditioned two wheel drive OEM unit. The two wheel drive steering boxes have an output shaft that allows the pitman arm to be installed pointing towards the rear of the truck which permits side to side motion rather than the front to back motion found in the four wheel drive’s steering gear. PSC fully disassembles, inspects, and rebuilds each box to ensure a fully functional steering gear box. They also add hydraulic ports to connect to the steering ram, add a custom machined sector shaft cap for extra durability and enhanced future adjustment and provide a CNC machined end cap with the PSC logo engraved into it.

Off-Road Designs (www.offroaddesign.com) is another well-known company in the off-road world. Stephen at ORD has been designing off-road parts to ensure a trouble free trip on the trails for many years. The stock GM steering system suffers from serious geometry flaws when you’re in a tight, high flex, off-road situation. We have read of some cases where the steering box is turned all the way to one side but the wheels are still pointing straight. This is not a good thing when you are in a tight situation. Stephen’s cross-over steering allows the drag link to go from side to side rather than front to back. His kit uses a 1.25-inch drag link to connect the supplied pitman arm to the passenger side axle steering knuckle via an ORD heavy duty steering arm.

 

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To connect the passenger side OEM steering knuckle to the driver’s side, ORD provides a massive 1.5-inch tie rod. Both the drag link and tie rod are drilled and tapped (with both left and right hand threads) to allow the installation of heavy duty tie-rod ends. The supplied steering arm is super heavy duty! At close to 2 inches thick, it replaces the factory king pin spring cover as well as allows for a secure mounting location for the drag link. It has 5 holes drilled to attach to either a factory (4 bolt) knuckle, or a Dedenbear (5 bolt) knuckle. Stephen shipped us a set of high strength ARP replacement studs and new tapered nuts. The tips of the steering arms are tapered to prevent binding of the drag link while in a high flex situation.  Installing the kit is somewhat technical but is defiantly something you can do in your own garage. The first step is to remove the old fluid from the current steering system. You can either suck it out with a fluid removal kit or disconnect one of the hoses and drain it into a container. Doesn’t matter which way you choose because either way you’re going to make a mess!

With the fluid and the stock steering components removed, you should inspect the frame of the truck where the steering box was installed. It is very common for the GM frames to break in this area. In our case there were minor cracks that the previous owner had welded back together. To ensure the frame does not break in the future we installed one of Off-Road Designs steering box brace kits. This bolt on kit (with the exception of drilling one hole) adds a very strong brace from the main frame rail to the front cross member. It prevents the steering box from trying to twist the frame thus cracking it. The brace kit was easy to install. The main brace bolts through an existing hole in the front cross member with the other end sandwiching the frame to the rearward holes in the gear box.  This end of the brace is notched to allow the existing brake lines to remain in place.
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With the brace kit and new steering box installed it was time to install the new pump. This new pump does not have a reservoir built into it like the OEM pump does. A new reservoir needs to be mounted elsewhere. Changing out the pump can be a pain since you have to remove the old pulley and install it onto the new pump. There is only one way to properly do this and that is with a pulley remover tool. If you try to use a press or hammer to remove and install the pulley you will damage the new pump! Go to your local auto parts store and rent the proper tool! Even with the proper tool it is still a chore to remove the pulley especially since the tool we got was well used and kept slipping off. We ended up using a C-clamp to hold the tool one while we removed the pulley. Once the pulley is installed we installed the new pump into the truck.

Since the new PSC power steering pump does not come with a built-in resevoir it was now time for a little fab work to mount the new reservoir! PSC supplies the proper length hose to connect the pump to the reservoir. PSC has pre-measured the hose and it must remain at this length or shorter and the reservoir needs to be mounted as high as possible. We had a couple extra brackets lying around that we welded together to install the reservoir to the firewall. While it is a bit of a chore, the new PSC reservoir does hold a substantial amount of fluid and the extra hose length helps with additonal cooling.

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After some work the new PSC steering box is mounted on the frame. The ports for the ram are visible on the right side of the box. PSC highly recommends installing a cooler to keep the fluid from over heating and damaging the pump. We bought a high quality Earls cooler and mounted it next to the where the new transmission cooler will be mounted behind the truck’s grill. We ran the lines through the radiator core support and used a rubber grommet to prevent the hose from getting cut.
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The next step was to install the PSC ram cylinder, the rest of the hoses and the hose fittings. To mount the ram we used the supplied mounting tabs and welded them to the super heavy duty Great Lake Off-road differential cover. For the other end of the ram we first made a clamp that would be installed over the tie rod but, after some research, we decided that the clamp would probably slip on the tie rod. We then opted to weld tabs to the tie rod to ensure we would not have any issues with slipping.

Normally mounting the PSC ram cylinder to the differential cover would not be ideal. However the Great Lake Off-road cover is extremely thick so it makes an excellent place to mount one end of the ram. The brackets supplied by PSC were simply welded on the beefy cover and our mounting dilema was over.
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At first we were going to try to clamp the mount for the other end of the ram over the tie rod but decided against it. For maximum strength, we fabbed a couple mounts and welded the directly to the tie rod. Now we do not have to worry about the mount slipping. With the hydraulic hoses ready to be installed we routed them from the steering box, under the frame and down to the steering ram. We made sure to keep them out of the way of any parts that may pinch the hoses when the suspension flexes. To aid with this we secured the hoses to the frame just above the steering ram.
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These small dual hose clamps made mounting our hoses up and out of the way an easy task. They simply tap into anything and make an easy job of properly mounting our hoses out of the way. We also made sure that there is enough slack in the hoses that feed the ram to allow for suspension articulation.

The last step is to fill the system with fluid, bleed the system, and check for leaks. PSC has very detailed instructions on how to properly fill the system as well as bleed the system. If followed properly you shouldn’t have any issues with the newly installed hydro-assist steering system. Off-Road Designs also have very detailed instructions for installing the cross-over steering kit with every detail needed from proper orientation of the drag link to proper torque spec’s. Detailed instructions are very important for the average installer to use. We are glad PSC and ORD took the time to put these together!

 


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