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Hydraulic Assist: Creating The Perfect Steering For On- And Off-Road Driving

Posted in Project Vehicles on April 11, 2019
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When it comes to making your 4x4 more capable, a good set of tires and differential lockers are two of the best investments you’ll make. However, these upgrades can often come at a cost to your stock steering system. Given that most four-wheel drives were never engineered to handle much over a 33-inch-tall tire, it’s no surprise that adding oversized treads and a traction aid can overwhelm the stock steering. This is one of the reasons why bent steering links and broken sector-shaft failures are commonly seen on the trail.

There are actually a few options for improving any given 4x4’s steering system, but when it comes to balancing on-road handling and off-road performance, you’d be hard-pressed to beat a hydraulic-assist steering kit. The big draw of a hydraulic-assist steering system is that it allows you to retain the vehicle’s mechanical steering linkage, but it adds a hydraulic cylinder to relieve some of the pressure from the steering gear. This means you have the added steering force needed when aired down and fully locked off-road, and you’re able to retain the familiar feedback and feel of a traditional steering gear on-road.

We’re using a SG061R steering gear from PSC Motorsports with a reverse-rotation rack assembly inside. This gearbox is larger than the stock unit, but it bolts up to the S-10’s stock mounting location. This steering gear is not only stronger than the original box; it also allows us to have a forward-swinging pitman arm, which helps with the front wheelbase stretch.

Given that our ’01 Chevy S-10 is now resting on ARB Air Locker–equipped 1-ton axles and 40-inch-tall Nitto Mud Grapplers, we knew that a serious steering upgrade was in order. Since we still want to be able to easily drive this midsized pickup down the highway, a hydraulic-assist steering system was a logical choice. Of course, there isn’t exactly a vast aftermarket for S-10 steering upgrades. Thankfully, the steering experts at PSC Motorsports understood our needs and created a kit that would make our steering upgrade a painless one.

Since Low Range 4x4 in Wilmington, North Carolina, is playing host to our Crew Cab, we grabbed our gear and headed back to the shop for another round of work. While we still have plenty of items to check off of our to-do list, we’re inching closer to having a drivable rig. Be sure to keep your eyes peeled for more on this pickup, and read on to find out why building a heavy-duty steering system is much easier than you think.

The heart of the kit is an engine-driven P-series power steering pump. This high-flow unit reuses the stock 4.3L’s pump mount, so it can bolt to the original location.
The PSC pump is designed to take a stock pulley. This is ideal, as we are able to transfer over our OE pulley and reuse the V-6’s serpentine belt.
Since a hydraulic cylinder is added into the steering equation, more fluid will be needed. This is one of the reasons PSC provides a large remote fluid reservoir. To secure it to the truck, Low Range 4x4 owner Kelly Carter welded a small mount to the inside of the core support. This allowed us to bolt the reservoir in place.
While the pump is engine driven, it’s also gravity fed. This is why it’s critical to have the fluid reservoir mounted near and above the pump. Special care must also be taken so that the hoses don’t have any extreme bends or kinks.
Open space is limited under the S-10’s hood, so we removed the original airbox in order to provide the fluid reservoir with a proper mounting location. Replacing the filter is a washable cone unit that we picked up from our local parts store. It’s not the most ideal intake configuration, but it will work fine for our needs.
PSC provided this one-way vent for the fluid reservoir to ensure the fluid stays clean and won’t splash out of the housing. We tucked ours out of the way in a high location near the brake fluid reservoir.
For the axle’s steering links, we made life easy and picked up a full 1-ton steering kit from Barnes 4WD. This system comes with a drag link, tie-rod bar, inserts, and four 1-ton tie-rod ends. Since this is a cut-to-fit system, we measured our lengths and took the DOM tubing to the wet saw to chop down.
Factoring in the tie-rod ends and leaving room for adjustment, we MIG-welded in the provided tubing inserts. Since each bar gets a left- and right-hand insert, you can easily adjust the bars without unbolting them.
On the ’99-’04 Ford Super Duty high-pinion Dana 60, the stock tie-rod bar has a few bends in order to clear the differential cover. We wanted a straight bar for strength and were able to accomplish this goal thanks to Barnes 4WD offset 1-ton tie-rod ends.
For the drag link, Barnes provides a standard 1-ton tie rod along with a high-angle unit to ensure there’s plenty of motion as the front end travels. The fact that both bars are comprised of 1.5-inch-diameter, 0.250-wall DOM tubing means we shouldn’t have to worry about bending the links off-road.
We needed a pitman arm that could come as close as possible to our track bar frame-side pivot point, which is tucked tightly under the frame for clearance. We ended up with a Moog K6653 pitman arm. Given that it wasn’t originally designed for a 1-ton application, we used a tapered reamer to accommodate the new tie-rod end.
At the knuckle, we’re using a high-steer arm from Ujoint Offroad. While Ujoint sells the crossover steering kit with the 1-ton tie-rod taper on the top, we needed our drag link to mount below the high-steer arm. This meant drilling out the arm and installing a 1-ton tie-rod tapered insert that we picked up from Barnes 4WD as well.
The key to the entire hydraulic-assist steering equation is the cylinder itself. This ram is what alleviates the pressure from the sector shaft. PSC builds these for specific applications, as the axle, vehicle, tire size, and intended use are all factored in.
Using the provided weld-on tabs, we tacked the cylinder body mounts to our Barnes track bar bracket. Next, we cycled the steering from right to left to ensure we’d have an even amount of steering in both directions. Once the tabs were properly adjusted, we welded everything in place.
To plumb the cylinder to the steering gear, PSC provides hydraulic line and field-serviceable fittings that allow you to make your own lines. You’ll need a good cutoff wheel to cut the hose, but the fittings themselves can be installed using handtools.
Proper line routing is incredibly important. Too short and you could rip out a line or damage a fitting. Too long or not properly routed and you could smash the hose. We opted to route ours up and along the track bar. This will keep the lines out of the way and there is plenty of slack for them to travel.
Once the system was plumbed, we started the bleeding process. This required cycling the wheel a number of times, and then cranking the vehicle and repeating the process until the air was gone. We’re running the PSC-recommended Swepco 715 power steering fluid, as we have had great success with it in the past.
Our final setup is one that should give us trouble-free steering for years to come. We’ll be pulling the axle out soon for some final welding and to give everything a nice coat of paint. While we’re still a bit out from being able to hit the trail, we’re making great strides on our S-10. Be sure to keep an eye out for more installments of this build in an upcoming issue.

Sources

Nitto Tire
Cypress, CA 90630
888-529-8200
www.nittotire.com
PSC Motorsports
Azle, TX 76020
817-270-0102
www.pscmotorsports.com
Low Range 4x4
Wilimington, NC 28412
910-392-3204
www.lowrange4x4.com
Barnes 4WD
828-551-7616
barnes4wd.com

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