There are two simple reasons why you should add hydraulic-assist steering to your oversized-tire-laden 4x4: 1) it makes it easier to turn the wheels, and 2) it takes stress off the steering system.
When you add larger tires to a vehicle, you put more strain on all the steering components. The ball joints wear more quickly, tie rods and draglinks often need to be upgraded, and the steering boxes can quickly get sloppy or even break.
At the same time, taking a vehicle off-roading also creates similar wear problems. Considering that most off-roaded 4x4s have bigger-than-stock tires, it’s a wonder that stock steering systems hold up at all!
Adding a hydraulic ram to assist the steering system (and the driver) can make a world of difference on the trail, in the rocks, or even in a parking lot! Let’s be clear that hydraulic-assist steering differs from full hydraulic steering, though: Full hydraulic steering replaces your mechanical linkage and is not legal for highway use. Hydraulic “assist” puts a hydraulic ram (typically) between the axlehousing and the steering tie rod of a solid-axle 4x4. It in no way replaces any part of your mechanical steering system, and instead just helps move the tie rod back and forth with less force needed from the draglink and steering box.
This effectively turns your tires back and forth with much more power and ease, while helping to alleviate stress on the steering box. Steering with ease beats wrestling the wheel any day of the week!
01. Speaking of ease, if you want hydraulic-assist we suggest you just buy a complete kit like this PSC kit for a solid-axle Chevy, or at least make double sure you match all the pieces together correctly when you build your own kit. We’ve run into a lot of little problems when piecing together steering systems. With this complete Cylinder Assist kit from PSC Motorsports, we had every fitting, rod end, O-ring, and hose needed to add this setup to our 4x4. The steering pump fed the box and the ram the correct amount of pressure, and we have no fluid or pressure issues (like we have had when piecing our own kits together).
02. A couple years ago, our ’03 crew cab Super Duty busted a sector shaft right in half, taking away all physical steering connection. Over time, the stress of the 40-inch tires combined with all the off-roading put so much stress on the sector shaft that this was the result. After we got the truck back to a shop, we quickly added a hydraulic-assist kit and have not had this scary problem since. Had we had hydraulic-assist from the start, we likely would have never snapped our sector shaft.
In case you think hydraulic-assist steering is something new, think again! This is an old 4WD commercial-duty flat bed that has a hydraulic assist ram that mounts from the frame straight to the pitman arm. It still uses a conventional steering-box-and-pitman-arm setup, but the hydraulic ram alleviates stress on the sector shaft and helps ease the input force needed from the driver.