Prerunner Steering: Hydraulic Assist, Swing Sets & Heim Tie Rods

Prerunner steering upgrades replace weak factory tie rods with chromoly heim-jointed links and often add hydraulic assist so the front end can survive the loads, wide track, and big tires that come with a long-travel build. The right setup depends on how far you widen the truck, tire size, and whether it still sees the street.

Once you widen a front end, stock steering becomes the weakest link, and it usually fails at the worst possible moment. If you are planning or already running a long-travel front end, start with our long-travel suspension guide and the wheels and tires guide, because steering geometry, track width, and tire size are all one connected problem. This page breaks down the steering hardware that keeps everything pointed straight when the suspension is cycling through 12 or more inches of travel.

Why long-travel front ends need steering upgrades

When you install a long-travel kit, the wheels move outward and cycle through far more travel than the factory ever designed for. Two things happen. First, the factory outer tie rods and their small ball-joint ends become a stress concentration point, and loads always travel to the next weakest component. Second, the added travel exaggerates bump steer, the tendency of the wheels to steer themselves as the suspension compresses and extends, because the tie-rod arc no longer matches the control-arm arc.

That is why nearly every reputable kit from Total Chaos, Camburg, and Dirt King either includes or strongly recommends a matching steering upgrade. Strengthening the arms without addressing the tie rods just moves the failure downstream.

Heim-jointed tie rods: the first upgrade

The most common starting point is a heim-joint (rod-end) tie rod upgrade. These kits replace the factory outer tie rods with large chromoly links running to high-strength heims, which handle misalignment through big suspension arcs far better than a sealed ball joint.

• Rod-end size matters. Total Chaos-style Tacoma and 4Runner kits are commonly reported to use roughly 7/8″ chromoly heims, while some race-oriented kits may run smaller 3/4″-class heims. Bigger is generally stronger, but must clear the knuckle and wheel, so confirm the exact spec with the manufacturer for your application.
• Double-shear mounting. Quality kits include weld-on double-shear tabs at the outer tie-rod location so the joint is supported on both sides instead of cantilevered.
• Fab is usually required. Most of these kits require welding and grinding, so budget for a shop unless you weld. Our fab shop directory is a good starting point.

Heim tie-rod kits often run in the low hundreds of dollars, making them one of the best value upgrades on the list, though pricing varies by brand and platform. On a mild build with tires up to roughly 33-35 inches, this alone is often enough.

Inner tie rods and spacers

Long-travel kits usually add tie-rod extensions or relocate the inner pivot to correct geometry for the wider track. High-misalignment spacers on the heims let the joint articulate further before it binds, which is what actually protects the part at full droop and full stuff.

Hydraulic assist: single vs dual rams

As tires grow past roughly 35 inches and the truck gets heavier and wider, muscling the wheel gets harder and the factory steering box or rack takes a beating. Hydraulic assist adds a ram driven by a high-output pump that shares the steering load, dramatically reducing the effort and stress on the box.

• Single-ended ram (ram assist). One cylinder mounts between the axle/frame and a steering arm. It is simpler, cheaper, and the most common choice for a street-driven prerunner. Complete kits from established brands can commonly land anywhere from roughly $1,400 to $3,500 or more depending on pump, box, and ram size, so treat any figure as a rough ballpark.
• Double-ended ram (full hydro-assist). A through-shaft cylinder pushes and pulls symmetrically, giving more balanced assist and force. It is favored on heavier, higher-horsepower, or race-focused trucks running very large tires.

An important note: the hydraulic ram provides far more stabilizing force than any bolt-on steering stabilizer shock. On a properly built hydro-assist truck, extra stabilizers are mostly cosmetic. Also, full hydraulic steering (no mechanical link at all) is generally not street legal and is race-only, so most street-driven prerunners stick with mechanical steering plus assist.

Rack vs. box and swing-set steering

Prerunners are built off either a rack-and-pinion or a steering box, and the choice drives the rest of the design.

Swing-set (or “swinger”) steering is the advanced option: an intermediate pivoting linkage is designed so the tie-rod arc mirrors the suspension arc, effectively canceling bump steer through the whole range. It is the gold standard on serious chassis builds but requires full custom fabrication and is overkill for a mild street truck.

Which steering setup for your build?

Match the steering to how far you have taken the front end and how the truck is used.

• Mild, street-driven, up to ~35″ tires: A heim-jointed tie-rod upgrade matched to your long-travel kit. The steering upgrades that ship with Total Chaos and Camburg kits are engineered for exactly this and are the safe path.
• Heavier truck, 35-37″+ tires, high steering effort: Add single-ended hydro assist on top of upgraded tie rods. Pair it with a Dirt King long-travel front end and it stays composed at speed.
• Race-focused or big-power desert truck: Double-ended ram assist and, on a full chassis, swing-set steering. This is custom-fab territory, so lean on a proven shop from our fab shop directory.

Platform matters too. Toyota builders will find the deepest catalog of bolt-in heim kits, which is worth keeping in mind if you are still choosing a base, covered in our Tacoma prerunner build guide.

Frequently Asked Questions

Do I really need a steering upgrade for long travel?

In almost all cases, yes. Widening the track and adding travel overloads the factory tie rods and worsens bump steer. At minimum, a heim-jointed tie-rod kit matched to your long-travel suspension is considered mandatory for reliability.

What does hydraulic assist actually do?

It adds a hydraulic ram, powered by an upgraded pump, that shares the steering load with your box or rack. This cuts steering effort with big tires and greatly reduces stress on the steering box, and it stabilizes the front end far better than a bolt-on stabilizer shock.

Is hydro-assist steering street legal?

Hydraulic assist (which keeps the mechanical linkage) is typically street legal, though you should confirm local rules. Full hydraulic steering with no mechanical connection is generally race-only and not street legal, which is why most dual-purpose prerunners run assist rather than full hydro.