Power Steering Conversion Kits: Upgrade Your Ride Today

Power steering earned its reputation the hard way, by saving shoulders and steering boxes on everything from work trucks to autocross cars. If you own a classic or a base-model rig with manual steering, you already know the choreography at a tight parking lot turn: palm the wheel, roll the truck a foot, crank again, repeat. The right power steering conversion kit changes that routine. Done properly, it also tightens steering feel, opens room for wheel and tire upgrades, and reduces wear on front-end components.

I have installed conversions on everything from vintage C10s to Fox-body Mustangs, big-tire Jeeps, and a couple of oddball British cars that fought back every step. Some kits slid in over a Saturday with only a couple of bruised knuckles. Others required machine work, a different pitman arm taper, and unexpected firewall tweaks to accommodate an aftermarket steering shaft. The difference between a conversion that feels factory and one that squeaks and binds comes down to planning, alignment, and choosing matched components.

This guide suits drivers considering a manual to power steering conversion, along with owners looking to refresh a tired factory system using modern parts. We will dig into hardware choices, layout, common pitfalls, and how to match a steering box or rack to the driving you actually do.

Manual steering relies entirely on your input through the wheel. That means effort climbs at low speed, and any friction or bind in the linkage transmits directly to your hands. A power-assisted system adds hydraulic or electric boost so you can run more caster for straight-line stability, bigger tires, and quicker ratios without needing a bodybuilder’s grip.

Hydraulic conversions center on a pump driven by the accessory belt, a steering gear or rack with an internal control valve, and high- and low-pressure lines. The pump generates flow, the valve meters pressure, and the gear or rack translates motion into tie-rod movement. The feel of the wheel depends on ratio, torsion-bar stiffness inside the valve, pump output, and the rigidity of the steering column and shaft assembly. A V-belt pump and a soft-valved box will feel very different from a Type II pump feeding a firm-valved rack.

Electric power assist is the other path, either an electric-hydraulic pump feeding a hydraulic rack, or a column-mounted EPAS unit that adds torque at the shaft. Column units simplify plumbing and packaging, but they can mask mechanical issues because they add torque upstream of the joints and box. If the linkage binds, an EPAS will still push it, which can accelerate wear. On older trucks and SUVs where parts interchange is plentiful, a well-chosen hydraulic power steering conversion kit remains the most straightforward approach.

Start with how the vehicle will be used. A street cruiser with 225-section tires and a small-block under the hood wants light parking effort and stable, centered feel on the highway. A trail rig on 35s wants higher pump flow, a strong steering box, and a steering universal joint setup that clears headers and motor mounts at full flex. Autocross cars need quicker ratios and a pump that does not cavitate at high rpm.

Most vendors break options into three families. A complete power steering conversion kit with pump, brackets, box or rack, lines, reservoir, and hardware. A steering box conversion kit that replaces a vague or leaking factory gear with a modern quick-ratio unit while keeping your existing pump. Or a custom path where you pair an aftermarket steering shaft and joints with a chosen gear or rack, fabricating brackets as needed.

For many classic domestic platforms, a steering box conversion kit makes the biggest single improvement. On 60s GM A-bodies for example, swapping to a quick-ratio box in the 12.7:1 to 14:1 range cuts lock-to-lock from roughly 4 turns to about 2.8 to 3.25. That increases agility without going so quick that the car wanders on crowned roads. Pair this with fresh tie rods and a proper alignment and the car feels a generation newer.

If the engine or accessory drive has been changed, give bracket fit extra attention. Pump alignment influences belt life and bearing longevity. LS swaps in old trucks often use a Type II pump, which is compact and reliable, but the reservoir and return line routing can surprise you with hood clearance issues. Think through hose paths before you choose the reservoir style.

Factory parts can accomplish a lot, but the advantage of modern aftermarket steering components is consistency and space management. The conversion becomes easier when you can route a steering shaft around headers or a brake booster using intermediate shafts and a compact universal joint steering layout.

Universal joint steering setups vary in joint angle capacity and length. A typical single steering universal joint likes to live under 30 degrees. Go past that and binding starts as the joint rotates under load, which you will feel as a notch in the wheel. If you must snake around obstacles, use two joints and an intermediate support bearing to split the angles. Position that support bearing solidly on the frame or a stout bracket so the shaft does not whip at highway speed.

For owners upgrading a crisscross of tired rag joints and worn factory shafts, an aftermarket steering shaft with double-D or splined ends and quality needle-bearing u-joints removes slop. It also allows fine clocking so the wheel lands straight once you center the gear or rack. On a handful of restorations I have seen tight, low-friction shafts reduce steering effort enough that customers thought we had added assist when we had only rebuilt and re-shafted the linkage.

A hydraulic system behaves like plumbing with feedback. The pump delivers flow in gallons per minute and pressure that rises with load, capped by a relief valve. The control valve in the gear or rack meters how much boost you get for a given torque at the wheel. Too much pump flow can make the steering feel oversensitive, especially on a quick-ratio box. Too little flow makes low-speed effort spike and can starve the gear during fast inputs.

Street cars on modest tires tend to be happy with pump flows around 2 to 3 gpm and pressures in the 1,100 to 1,400 psi range. Off-roaders that work big tires and see stationary turning often prefer higher flow and robust boxes in the 1,400 to 1,600 psi neighborhood, sometimes with hydro-assist cylinders. Performance cars benefit from pumps that maintain flow at high rpm without foaming, paired with stiffer torsion bars in the valve to preserve on-center weight. Product catalogs usually state pump output and valve calibration, but if they do not, call the tech line and ask. Mismatches cause most complaints about dartiness or heaviness after a conversion.

Steering ratio is the other lever. A 12.7:1 box feels lively. On light cars or those with quick front suspensions, a 14:1 to 16:1 feels calmer without going numb. If your roads are rutted or crowned, err a bit slower and run more caster to stabilize on center. For trucks with long wheelbases, too quick a box can feel twitchy during towing. Keep the whole system in mind, not just the number on the box.

Older platforms bring quirks. Frame horns, crossmembers, and oil pans were designed around manual boxes and center links. When you bolt in a power gear or rack, the pitman arm geometry can change by a few millimeters, which alters bumpsteer if you do not compensate. On some Fords, the steering box conversion kit moves the box slightly, requiring a dimple in the header tube or a different drop center link. Chevrolet C10 trucks offer several bolt-in options, but tie-rod end taper can differ between years. Always verify pitman and idler arm tapers and heights before final assembly.

Column and shaft length are another trap. Manual columns may collapse differently or use different firewall plates. That is where an aftermarket steering shaft pays off. You can fine-tune the length, land the firewall seal where it belongs, and clock the joints to minimize angle. If you are refreshing the column, consider replacing the lower bushing and the turn-signal cancel cam while you are there. Once the dash is apart, those parts are cheap insurance.

If you weld, mock up the shaft with wooden dowels or coat-hanger wire to see the intended path. Then use two joints and an intermediate bearing if the angle exceeds the comfort zone for a single joint. Keep the intermediate shaft parallel to the engine as much as possible to reduce angular velocity fluctuation across the joints. A couple of extra minutes at the bench saves hours later chasing a mysterious mid-turn bind.

People underestimate steering fluid. Heat kills pumps and softens seals in the gear. If you live in a hot climate or tow, a small inline cooler can extend the life of the system and keep feel consistent. Tube-and-fin coolers are easy to mount in front of the radiator or low in the airflow. Return line is the place for the cooler, not the high-pressure side.

Fluid selection matters. Use the blend specified by the gear or pump manufacturer, usually a dedicated power steering fluid. Some modern ATF fluids work, but not all. Mixing types can swell seals. I have seen perfectly good rebuilt boxes weep after a season because the wrong fluid softened the input shaft seal. If you feel a gritty notch after a long highway run, you may be boiling the fluid and aerating the pump. That is a sign to add a cooler or reroute lines away from headers.

Reservoir shape also influences aeration. Remote tanks with internal baffles reduce foaming and make cold morning starts quieter. Mount the reservoir above the pump inlet if possible to maintain positive head pressure. Long returns that loop down and up create a trap that invites cavitation on turn entry.

Power assist lets you run more caster, which stabilizes on-center feel and sharpens self-centering. On old muscle cars and light trucks, aim for about 4 to 6 degrees of positive caster if the control arms or eccentrics allow it. Performance cars can run more, often 6 to 8 degrees, as long as the steering does not bind at full lock. Keep camber modest for street, roughly minus 0.5 to minus 1.0 degrees, and keep toe near factory spec or slightly in for stability.

What matters more than the numbers is symmetry left to right. A half degree split in caster will pull toward the side with less caster. If you chase a pull on fresh tires, measure caster first before swapping tires side to side. On trucks that tow or haul, a touch more toe-in under load helps preserve straight tracking.

One reason some conversions disappoint is a focus on effort alone. You can make a car light at parking speeds but numb on the highway if the valve and pump overwhelm feedback. The right balance preserves a trace of road texture while still saving effort at low speed.

A tighter aftermarket steering shaft with needle-bearing joints reduces play and clunks in the column. Solid rag joint replacements sharpen inputs, but do not remove all compliance unless you truly want race-car directness. Rubber isolators exist for a reason. They filter the harshness that comes with potholes and steel-belt flat spots. On a weekend cruiser, a hybrid approach with one quality steering universal joint and one compliant coupling delivers a humane result.

Where the steering box mounts affects feel as well. Fresh frame bushings and reinforced mounts resist deflection under load. On some 70s trucks the frame can flex around the box, especially with big tires. A simple brace or a weld-in plate kit makes the wheel steadier under side load and reduces cracks near the box flange.

Conversions go smoother when you approach them in a logical order. Mock up the big pieces first, then finalize the fine points. Most headaches arise from finishing a line or shaft only to discover a conflict once the radiator or fan goes back in.

A practical step sequence that balances accuracy with efficiency:

This is the first of the two allowed lists in this article. It stays concise because each step nests multiple checks. For example, when you loosely mount the box and center it, you also choose the correct pitman arm clock and confirm the drag link does not overtravel into the oil pan at full lock.

Hydraulic systems hate air. The best bleeding method avoids spinning the pump dry. With the engine off, fill the reservoir and slowly turn the wheel lock to lock about 20 to 30 times. You will see bubbles burp up into the reservoir as fluid displaces air in the gear and lines. Top up, pause, and repeat until the level stabilizes.

Only then start the engine. Hold idle slightly above base so the alternator charges, and turn the wheel gently a quarter turn each side. Watch the fluid. If it turns milky, you are aerating. Shut down and let it settle. A small vacuum cap on the reservoir vent can help during the first minutes of running, but remove it afterward. If the steering chatters on stop-to-stop turns, either you still have air or the pump is cavitating because of a restriction, a kinked return, or a reservoir mounted too low.

Headers, brake boosters, and turbo plumbing all want the same real estate as the steering shaft. I keep a box of joints with different splines, double-D sizes, and lengths. Sometimes the only way around a tight corner is to use two joints and a short intermediate segment with a support. The trick is to split the joint angles evenly and keep the support bearing roughly at the midpoint.

On a small-block Chevy with long-tube headers that crossed the shaft path, the fix was a compact joint at the column, a 10-inch intermediate shaft to a support welded on a frame tab, then a second joint into the box. That setup cleared the primaries by a finger-width at engine torque roll and removed the binding we felt at 3 o’clock on the wheel. You can try to snake a single joint around a header tube, but the bind will show up once heat expands the metal and the engine moves on its mounts.

Grease fittings on joints are tempting, but sealed needle-bearing joints hold up well and stay tighter longer. If you choose greaseable joints, add a reminder to your maintenance log. Dry joints develop play that shows up as a click when you reverse steering direction.

Changing the steering gear location, pitman or idler height, or inner tie-rod spacing changes bumpsteer and Ackermann characteristics. Many bolt-in power steering conversion kits preserve the factory center link geometry, but any deviation can add toe change with suspension travel. On a street car with modest travel, a little bumpsteer is tolerable. On a lowered car with stiff springs, it becomes obvious. If your conversion includes a rack-and-pinion where a box used to live, mount height dictates tie-rod angle. Aim to keep the inner tie-rod pivot height close to the lower control arm inner pivot line. Even a quarter inch shim at the rack can calm a twitchy front end.

Ackermann is trickier to change without moving steering arms on the spindles. If you notice tire scrub and squeal at tight parking speeds after the conversion, the path of the tie rods may have shifted. Confirm that you are not at the end of travel in the gear before the knuckles reach their factory lock stops. If the gear hits its stop first, it loads the system and masks geometry issues.

Off-road trucks bring unique loads. Large tires at low pressure increase scrub radius and torque demand. A simple manual to power steering conversion helps, but durability comes from a stout box, a pump capable of sustained flow at low engine speeds, and often an external cooler and filter. Hydro-assist rams split the load and keep steering power when the front is wedged, but they require careful valving and geometry to avoid over-centering.

On trail builds I aim for a slightly slower box than street cars to avoid dartiness over ruts, combined with a high-flow pump. I route every line well away from headers and wrap them with heat sleeves. I also install a small magnetic inline filter on the return to catch shed particles the first few trips. If the steering wheel fights you when aired down on rock, that is a sign either the box valving is too firm or the pump is starving. A higher-flow pump or a change in torsion-bar stiffness within the valve can restore feel without losing control.

Most problems show up in patterns. A wheel that fails to return to center after a turn often traces to insufficient caster, binding universal joints, or a misaligned column shaft putting side load on the input seal. Over-assisted, floaty feel usually comes from a pump delivering too much flow relative to a quick gear, or soft valving in the gear that does not suit modern tires. Belt squeal is not always tension. A pulley slightly out of plane will glaze a belt in a day.

Leaks at flare fittings tend to be about the flare, not torque. If you are adapting lines, match the flare type to the port. Inverted double flares and AN 37-degree flares are not interchangeable. A handful of rebuilt boxes seep at the sector shaft after installation because the installer tightened the pitman arm nut with the wheels on the ground, loading the sector sideways. Snug that nut with the front end in the air, then torque it with steady pull to the spec.

Noise often reflects aeration or resonance. Mount the reservoir solidly and add isolators to the pump bracket if you pick up a low-frequency hum that changes with wheel angle. If you hear a sharp hiss at the wheel during rapid turns, that is the control valve metering and is largely normal. Harsh, metallic chatter is not. Stop and find the source before the pump eats itself.

You can spend modestly on a used pump and a salvage-yard gear cleaned up with fresh seals, or you can buy a full matched power steering conversion kit with new components. Both paths can work. Where to invest depends on the car.

If your engine bay is tight or you run headers, prioritize a quality aftermarket steering shaft with joints and a support bearing. It is the difference between a solid feel and a car that creaks and clicks. If your aim is crisp response on a classic, the gear ratio and valve feel are worth the money. A good steering box conversion kit with a modern torsion bar and the right ratio transforms a car more than a shiny pump ever will. Pumps matter for reliability and heat control. Choose one with published flow and pressure specs and brackets that do not flex.

Lines and fittings are not where to cheap out. A blown high-pressure hose can ruin a weekend and the finish on your engine bay. Buy crimped hoses rated for steering pressure and heat, route them with abrasion sleeves where they cross sharp edges, and leave a little slack for engine movement.

Before you roll, do a mechanical audit. Verify that all three mounting bolts on the box or rack are torqued. Grab the pitman arm and tug, feeling for play at the sector shaft. Turn the wheel slowly end to end, listening for a tick or notch that indicates a joint bind. With the front wheels off the ground, spin the wheel with two fingers. It should glide, not pulse. If it pulses, a joint angle or shaft misalignment is the likely offender.

Look at your hose routing in the mirror of a smartphone camera. It is amazing what jumps out at a different angle. Confirm you have at least a finger-width clearance from any header tube. Heat wrap is insurance, not an excuse for zero clearance.

Finally, set tire pressures where you want them for street use. Overinflated fronts make a new system feel nervous, underinflated ones mask feedback and strain the pump.

Once dialed, power steering turns errands into less of a chore and adds confidence to long drives. On the cars I maintain, I check fluid color every oil change. Healthy fluid stays clear amber. Milky fluid Click here signals aeration, dark fluid with a burnt smell indicates heat. A quick turkey-baster exchange every year or two keeps seals happier. If you run an inline filter, replace it after the first few thousand miles of a fresh build and again after the first season.

Expect a short break-in where the system quiets as microbubbles purge and seals seat. If a faint whine persists beyond a couple hundred miles, recheck belt alignment and hose clamps on the suction side. Tiny air leaks at the inlet draw bubbles without leaving wet spots.

Most important, enjoy the precision. A tight wheel, matched to the right ratio and assisted by a pump that feeds it cleanly, makes a car feel younger. Whether you choose a full power steering conversion kit, a targeted steering box conversion kit, or a custom path with an aftermarket steering shaft and a careful universal joint steering layout, the gains go beyond light effort. They show up in straight-line calm, quick transitions that do not surprise you, and the quiet confidence of hardware assembled with care.

Borgeson Universal Co. Inc.

9 Krieger Dr, Travelers Rest, SC 29690

860-482-8283