Power steering conversions can feel straightforward on paper. Swap a manual box for a power unit, run a pump, plumb hoses, align the column, done. Then the truck hits a rutted trail, the steering wheel bucks, and the new setup groans like a tired winch. This is where ram assist earns its keep. Ram assist bridges the gap between a conventional power steering conversion and a full hydraulic steering system, offering more muscle at the tires and more authority at the wheel without giving up on-road manners.
I have fitted ram assist to solid axle 4x4s, to classic trucks with big tires, even to a couple of diesel-swapped wagons that turned into front-heavy bulldozers. The pattern repeats. A basic power steering conversion kit gets you most of the way there. Ram assist finishes the job, if it is selected and installed with some restraint and a clear understanding of geometry, hydraulic limits, and the steering shaft’s ability to transmit torque without binding.
What ram assist actually does
A conventional power steering system relies on a hydraulic pump, a steering box with a spool valve, and the tie rod linkage to convert steering input into wheel angle. The box has to generate all the force that pushes the tires against the ground. Add tire diameter, beadlocks, lockers, rocks, and the box starts to struggle. Operators feel it first as slow response at idle, fading assist when hot, or hammering kickback through the wheel.
A ram-assisted system adds a double-acting hydraulic cylinder between the axle housing and the tie rod, plumbed to the steering box so that hydraulic pressure on the ram matches the direction of the wheel input. The steering box still meters flow and provides mechanical feedback. The ram simply multiplies the available force at the tie rod. You keep a steering column connected to a steering box, you keep return-to-center and road feel, but you lower the stress on the box sector shaft and the pitman arm while reducing driver effort.
If full hydro steering is a new word to you, think of ram assist as a half step. Full hydro eliminates the steering box and column connection to the wheels. Ram assist keeps them, and that distinction matters for legality and road manners.
When a power steering conversion is enough
Many manual to power steering conversion projects stop sensibly at a power steering box, pump, hoses, and the necessary bracketry. On a stock or lightly modified vehicle with 31 to 33 inch tires, one locker or none, and modest front axle weight, a well-chosen steering box conversion kit will feel like a revelation. A typical Saginaw-style pump puts out 1,200 to 1,400 psi and 2 to 3 gpm at idle. With a competent box and tight linkage, that works fine.
I like conversions that start clean. Replace worn tie rod ends, align caster and toe, and address the column. The original rag joint and column lower bearing often hide more steering slop than the old box. An aftermarket steering shaft with quality needle-bearing U-joints, sometimes called a steering universal joint assembly, removes the rubbery feel and gives the new box a solid partner. You do not need a ram to mask worn parts. Fix the fundamentals first.
Signs that ram assist would help
A truck tells you when it wants more. The signals are consistent.
- The steering wheel stalls at idle against a curb or rock even though the pump and box are healthy. You can hear pump whine, and the effort required at the wheel spikes. The system runs hot off-road, boiling fluid after repeated lock-to-lock events, especially with 37 inch tires or larger. Kickback through the wheel feels sharp and violent, enough to sting your palms or jerk your thumb. A properly set ram damps that impact by sharing the load. The truck tracks fine on the highway but steers reluctantly at trail speeds with the front locker engaged. Once you unlock, the resistance drops. That delta points to torque demand outpacing the box. Sector shaft failures or frame cracks near the box mount appear after you have already reinforced the area. The ram reduces the bending moment on the sector shaft and the frame.
Those symptoms do not automatically mandate a ram. A pump with more flow and a box with a larger torsion bar and better valving may solve the issue. Sometimes a fluid change to a high-quality mineral-based power steering fluid with proper viscosity stabilizers helps. Caster angle, scrub radius, and tire pressure matter too. But if you are carrying a heavy front bumper, winch, and 40s, or you do slow technical work with the wheels bound, ram assist becomes less of a luxury and more of a safeguard.
Mechanical layout that works in the real world
Ram placement drives how the system behaves. The cleanest setup ties the ram body to the axle housing via a truss or welded bracket and attaches the rod end to the tie rod near its midpoint. That way, the ram acts nearly in line with the tie rod and does not add a twisting load. When packaging forces the ram onto the tie rod and the axle spring perch or diff cover, pay attention to two angles. The ram should be parallel to the tie rod through the steering sweep, and it should not bottom out or top out before the knuckles hit their mechanical stops.
Ram stroke should match knuckle travel. Many solid axle trucks use rams in the 1.5 inch bore, 6 to 8 inch stroke range for 35 to 37 inch tires. Larger tires and deep-offset wheels may justify a 2 inch bore, but bore size affects flow and response. Bigger bore equals more force for a given pressure, but it also means more fluid volume to move. With a stock pump and box, oversizing the ram can slow steering and increase heat.
It is tempting to mount the ram where it is easy to weld. Resist that. I once reworked a setup on a leaf-sprung 4x4 where the ram sat at a 20 degree upward angle. It worked lock-to-lock in the shop. On the trail, the axle drooped, the angle changed, and the rod side-loaded the cylinder. Seals blew in two trips. After moving the mount to clear the diff cover and track the tie rod, the same ram lasted for years.
Hydraulic considerations that separate good from problematic
The steering box becomes the metering brain. You tap the box for assist ports, typically on the pressure and return cavities tied to the internal spool valve. You must port the correct locations so the ram pushes and pulls in sync with the box output. Many boxes have known porting guides, and good rebuilders prep them for assist. A mismatch creates fight between the box and the ram and will feel awful.
Pump output must match the combined demands of the box and the ram. A common Saginaw Type II pump with the right pulley and relief spring will support most ram-assisted builds. I have run 1.5 inch bore rams on a stock TC pump on small block swaps, but idle response lagged. Increasing pump speed via a slightly smaller pulley, within belt traction limits, often fixes low idle sluggishness. Upgrading to a high-flow pump helps, but plan to manage heat with a cooler mounted in good airflow. Expect fluid temps in the 180 to 220 F range during hard work. Above that, seals suffer and assist fades.
Hose size and routing matter more than most first-timers think. The ram lines carry full system pressure and a lot of flow during quick steering events. Use quality -6 or -8 lines rated for 2,000 psi or more, with abrasion sleeves where they cross near the track bar or spring. Route with enough slack for droop and stuff, and check at full stuff and droop with the wheels turned both directions. Secure lines so they do not act as bumpstop straps. If you run a hydroboost brake unit, remember it also draws from the same pump. Matched components become critical. A pump that is marginal on flow will show its weakness when you steer and brake hard at the same time.
Fluid choice is not glamorous, but it decides how your system ages. Some OEMs spec ATF for power steering, others specify dedicated P/S fluid. For mixed components, I favor a high-quality power steering fluid meeting CHF or OEM-level requirements rather than a random ATF. Pick one fluid and stick with it. Bleed thoroughly. Tiny bubbles hide in the ram and the box for longer than you think. Cycle the system with the front axle on stands, engine off, then engine on, then recheck. Expect to top off several times.
Valving, feel, and why the steering shaft still matters
People chase brute force, then complain that their truck feels numb. The fix is not always smaller tires or less caster. It starts with the box torsion bar and spool valve. A box with a softer torsion bar opens the hydraulic ports quicker and gives lighter effort but less on-center feel. With ram assist, many builders prefer a slightly stiffer torsion bar to preserve feedback. This is a judgment call. A rock-only rig can prioritize low-speed assist. A daily-driven classic needs better on-center.
That brings the conversation to the column and the shaft. The weakest link in steering feel is often the flexible coupler. An aftermarket steering shaft using quality double-D or splined sections and precise universal joint steering couplers removes wind-up. If the column angle is steep due to suspension lift or body mounts, consider a two-joint setup with a support bearing. A steering universal joint that operates near its angular limit binds and adds a notchiness that owners sometimes misattribute to ram sizing. Keep joint angles reasonable, align phasing, and grease if the design requires it.
I have corrected more than one sketchy conversion by redoing the shaft and joints alone. Once the steering input becomes crisp, you can better judge how much assist you actually need. That is important if you are considering an aftermarket steering components shopping list. Aim first for precision, then add force.
Comparing manual-to-power conversions with and without a ram
If you are starting with a manual box and planning a manual to power steering conversion, you face a decision. Install a power steering conversion kit and evaluate, or plan from the start for assist. The conservative path is sensible for vehicles under 5,500 pounds with tires up to 35 inches. Choose a steering box conversion kit that is either assist-ready or has enough sector shaft strength to survive later ram porting. Some boxes, notably late model truck boxes with large sector shafts, accept assist well. Others need internal mods and stronger sector bearings.
The total parts picture shifts when you add a ram. Borgeson Universal Your pump bracket and belt routing must drive a pump that can handle higher duty. Your steering cooler increases in importance. You need room on the axle for the cylinder and tabs. You need to verify clearance to the track bar through the entire cycle. That extra labor is best done once, so if you suspect your use case will demand a ram within a season, plan mounts and hose paths during the initial conversion even if you cap the ports for now.
Ram size and pump capacity pairing that avoids regret
A practical pairing table would look neat, but vehicles vary. Instead, anchor your choice to tire diameter, curb front-axle weight, and intended use.
For 33 to 35 inch tires on a 4,500 to 5,500 pound vehicle that sees mixed road and trail, a 1.5 inch bore, 6 inch stroke ram, a box with a medium torsion bar, and a 3 gpm capable pump works well. You keep good response at idle and reserve for repeated turns without boiling fluid.
Move to 37s with lockers on a 5,500 to 6,500 pound rig that works in rocks, and the same 1.5 inch bore ram with an 8 inch stroke can still do the job if the pump flows 3 to 4 gpm and the cooler is sized appropriately. The box should be assist-ported by a reputable shop, and the pitman arm and drag link ends should be in top condition.
At 40s and beyond on a heavy rig, you enter the zone where a 2 inch bore becomes a candidate. Expect to upgrade to a high-flow pump, possibly with a remote reservoir to prevent aeration, and add a large cooler. Steering speed may slow slightly at idle. Many owners accept that trade to gain the authority to turn when bound up.
Oversizing the ram without matching pump and cooler is a common mistake. You feel it as a lazy wheel, rising fluid temps, and foaming. Fixes include more pump speed, higher displacement pumps, or stepping back to a smaller bore. Forced fixes never feel as good as a balanced system designed from the start.
Frame reinforcement and bracket sanity
Power multiplies loads. A manual box mounted to 50-year-old frame rails might have lived happily with a bit of flex. Add a power box and a ram pushing on the tie rod, and the box mount becomes a lever arm. Box plates or weld-in sleeves where bolts pass through the frame keep cracks from starting. On older domestic trucks, the area around the forward box bolt is a known weak spot. On Jeeps with unibody rails, steering box reinforcement plates on both sides with sleeves are insurance, not bling.
Ram brackets deserve the same attention. Weld to structure, not thin tabs. Gusset intelligently so that force carries into the axle casting or truss without creating a stress riser that cracks later. If you are not comfortable welding to a cast center section, use a truss that spans the axle and pick up your mount there. The rod end mount on the tie rod should not compromise the tie rod’s strength. Avoid drilling huge holes that become crack starters. If you need a clamp-on solution temporarily, run high-quality clamps designed for steering loads, then plan a proper welded tab when you next service the axle.
Steering geometry still rules the day
Ram assist is not a bandage for poor geometry. Bump steer stems from mismatched track bar and drag link geometry. A ram can mask the steering effort change, but the axle will still steer itself through the travel if the bars are not aligned in length and angle. Caster that is too low for highway use, say 2 degrees after a lift, will reduce return to center and make the truck wander. Increasing caster to 4 to 6 degrees on many solid axles helps straight-line stability and steering feel. Scrub radius that grows with deep-offset wheels increases steering effort and kickback. Those fundamentals do not care whether you have a ram.
During mockup, set the truck at ride height, aim for parallel track bar and drag link, check tie rod height relative to the ram body, and plan clearance to the diff cover and sway bar. Only after those boxes are checked should you weld permanent tabs.
The role of aftermarket steering components and shaft choices
The best hydraulic assist in the world cannot compensate for a steering column that twists like a licorice stick. An aftermarket steering shaft with double-D or splined connections and tight universal joints is a small upgrade that pays huge dividends. It sheds the mushy feel of rag joints, resists torsional wind-up, and reduces column lash. If your conversion changes column angle, you may need a two-joint setup with an intermediate support bearing. This is common on body-lifted trucks and on engine swaps that relocate the steering box. Look for a shaft with serviceable joints and corrosion protection. Cheap joints without true needle bearings develop notchiness quickly, and that feel percolates through the whole system.
Pair those with quality tie rod ends or heim joints where appropriate. On road-driven rigs, sealed tie rod ends remain the safer bet. For rock-only rigs, heims with proper misalignment spacers can work, but they transmit more vibration. Match the pitman arm taper to your drag link ends. Slop here multiplies in the wheel.
Universal joint steering assemblies in the column also need correct phasing. If you have two joints, keep the yokes aligned and the angles equal to minimize velocity fluctuation. When phasing is off, you feel a cyclic notch as the wheel turns, and owners sometimes blame the ram.
Dealing with legality and inspection reality
In many regions, ram assist is acceptable on road-registered vehicles because there remains a mechanical link from the steering wheel to the wheels through a steering box. Full hydro often fails inspection because it lacks that mechanical link. If your area has inspections, verify the position directly. Insurance carriers and inspectors are more concerned about line routing, hose chafe prevention, and secure brackets than about the presence of a ram. Keep your work neat, use proper fittings, and secure lines every few inches with clamps that do not cut into the hose jacket.
A short, practical build path
You can start with a power steering conversion kit, evaluate, then add a ram if needed. The cleanest experiences follow a sequence.
- Refresh the front end. Replace worn joints, correct caster, set toe, and install an aftermarket steering shaft with quality joints to remove slop before you judge assist needs. Choose a steering box conversion kit that can be ported for assist or purchase a box pre-ported by a trusted rebuilder, and pair it with a reliable pump and a cooler. Mock up the ram with the axle at full bump and full droop, steering from lock to lock, to ensure no side loading or stroke mismatch. Tack tabs, test again, then weld fully. Plumb with properly rated hose, bleed thoroughly, and monitor fluid temperature during the first serious outing. Add cooling if you see sustained temps above roughly 200 F. Reassess valving and torsion bar feel only after everything else is right. If the wheel feels too light, consider a stiffer torsion bar or smaller bore ram before chasing pumps.
Troubleshooting that saves weekends
If the wheel turns slowly at idle, check pump speed and flow first. A slightly smaller pulley within belt traction limits often helps more than a pump swap. If assist fades after heat soak, suspect aeration. Look for foamy fluid, check reservoir return placement, and verify the return dumps below the fluid line. If the truck pulls on-center, do not blame the ram first. Swap ram hoses left to right temporarily. If the pull reverses, the ram seals are bypassing. If not, you are likely chasing alignment or box centering.
Chatter under light steering loads often traces to hose routing near the track bar. The bar and hose can resonate together. Move clamps, add a section of isolation sleeve, and the noise disappears. Kickback that remains violent with a properly sized ram and 28 to 32 psi tire pressure usually means scrub radius is excessive or the track bar bracket is flexing. Fixing either reduces shock far more than increasing ram bore.
Where universal joint steering angles become a hard limit
Lifted rigs with body lifts or engine conversions can push the steering shaft angle beyond what a single U-joint likes. When the joint runs consistently above about 30 degrees, it binds and adds heavy spots in the rotation that owners confuse with hydraulic issues. Two joints with a support bearing spread the angle and smooth rotation. Keep both joints under roughly 20 degrees and phase them. This is not optional if you care about feel. The added benefit is reduced stress on the lower column bearing. Once the shaft rotates smoothly, you can fine tune ram size and box valving for effort and feedback.
A note on parts synergy
Glossy catalogs encourage buying parts in isolation. Better results come from a matched set. A steering box conversion kit intended for a universal application might ship with a pump that is technically adequate but marginal for a ram and hydroboost combination. Pairing a box prepared for assist, a pump with the right relief and displacement, a cooler with proper airflow, and a ram sized to your tire and vehicle weight avoids the domino problems that chew up time and money.
Similarly, the steering universal joint arrangement and aftermarket steering components around the linkage should be viewed as part of the same system. Slop anywhere grows into uncertainty everywhere. If you have a hard budget, invest first in the box, the shaft, and the geometry. Add the ram once you know you need it.
A real-world example that earned its keep
A customer with a 1978 K10 on 37s came in complaining that his recent manual to power steering conversion felt fine on the street but hopeless on the trail. The build had a rebuilt Saginaw box, a V-belt pump, and a decent linkage. On inspection, the rag joint showed cracking and the column angle was too steep for a single joint. We installed an aftermarket steering shaft with two U-joints and a support bearing, ported the box for assist, and mocked a 1.5 inch bore, 8 inch stroke ram on a truss. The pump got a smaller pulley and a dedicated stacked-plate cooler with airflow. After a thorough bleed, idle response improved. He ran a full season before reporting any issue, which turned out to be a loose tie rod clamp. The ram took the hammering away from the box, the steering stayed linear, and the wheel no longer snapped on granite edges. That K10 still drives to the trail.
Final guidance grounded in use
A power steering conversion kit solves 80 percent of the work when moving from a manual box. Ram assist covers the other 20 percent for heavy, tall, or big-tired builds that live in technical terrain. Choose a steering box that can be ported, size the ram to your tire and weight instead of your ego, and support the hydraulics with a pump and cooling that keep up. Protect steering feel by tending to the column, the aftermarket steering shaft, and universal joint steering geometry. Respect the frame, weld good brackets, and keep lines safe. If you do those things in that order, ram assist turns from a buzzword into a durable, confidence-building upgrade that makes your hands and your truck last longer.
Borgeson Universal Co. Inc.
9 Krieger Dr, Travelers Rest, SC 29690
860-482-8283