Project Retro F-350: AGR Performance Rock Ram

Dec. 06, 2010 By Jaime Hernandez
Project Retro F-350 with 40-inch BFG Mud Terrain KM2s.

Big wheels and tires can sometimes mean big sacrifice in steering. Fortunately it doesn’t have to be that way. 

As Project Retro F-350 began to shape up, we noticed the meaty 40-inch tires stuffed under the 1-ton axles were making steering a real challenge – especially when moving slow or stopped.

The factory power steering was having a heck of a time trying to swing that much rubber around. We also noticed the drop-down pitman arm was being stressed. It was time to fix what could become a problem and hopefully gain some more control on our steering.

The AGR Performance Rock Ram.

We contacted AGR Performance out of Ft. Worth, Texas. They specialize in high-quality power steering components for racing, hot rods and off-road applications.  They know their stuff pretty good—they’ve been in the business for over 18 years.

We were familiar with AGR Performance on competition rigs and hard-core rock crawlers.  We wanted to see if they had anything for the weekend warrior that goes mud boggin’ and hits the trails.

We spoke with Larry Szuhy at AGR Performance about our 1979 Ford F-350 and its steering woes. He suggested we try the AGR Performance Rock Ram system. The hydraulic assist and higher flow pump and heavy-duty gearbox would make turning the 40s much easier.

We liked the idea of having a hydraulic assist on our truck, so we gave it a shot.

Because of the vintage of the truck, we had to remove our factory steering gear box and hydraulic steering pump to send into AGR Performance. Cores are not readily available for these older trucks. AGR has most of the late model truck, 4x4 and Jeep parts in stock.  For a complete listing of applications, visit their website

Once AGR Performance had our parts in hand they re-worked them for more flow, added heavy-duty performance internals and completed the system with their AGR Rock Ram.


AGR Rock Ram system for 1979 Ford F-350 4x4 (Part# 352678K05)

We had a complete AGR Rock Ram system at our doorstep within a week’s time.  Inside two boxes were nicely packaged modified power steering components customized by AGR for our project.

The power steering pump starts off as a GM-based Saginaw model, but is transformed into a high-performance pumper that can flow two times the amount of factory pump. AGR adds their proprietary flow control valve, ring, rotor and veins to outflow the competition. Larry told us that a stock pump puts out about 2-1/2 gallons per minute, AGR’s pump will trump that with a 4 to 5-1/2 gallons per minute flow. How do you like them apples?

Above: Saginaw high-flow power steering pump from AGR Performance.

At first view, the steering box looked like it has just been tapped and painted. After talking to AGR, we got some more details of all the work that goes into making it a true Rock Ram system.

The factory Ford steering gear box was re-built, re-worked for more flow and tapped to allow hose fittings to direct hydraulic fluid to the Rock Ram hydro assist.

As Larry said, “Those other monkeys out there just tap the box and try to sell it as a rock ram – it’s not.” AGR goes to great lengths to make this a true performance ram assist. The steering gear box is beefed up with a heavy-duty sector shaft. The smaller ½-inch needle bearings are replaced with larger ¾-inch. Oversized stainless-steel balls are added to help guide the shaft; the inner housing is machined to open up the ports for increased hydraulic fluid flow. AGR also adds a heavy-duty valve and torsion valve. Lastly, they tap the box for it to work with the Rock Ram.

We were warned about inexpensive agriculture hydraulic assist being passed as rock rams by some “monkeys” out there. AGR has designed their proprietary Rock Ram specifically for Off-Road and 4x4 use. So don’t be fooled by ones taken off the tractor in the barn—they’re not the same.

The hydraulic assist, A.K.A. “ROCK RAM,” from AGR Performance.

Included hardware are high-pressure hose fittings, heim joints, grade 8 nuts and bolts and 1/8 steel tabs.

The AGR Rock Ram is a marble in itself, but we were blown when we found out it also doubles as a steering damper. AGR claims that the Rock Ram has shown to increase tire wear life and prevent coupling. So no more wandering or shimming down the road on your way to the trail or mud pit.
AGR Performance is as thorough about their installation instructions as they are about the parts they manufacture. We were pleased to get a step-by-step, 20-page manual that is easy to follow, even for the tree-shade mechanic.

We started off by bolting the pump onto the power steering pump bracket. Adding the pulley on the new AGR pump was next.

You will need a power steering pulley installation tool, don’t use a press—it will damage the pump.

The AGR Performance Steering gear box goes in next. Since we were using the original housing, everything bolted right up. No re-drilling of holes on the frame.

 AGR Performance High Performance Gear Box (Made in the USA).
One key measurement when installing the AGR Rock Ram is finding the center stroke on the rod.  You will want this to match up with your steering alignment for it to go straight when your steering wheel is centered.

Adam Young, our brother and mechanical mastermind, was nice enough to come over and give us a helping weld.

There’s some welding involved, so make a friend or take it to your local fab shop if you don’t have the skills.  You don’t want to chance not getting good welds and penetration on the tie rod and axle housing tabs. It’s what makes your Rock Ram … ram.

Esteban Hernandez, owner and builder of Project Retro F-350, tightens up the bolts attached to the axle housing tabs and the AGR Rock Ram before adding hydraulic hoses.

The hose and fittings provided by AGR make it easy to make a custom high-pressure hydraulic hose in your own garage. You just need a vise, some wrenches and patience—good music works too.

After all the plumbing is done, adding power steering fluid to the system and bleeding it will be the last major step. So before you get too excited and start your engine to drive up the hill next door, you need to do a good job bleeding the air out. 

The easiest way to do it is by lifting your front diff off the floor, so the tires don’t touch. You will then need to turn you steering wheel completely from left to right, and back again for about 40 cycles. Mind you, this is all done while the engine is off.  Make sure to keep an eye on the reservoir of our power steering pump—keep adding power steering fluid as needed.

Once the bleeding has ended, it’s time to start her up and see how well this AGR Performance system can turn those Mud Terrains.

Make sure to double-check fluid levels, bracket welds, and tension on power steering belt before and after testing. Our power steering belt was whining a little at full lock, the belt needed some adjustment. After it was all said and done, we were ready to hit the road.

The AGR Performance Rock Ram has dramatically improved steering on our Ford F-350 both on and off-road. We no longer have issues with turning the wheels while stopped or moving slow. The tension on the steering box and drop down pitman arm is also gone. The hydraulic assist from the AGR Rock Ram is throwing those massive 40s left to right with no problem.

Project Retro F-350 playing in the mud at Azusa Canyon, CA.

We are also happy to inform you that the AGR Rock Ram not only works good on the street and trail, it works flawlessly in the mud. 

We drove into some nasty, deep clay at Azusa Canyon. We were able to get into deeper mud and work the wheels around to gain traction with ease--one handed even. The AGR Rock Ram system has really increased our confidence in the truck, especially when we got into a sticky situation.

Final impression--we love it!

If you’re running 35s or larger off-road tires and are tired of your forearms getting bigger than your biceps, give AGR Performance a call so you too can gain control of your steering.

The folks at AGR Performance are great to work with. Our experience was excellent--they were very helpful before, during and after the project was completed.

AGR Performance, Inc.
4920 Rondo
Ft. Worth, TX 76106
Phone: 817.626.9006 Newsletter
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