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AGR Rock Ram

By Mike "TXJEEPER" Cohn

and Jake Koetting

AGR Rock Ram
Fitting everything in on a TJ is a tough. It gets awfully tight in the front end. (click)

AGR Rock Ram
We fabricated a custom mounting bracket that uses 3 bolts on the back side to hold the sleeve in place. (click)

AGR Rock Ram
The only place we could get the Rock Ram to work was mounting it on the drag link. It just barely made it in there. (click)

AGR Rock Ram
Keeping the fluid lines out of the way took some thought. The wire-tie seen here didn't last long. Later, we devised a spring setup that keeps the lines up but allows droop when needed. (click)

AGR Rock Ram
The AGR gear box is the same size externally as the original box. (click)

AGR Rock Ram
Gear box in place.

AGR Rock Ram
Turning left up this crevace was child's play with the Rock Ram on-board, taking very little effort. (click)

AGR Rock Ram
The Rock Ram in action. (click)

So? How's it working out?
Thus far, the system has worked out quite well. The steering is once again tight and has very little wander while going down the road. At first, it was a bit scary to drive. We had so much slop in the steering prior to installing the AGR setup that even the most subtle movements of the steering wheel went unnoticed.

Because our previous setup was so sloppy, we also had more than our share of bump steer on the road. Those of you with TJ's are very familiar with the "death wobble." In addition to the wobble, we also had your run-of-the-mill bump steer.

The Rock Ram has replaced our steering stabilizer. Because of this, it acts as its own damper and absorbs most of the bumps we have encountered on the road. We did still have some bump steer, however, our suspension's conrtol arm caster was incorrect and the control arm bushings were completely shot, so slop abounded. I am very confident that with our new Skyjacker Rock Ready suspension, these problems will vanish.

Having the hydraulic ram, one would think that you could turn the wheel with your pinky. This is not necessarily true. AGR's setup for the TJ uses their smaller ram cylinder. What this does, basically, is bring your steering back to a more "normal" or stock feel. Steering our 35's is not much different from steering our other TJ, which is completely stock and running 30" tires. AGR can also revalve the cylinder to your liking and we may have them change ours to a slightly lighter feel. If you plan on running larger than 35" tires then you should consider a larger Rock Ram cylinder.

Of course, you're probably wondering how it performs off-road. This is an off-road magazine, right? We took the Project TJ to our local wheeling spot to have some fun. What I immediately noticed was that the information sent to me through the steering wheel was a little less discernable. In other words, you don't get quite as much feedback from the wheel as you do without the ram because your steering is now running the equivalent of Popeye on spinach. However, knowing what you are doing and the terrain over which you're doing it makes this not much of an issue.

The benefit of the Rock Ram, of course, is the ability to guide your rig over the rocks with ease. No longer are you having to battle the wheel to turn it. You turn the wheel and the tires go where you want them to. If you're stuck against a rock, you can even move yourself over. One caveat, of course, is to use your head and realize that the possibility of breaking parts doing this does exist.

Comments
We'll continue testing the Rock Ram and AGR steering setup over time. Long-term testing is necessary to really know how our custom mounting work will hold up. For now, everything's working great. As far as the custom bracketry we had to deal with goes, most TJ owners won't have to deal with as much if they are still running a stock or near-stock tie-rod and drag link setup. We may also consider running a cooler on our setup if we feel it needs it.

 

Now for the more technical version of what it is, courtesy of Jake Koetting...

With the number of TJ's on the trail increasing and running bigger and bigger tires, AGR decided to do something to help out the steering on these great machines. The stock TJ steering leaves owners longing for more power, especially after adding lockers, big tires, and driving in the rocks. In the past, AGR has come to the rescue with a large piston gearbox that increased the power to the wheels. More recently, they have added the "Rock Ram" system to their lineup for the guys who take rock crawling to the next level. The TJ was left out of the super-steering race for a while, due to its small power steering pump. Things have changed.

The stock power steering pump in the TJ doesn't produce the flow necessary to drive a large piston gearbox and a Rock Ram. Swapping in a larger pump takes some fabrication skills. To solve this problem, AGR is grouping their lower volume Rock Ram with an improved small piston (stock size) gear box and a bolt-in pump with much more flow than stock. The result is increased power on the rocks.

The gear box follows the new "Tri-Bearing" design with an extra bearing added to help stabilize the sector (output) shaft. At the other end of the sector, the stock cast aluminum hat has been replaced by a milled billet aluminum piece with the attaching hardware being safety wired in place for added security and good looks. This increases strength and rigidity, making it more difficult for the sector shaft to move around. The main benefit here is that this design helps eliminate some of the "slop" generally associated with steering gear boxes, giving the AGR box a quicker response and more precise control.

The stock cast aluminum cap at the end of the piston has also been replaced with billet aluminum milled with the AGR logo. The box has two ports added to the valve area to power the Rock Ram, making installation fairly simple. The box also features an additional mounting hole for those that wish to really anchor the box to the frame.

The pump is, externally, the same size and bolt pattern as the stock unit. Internally, however, it's a different ball game. This type of pump was originally designed for use with rack and pinion steering, which requires a much lower volume of fluid. With the pump in stock configuration, it is marginally adequate for use with a power steering gearbox.

Adding a ram cylinder to the stock system only magnifies the stock pump's weak points. AGR took this pump and beefed it up with larger internals that outflow the stocker by about 50%, from 2 gallons per minute up to 3. In addition, they've increased the pump's output pressure from 1350psi to 1500psi. The increased flow and pressure allows the AGR pump to power a gearbox and Rock Ram.

What is it?
The Rock Ram is basically a hydraulic cylinder that mounts between the axle housing and the tie rod. It gets fluid from the same valve inside the gearbox that controls the movement of the gearbox. This way, road feel is left intact. A purely hydraulic steering system allows no road feel. In contrast, most farm tractors are set up with hydraulic-only steering and are a bear to drive straight down the road. As a side benefit, the Rock Ram acts as an excellent steering stabilizer, helping to reduce bump steer. The Rock Ram increases the power at the wheels by over 100%.

With this set up, it is advisable to run a cooler for the power steering fluid. This adds more fluid to the system and helps to remove some of the heat that is inevitably generated running big tires in the rocks. In addition, a smaller pump pulley can be used to increase pump rpm and help turn the tires at idle.

The kit includes just about everything needed for installation on Jeeps with stock steering setups, however installing the kit does require welding.

AGR Rock Ram97-01 TJ Rock Ram Kit
Ram Gear Box
Rock Ram Cylinder
4 bolt 76 Case O-ring 3 inch piston (stock) TJ has 3 bolt case (extra bolt can be drilled)
Variable 3 1/8 Turns lock to lock
Tri bearing
Ram Fittings ported for more flow
Billet caps
Safety Wired
Ram TC pump
6 foot of 5/16 blue hydraulic hose
5/8 male rod end
5/8 female rod end
2 grade 8 5/8 bolts, washers, and nylon nuts
4 mount plates
4 90 degree JIC fittings

 

 

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