Great off-road ability, decent street manners and safety were our main goals when we set out to build our project Jeep. Well, the off-road part we nailed almost dead on. Decent street manners, well we came close, it stops good and tracks straight. Safety, its got a full roll-cage that was professionally installed, racing harnesses, and great seats. Everything worked like it should right up to the point when I made the first emergency maneuver in traffic. WOW! Talk about touchy steering, the great power steering that worked so well on the rocks was way too touchy on the street.
Enter AGR Steering Inc. After a lengthy discussion with Matt Burkett at AGR it was decided that an AGR super box II was in order for the Jeep. This steering gear box is similar in many ways to AGR’s original Super Box in brute power, but is engineered for the off-road enthusiast who uses his Jeep for daily driving on public roads. This unit uses a large piston, but has a variable 17:1 to 13:1 turning ratio. The valving is designed for more firm and precise steering effort. This gives more stability and control at highway speeds and less over steer off-road. The unit also helps stabilize larger tires and gives a more stable feel on the street. This all sounded exactly like what the Jeep needed. Matt also suggested that we use AGR’s Super P series pump. This pump is designed to be used in conjunction with the Super Box 1 or 2. A larger cam pack with larger rotor and vanes enables this pump to flow 3.4 gallons per minute and produce 1500 psi. A custom ported housing makes for less flow restriction, allowing the pump to run stronger and cooler. This pump when used with the Super Box will increase the amount of steering force to your tires approximately 65%. Each unit is assembled with all new internal parts and Hydrogenated Nitrile (HNBR) seals to insure a long life and leak free performance.
Does it work you ask? The Jeep is now as smooth and controllable on the street as any new passenger car. The variable ratio steering box works exactly as it should, it is very controllable at highway speeds and has very low effort when crawling on the rock trails of Arizona. The new box also tightened up the feel of the Jeep on rough high-speed washout roads. The pump runs smooth and quiet, and also powers a Milemarker hydraulic winch. Look for a full story on the Milemarker winch in an upcoming review.
Installing the AGR Steering Box is a matter of simply removing the old steering box and installing the new one. Sounds simple right? Well it also means disconnecting all of the power steering lines, the steering shaft, the box brace, and separating the pitman arm. Once all of this is done, the box can be removed from the frame and the brackets disassembled from the steering box. In our case this entire process took about 4 hours. We ended with a stripped nut stuck inside the frame and struggled with numerous frozen bolts. There’s no such thing as a simple job with a Jeep. Once the box and brackets are removed from the frame, remove the brackets from the box and thoroughly inspect all the brackets for cracks. The brackets are subjected to a tremendous amount of stress and are often cracked around the bolt holes. If there are any cracks, either weld them up or replace the entire bracket. Transfer the brackets to the new AGR Steering box and install the assembly back onto the frame. Reinstall the pitman arm on the new box and torque the nut to the recommended torque. Reconnect all of the steering lines and the steering shaft now.
Drain the power steering reservoir by disconnecting the return line form the back of the reservoir and draining the fluid into a suitable container. There is really no way I have found to change a power steering pump without making a mess, so have plenty of shop rags around to clean up the fluid. Remove the old pump and reservoir from the brackets. The new AGR pump does not include a reservoir, so you must remove the old one from your pump and install it on the AGR pump. You must also remove your pulley and install it on the new pump. You will need to have a pulley separator tool on hand to remove the pulley without damaging it, so if you don’t have access to one they should be available for rent at your local auto parts store. You will need to install the new seals included with the pump and then put the reservoir back on the pump. I have found that a small dab of grease will help hold the gaskets in place during this process. Now reinstall the pulley, and all of the brackets back on your pump, and install the entire assembly back on the engine. Hook up the hoses, replace the power steering belt with a new one, and fill the reservoir with synthetic power steering fluid. The new pump requires synthetic fluid due to the high flow rate and the amount of heat it generates. Once everything is back in place and connected, jack up the front end of the vehicle to begin to bleeding process. You will need two people to accomplish this. Have your helper start the engine and slowly cycle the steering wheel from lock to lock. While they are cycling the wheel, watch the fluid level and add fluid, as it is pushed through the system and the air is forced out the level will begin to drop. After the system is air free, install the reservoir cap, check for leaks in the system and take it out for a test drive. You should notice the difference as soon as you turn out of the garage. The true test is when you get the vehicle up to highway speed and the wandering has diminished. You can now enjoy years of trouble free driving knowing that your steering system is ready for anything you throw its way.