Steering Assist & Stabilizers
Updated November 13, 2007
I have not put a stabilizer on my truck. This subject has come up a couple of times over the last 5 years. I don't think it's needed on a Hummer. If your front end is shaking there is something wrong. The thing that did seem to interest me if you are doing a lot of off roading where you are cranking your steering around against a lot of resistance is a hydraulic boost cylinder on the steering. This would be in a lot of heavy mud or turning your wheels while jammed in the rocks. I got interested in these because I've been through 3 steering boxes on my truck; all under warranty. I don't know why they went because I'm very careful about forcing my wheel. When my extended warranty runs out in a year I'll probably install one of these systems.
There are 2 kinds of systems. One that uses the cylinder alone and one that is an assist. Technically you are not allowed to use a steering system on the road that doesn't have a physical connection between the steering wheel and the front end. This means that an assist type of system would be nice to have. You also should get better tie rods because these systems can move heavy rocks.
Yes it will work... it is a hydraulic ram setup, very common on off-road rigs with oversized tires. AGR has developed these "Rock-Ram" setups for the Hummer, I spoke with them about it a couple of years ago. The only problem with it due to the use of the ram is that the steering will not return to it's straight ahead position on it's own. You have to steer it straight. I just posted some pictures they sent me of a Hummer with the AGR setup on it here:
Yes the existing power steering gear box needs to be rebuilt or replaced to a racing gear box that has 2 extra fittings for the ram...The power steering pump must also be rebuilt or replaced to a high flow pump with an external reservoir and filter to avoid a vortex.....Then the frame is reinforced with 4130 chromaloy to avoid the gear box from being pulled from the frame...The frame also needs to be added to so the ram will fit and run close to the steering linkage....And last the steering linkage gets a mounting brace (4130 chromaloy) welded to it....Most of this requires welding....
Now the heim is a replacement tie rod that is made of 1" 4130 chromaloy with 7/8" heim joint ends that do not need to be greased and can hand 230,000 psi..... This is a good thing to do even if you don't do the steering kit.
AGR Rock Ram Installation
by John Andres
I finished up an AGR Rock Ram installation on my newly acquired '93 this weekend. The rock ram is basically a hydraulic piston that supplements the steering box by providing additional power to the centerlink. AGR sells a kit ($800 Four Wheel Parts after 20% coupon). The kit includes a new power steering pump, a new steering gearbox and some hydraulic lines. It includes some mounts meant to be MIG welded to the frame, I decided to make my own. Pictures enclosed.
There has been some "talk" about the difficulties of the installation, mine was pretty straightforward. It can be done in stages, and the vehicle can be driven between stages, so it doesn't have to be done in a long day. Basically, you replace the gearbox, the power steering pump, and install the ram piston. The gearbox is a standard Saginaw gearbox with two additional fittings for the ram piston.
Since I installed IROK 42's, I decided to put the box knowing that the strain of 42" tires might ruin the current box or break the gear bolts/frame leaving me stranded. I looked at doing the new ALPHA box, but liked the idea behind the Rock Ram.
There aren't any Hummer specific directions in the documentation so I called Kevin in tech support at AGR. He said most people weld the included mounts to the frame but thought that the frame on a H1 had a zinc coating making it difficult to weld. I decided to use some square tubing and bolt it to the frame. Kevin installed a rock ram on his jeep (37" MTR's) and said that the steering stabilizer benefit was pretty awesome.
Since my ride is pretty much torn apart (see photo), installation was pretty easy. I had already removed the AC components so I removed the power steering pump, pulled off the pulley (pain) and attached the old reservoir to the new pump, reinstalled the pulley and put it back on the truck. The new gearbox replaces the old. It has 2 new fittings for hoses that connect to the ram piston. These can be closed off (with included caps) so you can disconnect the ram in the field if you break a mount. The real issue is what to do with the piston, which is easy once you figure it out (why I wrote this and included pics). I fabricated a mount out of 3/16" square tubing (about 2x3x9") and bolted it to the frame near the gearbox using two grade 8 1/2" bolts. After straighten the wheels forward, I pulled the piston (no lines attached) out half its travel distance or 4". I cut a plate of steel about 4"x6", drilled a 5/8" hole in it for the piston mount and drilled 4 holes in it for some U bolts for temporary fitment to the centerlink. Bolted it to the center link and turned the steering lock to lock to check for clearance - no problem. Removed the centerlink (tie rods, pitman and idler), took it to the bench and MIG welded the plate to the centerlink (bought a MIG welder this past week). Removed the U bolts and trimmed unnecessary metal from the piece, smoothed any sharp edges, cleaned it with brake cleaner and painted it.
AGR supplies you with hydraulic lines and end fittings so you cut it to length and install it (easy). They use reverse threads. Since I just did a 4.5" body lift I recently created new lines because the lines on my '93 wouldn't allow a lift of more than a couple of inches. The two new lines go from the gearbox to the piston. After the lines are connected, I lifted the front of the vehicle and turned the steering wheel (engine off) lock to lock about 25 times to bleed the system of air.
I haven't been able to field test the Rock Ram system yet. Sitting on a milk crate, I have driven around the back yard and driveway and can tell you that steering is effortless on hard pavement. It did take significantly more effort before installation. I am anxious to take it on the trail as soon as I finish the rest of the project.
Mounting location bolted to the frame
If your looking into installing a Hydraulic Assist, stay away from AGR's setup. I just had my unit installed today by a reputable race shop with SIGNIFICANT modifications to make it work. First, the Ram was too long for the steering geometry: over an inch too long. The ram wasn't even 'matched' to the new steering box. The box had to be rebuilt again and steering stops had to be added to match the ram so it would not tear apart the steering links and tie rods. Now with the Ram being too long, that had to be rebuilt to shorten its travel. So with the rebuilding of AGR's setup, it added another 4 hours of fabrication time r/r'ing this unit, which in turn just adds to the cost of it. Its a poorly matched setup. The only part that was good was Lynch's billet clamp for the steering link. Even the power steering pump and volume isn't enough to power the unit correctly.
In order for the unit to work correctly. The shop added a remote reservoir w/ filter and a higher output steering pump for more volume to fill up that ram. They also added a smaller steering pump pulley to pump the fluid faster for the ram. So for the same same amount of money spent on AGR's setup a different setup could have been purchased by another manufacturer called Howe Performance Power steering ( the ones that make the remote reservoir). So for the individuals that want to just add a remote reservoir w/filter and a stronger steering pump, I'd go with Howe's. Even that would benefit the Hummer.
In conclusion, the AGR setup is a poorly put together package not matched for the Hummer steering geometry. If installed without the mods aforementioned, the AGR setup would damage/destroy the steering system. The ram wanted to push beyond the steering stops. You could actually see the stress being put on the steering components due to poorly matched steering box and a Ram that was too long. Even the steering box mounting points were flexing when turned to full stops. But now it is so much easier to turn the wheel from a standstill, lock-to-lock. I'm hoping this will save many idler and pitman arms in the future.
If you want info on Howe's steering components, here's the link:
(no affiliation with this company)
I'm going with the Howe's Performance setup. He's done a few Hummer's (H1). At the moment, I have their pump, remote can w/filter and remote cooler. I dumped the AGR pump, the only item left is AGR's Ram and gear. According to Howe's tech, they've rebuilt a few of AGR's boxes due to the zinc flaking off inside due to scuffing and clogging up the insides. I'm already experiencing problems with the gear, at slow speed turns it feels like I'm not getting any assist at all and then all of a sudden it kicks in.. Howe's Performance are also starting to 'valve' the hydro boost to allow for better flow when the brakes are used. That looks like the route I'm going down the road when this AGR system craps out.
From Lynch Hummer a Rock Ram Dealer:
We installed the Rock Ram on my '96 almost 2 years ago and had no problems with the installation nor have we had any problems with the unit since. This Hummer is used extensively off-road and the extra assist comes in handy.
We have sold about 10 - 15 kits and this is the only problem we have heard of.
AGR was sold:
You see, Jeff has more than just a vested interest in PSC. Jeff worked for a while at AGR which his family owned. Jeff's dad, Tom, sold his stake in AGR in November of 2001 then formed PSC in September of 2002. PSC is rapidly becoming the who s-who in the power-steering world with products which can be seen in and take the abuse from track racers and even in the most brutal of off-road rigs."