Attention: TDR Forum Junkies 
Since this truck is driven empty 99% of the time, it rides really rough on our local roads. After riding in my friends ‘04 4WD Cummins, which rides smoother than my 2WD, it was obvious that a change was necessary. I spent about 6 months evaluating other systems, reading anything on the TDR or other sites that would help. I was looking mainly at a way to smooth out the ride as well as control axle wrap during acceleration. Wheel hop is severe at times so this was an absolute must. I thought about adding the “assist” type air bags and removing a leaf or two, but then I would have to add traction bars to stiffen up the rear. I looked at the high quality 4 link “K” brand, but it was just more than I wanted to spend. In the end, the Roadtamer system looked like the best mix of ride & axle wrap control along with an acceptable price. This system was reviewed in the TDR mag issue #51.
I dealt with the manufacturer directly and their representative was always available and willing to answer my questions even before I bought the system. The system includes 2 beams, 2 air bags, a panhard bar, a 1 degree shim, 4 U bolts and Nuts and all tubing and fittings and hardware as well as an air compressor and auto-leveling sensor. No tank is used. Initially they sent the wrong Heim joint for the panhard bar, but after a phone call, the correct one was sent out UPS red. The system is capable of being “dumped” so that you can lower the bags completely. I wired up my own switch for system control. I do not leave it on normally because it will adjust frequently when changing from flat ground to uphill terrain. There is a built in 30 second delay before any height change is made when the system is on.
All the pieces of this system are very beefy and met my expectations for strength. Installation of the two beams is the easiest part. You just unbolt and remove your old springs and bolt the beams in place using the original front spring perch and bolt it to the axle. The rear perch is reused to attach the plate that forms the upper support of the air bag.
The difficulty comes when installing the upper bag supports and the panhard bar. There are self tapping bolts and shims included for the bag supports, but I made my own custom spacer blocks and had to drill completely through two of the holes because the self tappers stripped out in the frame. Snaking the nut into the frame rail was not too bad. I just tack welded a piece of wire to the nut and fed it through the nearest hole.
The panhard bar is the most difficult thing to install. It requires a 3/4” hole drilled in the inside of the left frame rail as well as two through 1/2” holes. The 3/4” hole only goes through the inside section of frame. A bushing goes through this hole and seats against the outside section. A 1/2” hole through to the outside continues from there. This method allows the bracket to be clamped securely to the frame rail without crushing it. When finished, there are three 1/2” bolts holding the bracket to the frame.
Pinion angle became a big deal. After three attempts to get the angle where it should be, I ended up with 1 degree shim on each side to roll the pumpkin down. 1 shim was included and the other had to be made on the Bridgeport.
Installation of the compressor and controls is described best by the photos. The compressor is in the right front wheel well. The remote air intake for the compressor is plumbed up inside the bed where the air is dryer and cleaner.
As part of this system, the manufacturer also recommended a set of Rancho 9000 shocks all around. They were set to the softest setting initially.
Installation took me roughly 2 Saturdays. Hurrying is not in my nature. This is definitely NOT a project to be done by someone without lots of tools and machinery.
Positive view after 30 days of use:
The ride is definitely smoother. The front is also noticeably softer with the ranchos. The rear is still not as nice as I was hoping for, however the reality is that it is much better than before. People can now ride in the back without getting bounced out of the seat.
Due to the stiffness of the beams, there is almost no body roll when going around a corner. I mean this truck does not lean at all. Feels like riding in a corvette when cornering. This system would be great for anyone that has a slide-in camper. I can corner at much greater speeds than before, with complete confidence in control.
The dump control is great for getting under a low trailer ball rather than cranking up the tongue and the truck always sits at the same height regardless of load.
Minuses:
Because of the design of this system, when you take off briskly (to the floor) as these Cummins are capable of doing, the suspension completely extends. In other words, as the wheels turn forward, the axle housing will roll backwards due to the torque reaction. This is really annoying because it will lift the back of the truck to the maximum extension of the bags. I made a gauge to measure this. The air bag extends 6” from its normal “at rest” position. That equates to about 3-1/2” of lift at the rear bumper. The biggest problem with this movement is the fact that the pinion rolls "up" and increases the angle beyond a safe limit. The truck vibrates considerably under hard acceleration.
The wheel hop problem, which easily occurs with this truck, gets really bad when going around a corner under moderate acceleration. It causes the back to violently buck up and down. I feel like a frog hopping down the street when this happens. Part of this is due to the worthless LSD. If one wheel starts spinning, the truck stops pulling, the truck comes down and grabs and then jerks forward and up and on and on.
Needless to say, this was an unacceptable condition. Besides compromising the drivability, it has to be hard on the drive train. The manufacturer says that they have only had one other person complain about this condition and it was on a 12 or 13 sec truck. They had no recommendation for a fix. I don’t think my truck is that fast either.
My solution was to put a set of Beard suspension limiting straps on, so that maximum travel of the suspension is controlled. These were installed this past weekend. I custom fabricated a bracket and welded it to the beam on each side. The top is just anchored in a hole in the top bag support plate. As of this writing, it has helped immensely, however I still have to tune the shocks to get maximum stiffness without hurting the ride. The rears are set to the middle setting right now. I can now take off in a straight line without wheel hop. In hindsight, this is probably not the best way to go to control axle wrap. I don’t really feel like I have this issue under control yet. However, it sure has helped smooth out the ride, and for that it is worth it. I will continue to improve this system if possible.
I welcome any questions or comments.
Jim
I dealt with the manufacturer directly and their representative was always available and willing to answer my questions even before I bought the system. The system includes 2 beams, 2 air bags, a panhard bar, a 1 degree shim, 4 U bolts and Nuts and all tubing and fittings and hardware as well as an air compressor and auto-leveling sensor. No tank is used. Initially they sent the wrong Heim joint for the panhard bar, but after a phone call, the correct one was sent out UPS red. The system is capable of being “dumped” so that you can lower the bags completely. I wired up my own switch for system control. I do not leave it on normally because it will adjust frequently when changing from flat ground to uphill terrain. There is a built in 30 second delay before any height change is made when the system is on.
All the pieces of this system are very beefy and met my expectations for strength. Installation of the two beams is the easiest part. You just unbolt and remove your old springs and bolt the beams in place using the original front spring perch and bolt it to the axle. The rear perch is reused to attach the plate that forms the upper support of the air bag.
The difficulty comes when installing the upper bag supports and the panhard bar. There are self tapping bolts and shims included for the bag supports, but I made my own custom spacer blocks and had to drill completely through two of the holes because the self tappers stripped out in the frame. Snaking the nut into the frame rail was not too bad. I just tack welded a piece of wire to the nut and fed it through the nearest hole.
The panhard bar is the most difficult thing to install. It requires a 3/4” hole drilled in the inside of the left frame rail as well as two through 1/2” holes. The 3/4” hole only goes through the inside section of frame. A bushing goes through this hole and seats against the outside section. A 1/2” hole through to the outside continues from there. This method allows the bracket to be clamped securely to the frame rail without crushing it. When finished, there are three 1/2” bolts holding the bracket to the frame.
Pinion angle became a big deal. After three attempts to get the angle where it should be, I ended up with 1 degree shim on each side to roll the pumpkin down. 1 shim was included and the other had to be made on the Bridgeport.
Installation of the compressor and controls is described best by the photos. The compressor is in the right front wheel well. The remote air intake for the compressor is plumbed up inside the bed where the air is dryer and cleaner.
As part of this system, the manufacturer also recommended a set of Rancho 9000 shocks all around. They were set to the softest setting initially.
Installation took me roughly 2 Saturdays. Hurrying is not in my nature. This is definitely NOT a project to be done by someone without lots of tools and machinery.
Positive view after 30 days of use:
The ride is definitely smoother. The front is also noticeably softer with the ranchos. The rear is still not as nice as I was hoping for, however the reality is that it is much better than before. People can now ride in the back without getting bounced out of the seat.
Due to the stiffness of the beams, there is almost no body roll when going around a corner. I mean this truck does not lean at all. Feels like riding in a corvette when cornering. This system would be great for anyone that has a slide-in camper. I can corner at much greater speeds than before, with complete confidence in control.
The dump control is great for getting under a low trailer ball rather than cranking up the tongue and the truck always sits at the same height regardless of load.
Minuses:
Because of the design of this system, when you take off briskly (to the floor) as these Cummins are capable of doing, the suspension completely extends. In other words, as the wheels turn forward, the axle housing will roll backwards due to the torque reaction. This is really annoying because it will lift the back of the truck to the maximum extension of the bags. I made a gauge to measure this. The air bag extends 6” from its normal “at rest” position. That equates to about 3-1/2” of lift at the rear bumper. The biggest problem with this movement is the fact that the pinion rolls "up" and increases the angle beyond a safe limit. The truck vibrates considerably under hard acceleration.
The wheel hop problem, which easily occurs with this truck, gets really bad when going around a corner under moderate acceleration. It causes the back to violently buck up and down. I feel like a frog hopping down the street when this happens. Part of this is due to the worthless LSD. If one wheel starts spinning, the truck stops pulling, the truck comes down and grabs and then jerks forward and up and on and on.
Needless to say, this was an unacceptable condition. Besides compromising the drivability, it has to be hard on the drive train. The manufacturer says that they have only had one other person complain about this condition and it was on a 12 or 13 sec truck. They had no recommendation for a fix. I don’t think my truck is that fast either.
My solution was to put a set of Beard suspension limiting straps on, so that maximum travel of the suspension is controlled. These were installed this past weekend. I custom fabricated a bracket and welded it to the beam on each side. The top is just anchored in a hole in the top bag support plate. As of this writing, it has helped immensely, however I still have to tune the shocks to get maximum stiffness without hurting the ride. The rears are set to the middle setting right now. I can now take off in a straight line without wheel hop. In hindsight, this is probably not the best way to go to control axle wrap. I don’t really feel like I have this issue under control yet. However, it sure has helped smooth out the ride, and for that it is worth it. I will continue to improve this system if possible.
I welcome any questions or comments.
Jim
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