Opinion on Track bars

[kattkisson]

Has anybody installed a Trackbar on a P-30 chassis?  This is the bar that would connect the leaf spring bridge plate to the opposite side frame for advertised increased stability. Blue Ox calls theirs the "Tigertrak".


If the bar attached to the Differential pumpkin I can envision how it would work.  However it appears that the one designed for the P-30 is as described above and I can't see how it allows for the different lengths necessary for suspension travel.  Any experience out there? Pricey-but if it works???

[HamRad Mobile]

Good morning, kattkisson; 

     The track-bar, Panhard bar, "Tiger-Trak," et cetera. 

     The goal is to keep the rear axle assembly located at a fixed position from side-to-side under the middle of the chassis or frame even while the axle is moving up and down with the rear suspension system.  Or, alternately, the frame or chassis is kept in a fixed position above the middle of the rear axle assembly. 

     The problem appears when you are going around a turn or making a direction change when driving the motor home.  Ever have a little sports car dive in front of you going across the gore area when it is trying to get to the exit ramp before you, even when you are not taking that exit?  (Come to think of it, that is not limited to just little sports cars.) 

     The problem appears when you are making that turn, and centrifugal force wants to keep the vehicle going in the same direction while the front wheels are trying to get it to turn, and the rear of the motor home moves over along the rear axle toward the outside of the turn.  This is even more noticeable when you have a long "over-hang" with the chassis and motor home body behind the rear axle.  I have 11.5 feet of "over-hang" back there. 

     The length of the rear leaf springs and the mountings for them do allow some side-to-side play or motion between the rear axle and the chassis or frame.  You will feel this as a need to make some correction with the steering wheel to keep the motor home in its lane during a turn or on the course you want for it, which can include an avoidance maneuver to prevent contact with that diving sports car or other vehicle going for the exit ramp.  Sometimes this "unexpected additional steering input" is described as the "tail wagging the dog" handling effect in driving a motor home. 

     The Panhard bar is designed to keep the axle and frame fixed side-to-side relative to each other, and while it is not truly perfect, it does a really good job of accomplishing that.  The main point is the simple geometry of the length of the Panhard bar as the suspension system allows the axle to move up and down.  The Panhard bar is about 3.5 feet long, and there is very little change in the actual radial length displacement of the end of the bar in the small arc as the axle end of the Panhard bar moves up or down in what will be about a maximum of a four inch total up and down movement.  This really does help hold the axle and the chassis or frame together in one tight package with little side-to-side movement.  The sway bar also does a similar function between the axle and the chassis or frame with fore-and-aft movement, in addition to rolling or twisting between the axle and the chassis or frame. 

     Do I have a Panhard bar on my Winnebago Elandan WCP31RT yet?  The true answer at this time is "no," but I do have one in stock that will go onto it when the exhaust system modified conversion is complete.  Even without the exhaust system modified conversion that I am making, the stock GM exhaust system must be changed to take out the exhaust pipe arches over the rear axle when fitting a Panhard bar. 

     Does the Panhard bar really help?  Yes.  Is it truly worth the money?  My opinion is that it is a worthwhile addition to help control the rear axle location relative to the chassis or frame on the GMC P30 series.  I have driven one other P37 chassis motor home with a Panhard bar, and there is a difference in the handling in comparison with my Winnebago Elandan. 

     It just seems that it takes a lot of time to make all of these improvements fit together and work together as you are attaching a lot of different things onto your motor home.  It only compounds the felony when you are redesigning the conversion replacement systems to make them perform in a different way, or to just fit them all together under there in the space available. 

          Enjoy; 

          Ralph 
          Latte Land, Washington