What is a Torsion Rod?

Q:   I hear that the Elongator Tailgate has a Torsion rod in it. What is this and what does it do?

A:   Torsion bars have been it truck tailgates for some time. As tailgates have become heaver manufacturers have put these rods in their tailgates to make the gate feel lighter than it is.

Simply put, a torsion bar is a length of metal rod affixed on one side of the tailgate connection “hinge pin”. Usually about the diameter of a pencil or your finger. The rod acts like a spring. In the Elongator Tailgate this fixed pin is on the drivers side of the truck bed. When you mount the tailgate on the drivers side hinge pin what you are literally doing is attaching the torsion rod in the tailgate to the truck bed.

When you open the tailgate the fixed side of the torsion rod does not move. This causes the rod inside the tailgate to twist as the tailgate is lowered. As the tailgate is lowered, more and more “energy” is stored in the rod. The rod really wants to be returned back to the “unloaded” position. This causes the tailgate to lower more gently. In fact, during installation of an Elongator Tailgate before the ramps and folding extension are installed the open tailgate will “hang” in the open position around a 60 degree angle relative to the truck bed.

When you start to close the tailgate you are returning the torsion bar to its original location. In our case this is when the tailgate is almost closed. This is where it wants to go. This makes the tailgate feel lighter than it really is.

Many of the newer trucks have either torsion rods or “lifts assists”. Sometimes this is a small gas shock which is attached to one of the tailgate hinge pins. The shock is actually hidden behind one of the taillights. This is how Ford and Toyota do it. GMC/Chevy will have a small “damper” that is also located behind the passengers taillight.

The combination of a torsion rod AND a lift assist will make a tailgate even easier to open and close.