Okay, got a frame question for you suspension guru's.

I have a brand new 2006 1/2 ton RAM and was under the body last week installing my nerf bars and a trailer hitch when I noticed a couple of odd looking differences from my 2004.

First, on the frame under where the trailing edge of the front doors meet the leading edge of the aft doors there’s a couple of what appears to be harmonic balancers bolted onto the frame. This is on both the left and right side of the truck frame. (Looks sort of like a dumbbell).

Am I right? Is this a balancer to absorb vibrations? The reason I’m asking is because we use the same thing in aviation on the engine mounts of commercial aircraft. In particular the MD-80s forward upper and lower mounts for the P/W JT8D-217d engines.

Second question, when hooking up the trailer hitch I noticed what appeared to be some sort of torsion bar tucked-up in the upper frame located in front of the rear license plate as viewed from below looking up.

You can grab a hold of this bar, (it’s about 12 to 18 inches long and approximately 2 to 3 inches in diameter), and turn it but it’s spring loaded to return to it’s original position. At first I thought it might be a tail gate assist but upon further examination it looks like it something to do with the trailer hitch frame?

Any ideas?

H.H.

 

Just talked to a buddy here at work and went out and showed him what these things are on the frame. He agrees they look like vibration absorbers. He also thinks the Torque tube could be something along the same lines.

I'm going to stop by the dealership tomorrow and verify this. I'll let 'all know what I find out.

H.H. ~working the graveyard shift~

 

Yes, they are harmonic balancers. The application here is to reduce what is called beaming. Expansion joints in US highways are at a fixed interval. As the truck/trailer combo hits these expansion joints at a constant rate you develop a simple up down harmonic motion. At some point this becomes annoying more than fun. To reduce this condition your vehicle has harmonic balancers on the frame rails, and back by the trailer tow on select models.