60-65 mph vibe under load and dynamat

Decided to post this in a new thread. I know a lot of us have some degree of vibration/hum under throttle when cruising at 60-65. I personally have it very slight and think it is related to the vibration of the engine. I have noticed I feel it most in the pedal, as if I use cruise control and keep my feet off the pedal I don't notice it. So here is my thought, if I bought the a small piece of dynamat and put it on the firewall behind the pedal and insulation and then reinstalled the pedal would that dampen the vibration? Can dynamat be used for this? Should I line as much of the firewall behind the insulation as possible and then put it back together? I still wonder if this is not related in some way to the engine/trans mount. I have read where people have had almost every driveline component replaced but not the mounts..anyhow, thoughts on the dynamat? Will it dampen this type of vibes?

 

Have you tried making sure nothing is lose? I highly doubt this but even with my 4 banger there is some degree of vibration in everything. I think this might be the "its a truck not a car" deal. My vibes were pretty bad with stock tires until i got new ones and force balanced them. No more vibes. Take it back if you are unhappy.

I wouldn't recommend messing with the accelerator given its weak and plastic already. DO NOT put this on the metal where pedal mounts then screw the accelerator piece onto it. Adding sound insulation to the firewall might dampen engine noise a little but not much for vibrations given how stiff the firewall metal is.

 

I just replaced my driveshaft, problem solved. Totally. The damper inside the shaft was loose.