Hi folks.
My 52 3/4 ton GMC pick up will run down the highway at up to about 3500 rpm (as much as I dare). It's got a 235 straight 6 made a few years AFTER this truck was built, but it does well.
My question is concerning a bad vibration that really prevents me from wanting to go faster than 65, even though physically I can. I just avoid it because of the vibration.
I started out thinking the 235 may not be a very well balanced type of motor, but that theory went out the window when I stepped on the clutch at 70 mph and watched the rpms drop to 1000. The vibration is definitely speed-related and not engine-related. This caused me even more concern.
It almost felt like it could be coming from the front wheel bearings. What are the thoughts from some of you more experienced Stovebolt owners? What would be a good way of isolating and fixing the vibration...or is beyond 65 mph the design limit before these things shake themselves apart?
Thanks...
