My Chevy venture 2001 vibrates horribly under load. It vibrates at all rpm worse at different rpm, no rhyme or reason but again under load. changed plugs, wires rotated tires and checked for any noticeable problems. (Vacuum hose leaks, split wires etc.) Only thing I noticed was the transmission fluid was extremely high, I mean like ten times over the fill line. not sure if that could cause my prob or not? please if anyone can help? Money is tight and cant keep sinking $$$$ into this car.

 

Hi !
Check the front wheel bearings and CV joints (lubricant).
Also, look for signs of boots have leaked out all the fat. Pay attention to the installation of the motor. (See photo)