Symptoms: vibrations in the accelerator pedal and floor board as well as a sound (almost like an exhaust leak sound). So far I have put the car on jacks and put it in neutral, reved up the engine no vibrations, put it in gear and reved it up to 60mph with the back wheels spinning and the whole car shakes. I have 4 new tires balanced so it is not that. The sputter and vibration only happen when I press the accelerator, if I go down hill without giving it any gas everything is cool so it couldn't be the driveshaft, what is left to check?

Thanks for any input cause I am don't know what to do.

Jerry Atlanta

 

rubber disc coupling.

 

Thanks Sleepwalker

So if it take out the drive shaft, replace the flex disks and the center bearing do I have to get it rebalanced?

 

And also sleepwalker, what is the purpose and how does the kickdown switch on the transmission work? I read you post on testing it but I am still a little confused. Do you know of a good manual for transmissions that I could find on the net?

Thanks

 

just mark the spline and return it on the same position. balancing not necessary.
if in doubt, lift the car and put it on gear. using a piece of chalk, check for any offset. if too big, then it needs more attention.

regardless of any gear while you are during driving, it actuates the kickdown solenoid which opens the regulating valve inside the valve body.
since you will be pushing the accelerator pedal further down, the command valve also opens wide since the control pressure cable pushes it.

it is difficult for me to explain but the kickdown control pressure is formed in the kickdown system. this pressure acts on the governor pressure and thus determines the kickdown shift points.

i believe the springs inside the valve body are the ones that determines the shift points...in accordance of course with the governor pressure on normal driving.

only by fully understanding of how these fluid pressures combined by mechanical (and a bit of electrical) functions that we can easily detect the problems.

10 years ago i was very good at these transmissions that i can disassemble and assemble them blindfolded. a car would come with transmission defect, and after hearing the complaints or driving it a few meters...i know exactly what to do.