I have an 88 300 4spdw/OD(ZF) tranny. I've never had a clutch go bad so I don't know if the clutch is slipping or if I'm running rich and its cutting out. Another problem is that there is driveline vibration- it doesn't appear to be the u-joint it seems to have movement on the pinion shaft-Bearing out? Greatful for any suggestions.

 

Describe the hesitation. Does the engine RPMs go up to accelerate, then seem to die or a flat spot, then fine again? Or is the engine RPMs fine and the truck itself doesn't seem to keep up with the engine?

If its the latter, look at the drivetrain (clutch, clutch cylinder since you have a ZF, etc).

If its the former, check the cap and rotor, fuel filter, air filter, plug wires, all the regular tune up stuff, and if that doesn't solve the problem look at things like the map sensor and IAC motor.

 

I guess I should have described it better. It actually will kind of kick and buck even on flat ground if you try and give it gas quickly. I've replaced the plugs, ignition module, the cap and wires look like they are in relatively good shape. It kind of seems like the later. She idles fine except at startup it lopes for a couple of seconds and then levels out fine? Is the ZF a good tranny or not? I know the pinion bearing is worn there is some driveline vibration especially when coasting. I thought it was the u-joint at first, but when I got under and pushed on the shaft it ws moving at the pinion in the housing. Appreciated your response and any help would be appreciated. Is the pinion bearing a drive way mechanic fix or should I take it somewhere?