I am noticing a rumble I can feel upon acceleration. I can feel it in the steering wheel mostly . I thought it may be the fan clutch because I felt some axial free play. I change hit but still feel a rumble. When I back off the accelerator it stops. Accelerate and I feel it again. Any clues? Hope it's not the trany. Misfiring injector? No noticeable smoke and it's a naked 91.5 D250.
​​​​​​​Thanks

 

Have you checked the motor mounts?

 

A bad u-joint can do that as well.

 

 

I've checked the motor mounts and I don't see the engine doing any odd twists or tilting. My u joints seem tight enough,when I twist and jar the drive shaft. But it is old and hasn't been any trouble so I don't mind replacing a few things.
One odd thing though is when I bled the injectors some of the splled fuel dribbled down the injector and I noticed bubbles escaping from the injector seat so I also have those on order. Maybe u joints today and continue chasing the rumble. Thanks guys!

 

U joints it was! Spicer #5-160X and SKF 16725 oil seal and good to go.
Thanks,
Lou