Vibration during acceleration

2002 Ford F350 Diesel 4x4 Automatic 250k miles

Recent there is a vibration which I feel as the driver and also from my passengers when I press on the accelerator. When I let off or do not press on the accelerator, the vibration goes away/stops.

I have had my U-joints checked (no problems or lose), carrier bearing on the drive shaft checked (was replaced 1-year ago), and tires balanced dna rotated 3x and not sure what next to check.

Occurs at all speed, but is really evident at lower rpm’s.

The fact that it’s most evident at lower RPMs, but happens at any speed, tells me it’s something with the engine rather than the drivetrain. Misfire perhaps?

I’m in agreement with budd2049. Seeing as how the truck has a quarter million miles on it and a diesel besides, maybe compression has dropped in a cylinder or there’s an injector issue, etc.

I has this problem with a diesel once. turns out an injector was bad.

Assuming there is no play at all in the drive shaft, from the xfer case to the rear diff.

Good comments above. Check those. Also check the motor mounts for excessive wear.

It’s also possible this is a problem in the rear differential. First thing, make sure the rear diff fluid level is ok.