When I shut the engine down, there is a loud klunk sound and the whole truck shakes once. The severity of this symptom varies quite a lot. It obviously has something to do with the engine quickly going from a state of turning to a state of not turning, but.... is it something I need to worry about? Is it normal?

Thanks,
CR

 

Normal... The belt chirp and shake is a common thing on the first gens

 

The klunk makes it sound like loose motor and/or trans mount. The shake is normal.

 

...and if you had a broken mount, would seem worse than it is

 

JD and CS are right on, it sounds like a loose or broken motor mount. Tighten everything before you go throwing parts at it, the Cummins will shake pretty much everything on the truck loose at some point.

 

Even overdrive solenoids .
And i do believe the good Pastor put it best by calling the old "wet dog" shake