Thump Thump On Shut Down?

[powerplant]

Ok A week or so i did the tymar nice mod put new shocks on. But now ive developed a noise on shut down as soon as the motor stops i get this dull thump thump it seems like its coming from behind dash you can almost fill it in the steering wheel. Had the hood up early tonight and tryed shut down motor doesnt seem to be doing anything weird any ideas i tryed looking in past threads nothing like it Thanks

[bigcountrysg]

Maybe a vaccuum leak. The vaccuum pump loosing vaccuum causing the noise.

[powerplant]

On shut down its a real weird thump almost like you can feel it could it be motor mounts lose . What would the vac do with that i know it controls the vent door but this is coming from the steering column dash behind instrument cluster area

[99bigred]

you sure its not the flywheel or clutch slowing down? ours kinda makes a thump or deep rattle noise and shakes the truck a little but i think it did that since it was new
other then that maybe motor mounts but dont really know
good luck

[powerplant]

Your guess is as good as mine Wouldnt you feel that all over the truck. Dont under stand Why thes trucks have so many gremlins That what i feel like doing to it sometimes

[powerplant]

one time Thanks

[powerplant]

Any more ideas

[99bigred]

yes your right the clutch thing i talked about i do feel through the whole truck.
out of ideas but heres a

[powerplant]

Could be the fly wheel never did do it till a week or so or you could never here or fill it Could it be the flex plate coming apart

[powerplant]

Ok its not behind the dash its somthing Knocking the floor board area. Any ideas could it be cab mounts im going to investagate this week end. Any ideas were to start thanks