FLY WHEEL

[panchosteam]

I have a question about the fly wheel of the 6.5 and the 6.2. What will happen if i replace the one that came with my 6.5 engine for the one on the 6.2?. I'm thinking about doing this because i could feel some vibration and i don't know if is engine or transmission related,took the truck to a transmission shop to have them check it out and they could not find the vibration,took it to THE DIESEL TUNE could not find it either,i still think that it should not vibrate (my 6.2 used to run smoother on the freeway) could it be 6.5td engine not matching up 400 transmission or am i just picky? i had the belt driven vacuum conected to the regulator and i notice fast shifting,you could feel the shift like a bump,the other day switched it to the one that was on my 6.2 and it shifts smoother but, i still feel the vibration,this makes me tink about changing the fly wheel from my 6.2 engine,what do you guys think?
thank you
1984 GMC SIERRA CLASSIC PICK UP NOW WITH 6.5TD AND HEATH'S TURBO MASTER

[Turbo Al]

I would check the harmatic balancer at the front of the motor -- good chance it has gone bad.
Al

[C.K. Piquup]

We`re talkin` flex-plate here,not flywheel.I`d check harmonic balancer on front of engine.If this checks-out,could be bent/cracked flex-plate,torque-converter bolts,or problems with torque-converter.Is it a shudder,before upshift?When was trans back-flushed?