Bad vibration in neutral

I just got my 67 CJ5 this pass weekend, and now finding out about with the engine swap.

I get a bad engine vibration, if I mash the gas pedal when the trans is in neutral with the clutch out.

It doesn't vibrate at at all at a idle or if the trans is in gear if you give alittle gas, and it doesn't vibate when driving.:driving:

Would it explain the bad vibration if the 225 flywheel was used with the 231? Or is something else causing it?

Has anyone run into this problem before?

UncleSam

 

An odd-fire V6 has a rough idle compared to even-fire engines. Buick used soft motor mounts to address this. But that's just a little shake - not very noticable, other than it's different from your typical "is it still running?" smooth-at-idle inline 6.

The odd fire also has a different flywheel balance from the even fire 231. The flywheel would need to be rebalanced, if a 231 even-fire were swapped in to replace a 225.

 

No it doesn't vibrate with the clutch in. Just with the clutch out and in neutral....but it doesn't do it at an idle, just when I rev it up. But when it's in gear it won't do it at all. :?

That make sense..

It drives good, trans shift smooth.

Thanks for the thought...

 

Could it be loose flywheel bolts? With the clutch in, that pushes the P/P forward which pushes the f/wheel forward holding it somewhat tight but that doesn't relate to driving down the road with clutch out? Sure scratching my head unless it is as Tim is suggesting.

 

Bad pilot bearing.

Bad clutch disk.

Bellhousing bolts loose.

Trans bolts loose.

 

I vote for bad or missing pilot bushing.

 

harmonic balancer?