Last spring I installed a cam, precision industries converter, and stage II 4L60E all at the same time. Ever since then I've been chasing a beating vibration- like when two engines on a plane are out of phase / running at different RPM's.

After a new tailshaft bushing, rebalance driveshaft, new U-Joints, re-balance wheels, and going back to stock trans mount the vibration that used to be there on the highway is gone- BUT- I still have the vibration in every gear, and neutral between 1700-2500 RPM.

I spoke with someone yesterday that said the main bearings may be shot. He said he's seen LS1's where you could actually wiggle the crank by grabbing the balancer. Tonight I'm gonna go home and check it out. Any other ideas what could be causing this?

 

I just put the indicator on the crank (indicator base attached to motor) and with the indicator on the INSIDE of the balancer I could move it up and down .005". Is this normal?

 

did you have any problems installing the balancer?any rough play could throw it ouy of wack.just a thought.

 

Nope, used a puller to remove it. Used a longer bolt with a bearing under the head of the bolt to re-install- then put in the factory bolt.