ninobrn99

iTrader: (8)

For example, when im in fourth gear and downshift to 3rd and am at about 3k and punch it, the car shakes really hard, the shifter rattles and the car doesnt accelerate strong at all. Could the be caused by anything internal? bearing in the motor, journals?? stuff like that? Im running the F13 112, stock ls2/ls6 heads, new lifters, new lifter trays, new timing chain, FMS 7.4" pushrods and PRC dual springs. none of which were broken. i got my cam in october of 05. Could any of that be it or is it an issue somewhere behind the motor? flywheel on back?

blue28

you've got something out of balance, that's for sure, could be a loose flywheel, balancer, clutch, driveshaft, rear gear, rearend mounts, lugnuts, or a burned piston or valve. just to name a few, if it's in the engine you'd be able to tell at idle though, if it's drivetrain(transmission included), it's only when your moving under a load, try slipping the clutch for a second it in the driveway. if it shakes with the engine loaded and the trannsmission stopped it's somewhere from the clutch and forward, if not it's clutch and back.

ninobrn99

iTrader: (8)

thanks. its tame at idle, only when driving it does it. lugs are tight, new clutch and fly was resurfaced recently and wasnt warped. since you mention the balancer, i may put the stocker back in to see if that helps. ive also had an issue with the car almost dying while making a hard turn and a few of us with UD pullies think it may be it.

gun5l1ng3r

Did you check the transmission mount? I have heard that when they are broken, they can cause the tranny to jump around under the car causing a 'vibration', this happens especially under load.

ninobrn99

iTrader: (8)

new mount

strokedls1

iTrader: (1)

I was think tranny mount as well. I know it's new, but have you checked it to make sure it is ok? That would give a good vibration. Exhaust touching the suspension will give you a nasty vibration. Check that all the lugs are tight. Check the balancer bolt. If none of those are suspect, maybe pull your plugs to see if any are damage from a piston breaking up. Usually an out of balance drive shaft will kick in under a certain rpm but can go away at other rpms. That was an issue I had before. Are the u joint bolts tight on the rearend?

ninobrn99

iTrader: (8)

Exhaust is resting on the tunnel brace, but the vibrations were never as bad as they are now. The tranny mount has been rechecked, I thought the balancer bolt was loose, but when i tried to torque it down, it hadnt budged. DS is new and PST did balance it. I know my pinion angle is off, but i dont think that alone could cause the vibrations im getting. Lugs are torqued to 110lb ft too..

strokedls1

iTrader: (1)

I got a bad vibration when my torque arm angle was to high up. I think it was loading the driveshaft u joint funny. I adjusted the rearend down to a -2 pinion angle and the vibration went away. Adjust that angle and let us know if it is still there.

ninobrn99

iTrader: (8)

will do. gotta have someone do it for me since im deployed. it sucks cause i like to do my own work and there's so much more to figure out with the car.