jazzz007

I have done a considerable upgrade on my drive line. At 1500rpms i pick up a vibration that pulses in and out of phase. It seems to go away as the rs increase and comes back in at 2500. then it is a violent vibration that could be causing damage to my drive line. I have changed convertors 3 times from a 3800stall tci super street fighter back to the stock and then another new 3800 super street fighter. It vids less with the stock but i figure it's because it is twice as heavy. changed the flexplate twice. No difference. From under the car i have checked the runnout on the flex plate and it is fine. It does it moving or in park. We went through the tranny during the upgrade and it is now a 4l65e with beast shell everything hardened and a set of Z pack disc with a kevlar band. Immediately after the upgrade i took her to the track and shattered the stock rear with a new set of 4.11 richmonds. right after that I noticed the vib. help me please. reward paid for the arrest and deportation of this vibration. by the way when the rear left it took the tranny with it and it had to be rebuilt also. where could it be coming from?????

MattZ28

iTrader: (4)

Pull the serpentine belt and see if it still does it. It could be a pulley.

1QUIKWS6

iTrader: (61)

And what pulley would that be? Only one that could cause that kind of vibration would be the crank damper/pulley combo - if you pull the belt it ain't gonna take that pulley out of the mix.

jazzz007

After 6 months I broke down and took it to the pro. Now we see what he comes up with.

Hugger

iTrader: (21)

I assume you have tried swapping driveshafts to see if that's it. Just a thought. Good luck finding it.

BubaGumpShrimp

iTrader: (1)

i just had a vibration that i could hear at 750rpms and then again at 2,000rpm. Wouldnt do it in any other rpm range. Turns out that when they installed my converter they never tightened the y-pipe mounting brackets all the way to the car so it would vibrate at certain rpms(750 and 2k). I thought it was my flexplate/new converter also. I happened to have the car jacked up to install a trans cooler and just for kicks i started banging on things like the y-pipe and i heard the vibration. Looked around for it and found the hanger bolt was finger tight. I thought no it cant be that simple. Well i tightend it up(put a nut on it too so it wont back out) and the vibration was gone... I suggest you go under the car with several wrenches and check all the bolts and on the trans too..

ps even if it doesnt fix the vibrations you may find a few bolts that are loose and could cause you other problems down the road..