My cars coming out of storeage here on monday and just want to know what i should start looking at. I didn't want to deal with it prior to storeage and now its time to come out. Its a 402 with a rpm stage 5 4l60e A4 ok so heres the issue. Over the past 3 weeks i had it out before storage time the car produced a noticeable vibration coming from the rear at about 4000-5000 RPM. The whole car shakes. Doesnt matter what gear. Anything below it it doesnt do it. And WOT it doesn't do it. Just curious to know where i should start looking when i take out monday. I took a few master techs for a ride before storing and noone could pinpoint it by just riding in it. No other noises associated with normal driving just an obnoxious shaking during heavy accel. Just not normal driving or WOT the cars about 560whp so i could just not be noticing it at WOT. But just curious to any ideas on what it could be. Car doesnt appear to lose any power during this period of shaking or start dragging or anything. Just shaking. I have no clue what it could be. I installed a SFI FLEXPLATE and a B&m ratchet shifter along with a starter at the beggining of the season but if that was an issue the 4,000 ago i installed it i imagined it would of showed its face. Car is babied and not tracked or launched. And not really even beat on never floor the car under 40mph. Any suggestions help

 

It almost feels like wheel hop... but the car does this vibration everytime i want it too.. and its not wheel hop.

 

Does it do this in neutral sitting still, or going down the road? If going down the road, I'd check tires for balance or bad belts, then half shafts or shocks.

 

So it's RPM related regardless of which gear its in or road speed? I had a similar issue, was the torque converter messing up..... I tried a cheap trick to test it: disconnected the TC bolts and rotated it 1 set of holes and the vibration changed considerably so I then removed the TC and sent it out for re-stall and balancing and it solved the problem....then after that, next season I had to replace the prop shaft bearings in the torque tube to cure a minor vibration.....

 

ive only been able to get it to do it between 50-75 ive never been able to test lower speed or higher speed. 5000rpm at 3rd is about 140mph and trying to get to that rpm in 1st you cant control the car... so i guess ive only been able to do it in 2nd. I just had a new tq converter installed via RPM transmissions 2 years ago. One comon issue when i got the car 3 years ago when i give the car i nice rpm rise in park when the car comes down to idol speed it kind of trips over itself rpms pulsate trying to recover but i just imagned that was nature of the beast with a 700 horse automatic.

 

Mine would even do it in neutral at the corresponding RPM as the road speed, pointed me to the TC as its always spinning, you got some diggin to do..... I hate vibration related issues, but they seem to eventually pop up at about 250 hp over stock..sooner or later...

 

so throw it in neutral rev it up to 4000 and if the shaking starts. Thats the culperate is what your saying?

 

Have you checked the drive shaft couplers and bearings?

 

1 cracked from wheel in the front and 2 bent and warped rims in the rear is/was the culprit.... time for a drag pack!!!!!!