black05

hey guys, im wrapping up my project car and for some reason im just noticing now that if the car is running and it does not matter if im driving or not, that when i rev the car past 3000 rpms, the car shakes bad and you can feel it bad in the shifter. the higher the rpm, the worse the shake. my assumption is that if the car vibrates like that out of gear at a stop than the motor mounts are bad or the harmonic balancer is bad. my car is an 85 gt with a 306, trick flow heads, victor jr. intake, holley carb ect. it dynoed at 285 so nothing crazy but i dont know what it is and i dont want to drive it like that cause if its out of balance i know i can ruin other things. were should i start. thanks, john

stang8689

driveshaft could be out of balance, I would get an aluminum one, also polyurethane trans mount really help on the vibration of the shifter ****, I would also get polyurethane motor mounts

Bullitt94

Since is vibrates when out of gear (I assume that's what you mean by when you are not driving) you can rule out u-joints, dirve shaft, tranny, etc. I'd check motor mounts and harmonic balancer first. Good luck.

mattdel

both of you just said what he already said. wtf. read.

look on the back of the balancer for the rubber ring going around it. it shouldn't be cracked or broken/missing or protruding out much more than 1/16th of an inch.

black05

i was told that i should pull the tranny to see if i have wobble in my input shaft on my tranny but i dont think that would cause the vibration when at a stop and out of gear. i can be in nuetral, no clutch in rev it up and it will vibrate through the tranny in the shifter **** real bad its very excessive. you can fell the vibration start at idle and it gets worse the higher the rpm's. what ounce balancer and which one should i get. im on a tight budget but i dont want cheap stuff on the car. thanks a lot, john

black05

i have an aluminum driveshaft and i will check the motor mounts asap.

ddeaton66

^^^ Ditto I would check the harmonic balancer

WhiteWindsor

The mounts are not causing that kind of vibration, do what he said above.

black05

i might as well just replace the balancer to eliminate that from being it. were should i buy a new one and what one do i get? also, i do not know if my rotating assembly was balanced internally or not cause i bought the car with the motor done. so how would i know? what balancer do i get the 28 ounce or the 50?