the procare people said that the vibration when i drive it up past 70mph is either the engine is out of balanced or the fly wheel doesnt fit properly, its a new flywheel, they know its not a tire balanceing problem.

My question is, is there anyway to do a test to figure out if its the motor or the flywheel? or something else? The passenger side seat vibrats as does the shifter ****.

 

Please help MEEEEEEEE!!!!!!!!!

 

Dude...I'm having the same problem(see my post below) It starts around 80 mph for me. I thought it was the driveshaft, so I put in a new one...it only helped slightly. This problem started after I had my new centerforce clutch put in, so maybe the idiot who did it messed up my flywheel too.

 

OK, I'm out of my league here, but if the flywheel was out of balance, would the vibrations be linked to the rpm of the engine, and not the speed of the car?
say your going 70 mph and you fell the vibration. Lets say your engine was at 2,500 rpms.

wouldn't you feel that same vibration if your car was in a lower gear and going 30 mph, if the engine was at 2,500 rpms?

Basically every time your enige is at x,xxx rpms you would feel that vibration if it was your fly wheel.
The flywheel spins at the rpm of the engine right?
Power goes through the trans, modified, and out to the drive shaft?
I think your vibration problem may still lie in your U-joints.

How bad is the vibration?

Don't take my post too seriously, my knowledge of flywheels and drivelines is limited, but I would think that it wouldn't do it just a 70 mph if it was flywheel related.

GOOD LUCK!

 

Oh yeah, Give us some more info. Make, model, year, and how many miles. Also, what parts have been replaced?
tires, bearings, trans mounts, etc.
that all can help people figure out just whats going on.

 

I have a 84 camaro Z28 with a rebuilt 350 which replaced the original 305. The guy that i bought it from said they had to replace the trannsmission with a heavy duty one and change out the flywheel with a larger one.

Your right it vibrates at 3500rpm in 1,2,3, and 4 gear, and it vibrates pretty badly at 70mph.

 

does it vibrate at idle?

does the transmission knock or anything?

my best guess would be on driveshaft, next would be bad clutch alignment..

 

what do you mean does it vibrate a ideal????? and what do you mean by trannsmission knocking????????

when i took it to procare they said that my driveshaft was fine and the U-joints were fine.

when i start it up in the morning it hovers around 2000rpm. When i slightly tap the gas it goes down to 800rpm. Is this what your talking about?????

 

first off, you haven't said what kind of transmission you have.

i'm assuming you have a stickshift since you just replaced the flywheel. automatics rarely break or warp a flywheel, whereas a stickshift will have flywheel problems..

if you have a knocking at idle it's probably the throwout bearing. and yes, it will give you a rough idle.. it did in my '68 Camaro..

the flywheel you're using may not be balanced correctly, generally it is but there's still a chance it's not..

when you have your driveshaft checked it did you have them see if it was out of line? (ie. bent) a bent driveshaft will give you problems like that on the freeway)

did you bend a rim?

you've still not said whether the problem is 'only' when driving, 'only' when idling (ie. car sitting at idle, in park, not moving), or all the time..

gotta be specific man, i can sit here giving hypotheticals forever..

 

it vibrates at 3500 RPM in 1,2,3, and 4 gear and when i hit seventy it starts to vibrate pretty badly.

The procare people said that they were sure it wasnt the driveshaft, they checked the U-joints and made sure it was straight.

Iam going to assume that the crankshaft needs balacing so do you know how much it would cost? is it expensive

 

you 'still' haven't said whether your car is a stick or an automatic!

no, the crankshaft would have nothing to do with it, that's an internal part and it either works or it's broken..

 

I forgot to say that it happenes all the time, on the road and when i ideal.

 

AND YES ITS A MANUAL!!!!!!!!!!!!

 

then like i said before, my best guess is on the flywheel being out of balance or clutch disc misadjustment

 

The other possibilty is the harmonic balancer.

 

It may be a warn out motor or trans mount.