vibration help

[95BlkCobra]

ive got a vibration comming from the floor board of my car. it seems to be related to speed more than rpms. happens in and out of gear.ive tried rotating my driveshaft and checked my u-joints. i took it to a friend of mine who is a master tech and had him keep it all day to look at it. he says i have two bent rims and a slight vibe in the driveshaft. im thinking of just getting some new u joints and having the d/s balanced. my only concern is that it seems to viberate more with speed of the car rather than the rpms. like if im going 20 in 2nd at 2500rpm little to no vibe but if im going 65 in 5th at 2k rpm there is a vibration? im gonna pull my wheels tomorrow and balance them at work. if the two rims are bent where should i put them? front or rear of the car?

 

[Super Dragpack]

ive got a vibration comming from the floor board of my car. it seems to be related to speed more than rpms. happens in and out of gear.ive tried rotating my driveshaft and checked my u-joints. i took it to a friend of mine who is a master tech and had him keep it all day to look at it. he says i have two bent rims and a slight vibe in the driveshaft. im thinking of just getting some new u joints and having the d/s balanced. my only concern is that it seems to viberate more with speed of the car rather than the rpms. like if im going 20 in 2nd at 2500rpm little to no vibe but if im going 65 in 5th at 2k rpm there is a vibration? im gonna pull my wheels tomorrow and balance them at work. if the two rims are bent where should i put them? front or rear of the car?

The driveshaft and wheels are dependant on speed of the vehicle and NOT RPM's. He is most likely right.

The propshaft that comes out the rear of the gearbox, is spinning at whatever speed you are travelling, independent of what gear you have it in and even if the engine is switched off.

If you have bent rims, either see if someone can repair them or change them. There is NO sense in leaving them fitted as they will only cause more issues in time and could even be dangerous.

 

[CC'S95GT]

While you have the wheels on the balancer you can ck for run out too.
Just slowly spin the wheel and look for a wobble.
You can do this on the front of the car without removing the wheels too.

As said above get the bad ones replaced or repaired soon.