Bret

I'm not exactly sure what the runout is on the drive shaft, but none is visible to the eye. The drive shaft specialist that I took the car to said that everything is within specifications, so I'm pretty confident that the drive shaft is not the problem.

Utah S2K

Look for a dislodged tire weight. Temperature changes due some strange stuff to adhesives.

KIDS2000

Hi Sheister...
Can i see a pic of your car?
im interested to see if it looks like Silvias/200SX that are meant for the asian and australasian markets...
Im a big fan of the Silvia series! Cheers!
send to vivisect@hotmail.com

Bret

I'm still on my eternal quest to find out what is causing the vibration in my 240SX. Last night I took off the wheels/tires and put them on my new Altima. I was lucky that they are the same size. The Altima drove fine without any vibrations at all. I then put the Altima wheels/tires on the 240SX. The 240SX still vibrated the same, so now I can definitely eliminate the wheels/tires as the source of the problem. This leaves the differencial and half shafts as the potential source. Does anyone have a suggestion on how I might test these?

Big Al

The runout you mention seems excessive, but I would check the specs in a factory manual.

The fact that it vibrates more with the mass of the wheels on the car indicates worn wheel bearings to me. ( Vibration amplitude and frequency are affected by mass.) With the car off the ground can you detect any sloppiness in the bearings? However even if you can't, it doesn't mean the bearings are OK. Not being familiar with the Nissan, I assume you can't visually check the bearings since they're most likely sealed.

I had a similar problem with a front drive German car and it was a wheel bearing on one side. BTW, I could not detect any sloppiness in the bearing by feel.