i was test driving an fc today, and starting at about 15mph the car started to vibrate pretty bad. it felt like it was coming from the rear of the car, and my first thought was either cv joints, or the wheel bearings. has anyone had this happen in their car? i need to know the problem, because this could be the deciding factor if i'm going to buy this car.

 

i would say really bad u-joints
do you hear any weard noises like clunking?

 

no clunking or anything like that, just a vibration that shook the whole car (it kinda felt good on my back, lol).

 

is it an S4 or S5?

 

s4, 5sp, 5lug, and i'm not sure of the year. 145k miles. there are no badges on it besides "mazda" and "rx-7" so i don't know if its a gxl, or gtu or what have ya.

 

you do anything with the tranny latley, like take it off?

 

Ok two possibilitys 1, your rear tranny mount has given up the ghost. Usually unlikely unless you have been flogging the car. 2, you have a bad U-joint either front or rear. THis condtion may or may not clunk when wiggling the U-joints. As in my case the rear U-joint just simply froze up.

Used replacements are easy to get, or you can get a rebuilt driveshaft for about 120-180.