Sometimes while slowing down i can hear these clunking noises from under the car. Sounds like something banging on the bottom. The other day I was driving it and it did it while accelerating in 1st through 3rd. I thought that my tranny mount was gone so i replaced it. Didn't look to bad, but changed it anyway. Shifts are smoother and the clutch seems to grab harder.
Anyway, the noise is still there but faint (so far) Could bad u-joints make that noise? sounds like it would be the driveshaft. What would I look for on the u-joints for wear? cracks, bends, what?? How hard of a job is it to replace them? Never even touched them before, so what range would a shop charge to replace them?

 

Not sure what it is, but I would like to find out as mine started making the same noises a week ago.