when i let the clutch out a little and put it in quickly, there is a thumping that comes from under the car.

i put the clutch in while im rolling 15 20 mph move the gearshift back and forth between 1st and 2nd and there is more thumping.

im thinking its the drive shaft. if it is, can i get universals for an 89, or do i have to get the whole shaft?

 

The stock driveshafts don't have replaceable u-joints, but Mazdatrix sells one that does. There's a guy in the 2nd gen forum at http://www.rx7forum.com who found a set of u-joints that can work with a stock driveshaft. Try checking there.

 

You have to do the whole shaft, but I've heard of places that will take out the U-joint and put a replaceable one in. Mazdatrix also sells new shafts with a replaceable U-joint, as I remember.

 

What the of course you can just replace the uni ,any half assed driveline shop can do this with minimal machining just make sure they balance it properly ,ive had mine done with a holden uni and absolutely no problems here and its been driven very hard , see dont believe the hype.