For a while now I've been having this clunking/bucking from the rear end of my 1993 RX7 Fd. The clunking only appears in the lower gears, mostly 1st gear. The clunking only happens if i don't balance the clutch correctly. When i balance the clutch there is no clunking. I want to figure out whats wrong so I can fix it. My best guess is i need to replace the pillow ball bushings in the rear. Any suggestions? or how to check?

 

Pillow ball bushings are kind of a consumable on our cars. The rubber seals get loose, moisture and dirt get in and just a little 'slop' in one or two can be magnified by the car to sound like Jimmy Hoffa's trying to escape out your hatch. That said, if you're hearing noises from a stop as you've described, I may FIRST check the differential bushings. They're up high on the rear crossmember. They're oil filled and can leak. So evidence of fluid on them is a pretty good sign.

 

The clunking is only when I start to accelerate from 1st or 2nd ,, not when I'm at a stop. I haven't experienced any leaks at all.

 

OK, but what you've described is related to the drivetrain and particularly when it's under load. That would point toward things along that drivetrain. You said it was in the back, that would suggest to me the differential bushings.
If it were the suspension's pillowball bushings they would clunk over a bump in 4th gear just as they would between 1st and 2nd. And diff bushings are fluid filled. That means a few cc's of fluid in each, not necessarily something that's going to show up on the garage floor. Jack the car up, put it on stands and look, shake and see what you can find.