Does "grating" on startout mean bad CV?
 

When starting out from a stop sign, more so when going left, it seems, than when going straight or right, I can feel a "grating" sensation when the car (89 951, w/137k) just starts to move, if I don't take it relatively easy on the pedals. It is definitely from the rear, and seems more likely the left side. Replacing the left wheel bearing may have improved it some, but it did not resolve the issue. I flushed/replaced the gear oil about 4k ago, but no record of any rear drivetrain maintenance/service before that, other than possibly a repack of the CV grease - I'll have to go though the papers again to know for sure.

At this point I'm thinking there is 1 or more worn (or bad) CV joints. Other than removing/replacing the splined bolts a few times, here-and-there, I have no experience with them. How do I check them? Also, do they need to be replaced if worn, or is there any kind of rebuild kit available that can "make them good again", if they are what is causing the issue? (or am I dreamin again?)