Originally Posted by
Caseymacgyver
Chatter is not a fact of life. It's true that all single joint CVD's will exhibit velocity and torque variation while rotating whenever there is an angle between the input and output shafts.
I feel the the problem is not so much in the torque variation (probably greasing the cvs with the right stuff and not trying to get to full angle helps here), but in the velocity variation. Wheels off, there is no chatter at all because there is almost no weight after the joint. Wheels on, you are hit by the wheel mass - it has enough inertia to induce nasty chatter because at each wheel revolution the cvd has two complete cycles of velocity variation, to which the wheel opposes.
Normally while driving you will likely not notice much chatter because of the ambient noise (also on carpet it dampens the noise).
The chatter is particularly nasty with front spool, wheels fight each other being directly coupled. It's better with ball diff which can absorb some of the vibration and best with one way which allows any wheel to rotate faster without dragging the other one either way.
What I don't get is that almost everyone will tell you there should be no chatter, denying the simple fact that a simple cardan joint induces velocity variations when angled.
OTOH seems problem went noticed when onroad racers started to look at front spools, wanting to keep traction on both wheels while cornering. Therefore we now have those (very few) DCJ or ECJ as they are named. Think I read that latest tamiya ta chassis will come stock with such axles.