With the clutches engaged, if you can wiggle the RA axis or Dec axis when holding the CW shaft or diagonal then you have backlash between the worm gears and ring gears.
This guide for the EQ6 (AZEQ6 is similar) shows how to adjust the clearance between the worm gears and ring gear (section 5). There are 4 bolts to loosen, then adjust 2 grub screws to move the worm closer to or farther from the shaft, then re-tighten the 4 bolts - very important not to overtighten the worm clearance and cause binding, but you can adjust the clearance such that a tiny gap is left which fills with grease when the motor turns, effectively leaving no backlash, assuming the ring gear/shaft is perfectly round.
https://web.archive.org/web/20160503...own%20Home.htm