The spring takes up the tension, and the manual recommends backing off 1/10th of a turn to prevent binding (yes, RTFM
)
.... it also says 1 and a half turns will totally disengage the worm...hence not sure where that 2 and a half turn suggestion came from
I'd also be checking lubrication, and double checking balance.
Also simply turning the mount off for a hour...letting things cool...and re-homing can work wonders.