Bob,
If your mount is only two years old the gearbox lube is probably fine because the gears and lube are all sealed up in a nice closed clean environment that operates at a very low load and speed. The gearboxes can add very little drag to the stepper motors and there is no good way to re-lube them without drilling out the plastic or probably in your case, steel rivets to disassemble them and re-lube. You can check the gearboxes once disassembled by turning the gearbox output shaft by hand, there is always going to be some drag and probably a spot where it wants to slow down a little bit but that additional resistance is unimportant as you are working the gearbox backwards and the stepper does not see this resistance. Remember that the gear box is a 25:1 ratio so as long as there is no gritty feeling while turning you are good to go.?
One other thing, I'm assuming your GM8 came equipped with the Losmandy HP worms installed but that you do not have a one piece worm block installed on the RA axis. The reason I say this is that either of the OPW designs improves or resolves at least four of the five drivetrain design issues which significantly affect the tracking error numbers of Losmandy G11 and GM8 mount drivetrains.?
#1 Worm bearing alignment
#2 Worm bearing preload?
#3 Worm mesh adjustability?
#4 Alignment of gearbox output shaft axis to worm gear axis
#5 Gear mesh adjustment?
Hope this helps.
Chip
