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After giving my GM-8 mount a service and freeing up bearings and re-greasing, I thought I would also give the even older G11 mount the same treatment which is permanently setup in an observatory (GM-8 is kept indoors when not in use). Dismantling most of it has been straightforward, but the two needle bearings in the RA axis don't rotate and need to be soaked in solvent to free them up. They certainly do not look rusty, so I think it is just hardened grease. I would like to remove the RA tube from the saddle and immerse it in solvent and at the same time dismantle the saddle to clean it and re-grease the threads and surfaces. I have undone a few of the bolts and screws but it looks as if I will have to resort to a mallet to tap off knobs and tap out the brass altitude pivot. Nothing just pulls out easily after undoing the bolt or grub screw. Has anyone done this before and able to offer advice?
Thanks.

Good day, I just did that this week-end with my G11. It is a 2000 model so yours might be a bit different. Strip everything then clean all the worms, gears, bearings with mineral turpentine and a brush in a large plastic tub to get rid of all the old grease. The bearings inside the RA and DEC housing you can just brush them until they get loose then keep rinsing them to get rid of all the gunk. Then let the whole thing dry. The day after grease all the bearings and the gears with a molypaste or equivalent (MP50 does the job). Be careful this grease is very messy. Whatever it touches is "wet". It will stick very well. That's the point anyway. Then you put everything back together and set the worm meshing then check the tension manually over the whole circumference back then forth. I usually do a service on the mount every 12 months. Once you've done it that many times it's just muscle memory.

I've nearly completed what I set out to do, which was to dismantle the altitude/azimuth mechanism. It did need cleaning. One of the needle bearings has started to free up after the RA axis has been in solvent for a day.

To dismantle, you first have to remove the grub screw from one the azimuth adjustment knobs. Then unscrew the knob (it doesn't pull off) and completely unscrew the threaded rod from the other end. You can then just lift out the brass block. On the underside of the equatorial mount is a single bolt holding a circular plate in place. Remove this and prise off the plate. Quite difficult if the grease is hard. You can then separate the top plate containing the spirit levels and RA axis. Again difficult because the grease was hard.

I wasn't able to remove the brass rod that the RA axis pivots about, but was able to clean up the altitude threaded rod with an old toothbrush and solvent. Most of the parts have now be degreased and ready for reassembly when the bearings are free.

When I started to take the RA axis apart, I did discover that I was missing a washer: Clutch knob, wavy washer, aluminium spacer, thrust bearing, washer …etc. There should have been another washer between the spacer and bearing. Will have to get another.