Hi Craig,
These extra thrust bearings are probably from someone who had installed encoders but removed them before selling the mount sometime in the past. The new owners did not know any better and just left them on. My advice is to order a set (2 pieces in the kit) of new thick black aluminum spacers to replace these early version small-diameter spacers which appear to have a lot of wear. I also highly recommend new thrust bearings and the matching thrust bearing races (what are referred to as washers but they are actually precision parallel flat ground races) as well as an HP worm for the RA axis. You will want this for imaging even if you keep the #492 Digital Drive for imaging. For modest focal length optics, the Digital Drive works well and can even be guided. The HP worm on the RA axis should improve your unguided and guided imaging results significantly assuring you get it well set up and adjusted. Google Michel Herman and Bellevue spring disc modification for Losmandy mounts.?
I upgraded my old G11 to the latest G11G specs twice and for me, it was worth the cost because it was my trusty old friend. I was also going to do the same for my GM8 Gemini 1 but Covid got in the way and after waiting a year I gave up and ordered a new GM8G and sold my old GM8. The new GM8G is a great mount and I have added 311K encoders and a Nexus DSC for visual use working the mount manually as a PUSH-TO mount which the Losmandy mounts were designed to be used as long before computers and Gemini was available.?For a used mount with little personal history, it may be more cost-effective to buy a new mount if you really want the latest version with all the features like tucked servo motors and sprung OPWs as well as the latest Gemini 2 controller and firmware.?
But if your vintage GM8 is in good shape and not faded it is IME well worth upgrading as they were made as well or better than current production mounts once updated. Plus this mean you can clean it up and enjoy it and upgrade as needed.??
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Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
Chip Louie