MI-250 GO-TO
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This page is courtesy of Daniel Maloney
Re-greasing the RA Worm and Worm Gear on your MI-250 Non-GoTo
(without removing the worm or worm gear)
Preparation
Q-TipsEye Shadow ApplicatorCitrus Degrease\Mineral SpiritsBlack MolyArtist Brushes
You will need a few items to finish the task of re-greasing your RA worm and worm gear on the MI-250:
  1. 1 Box of Q-Tips (you will have some left over but you will use many)
  2. 10 packs of Eye Shadow applicators (these will be used to clean old grease up from the worm and worm gear teeth).
  3. 1 bottle of citrus de-greaser or 1 can of low odor mineral spirits (preferred).
  4. 1 can of Jet-Lube Black Moly Paste which can be found here.
  5. 1 pack of artist brushes found at your local Lowes or Home Depot.
Step 1
MI-250
Make sure you setup your MI-250 on a level surface and get a comfortable chair because your going to sit in it for awhile.  Proceed to remove the front cover of your MI-250.  There a four button head allen screws and one small phillips head screw to remove.  Be careful when lifting the cover off as there is a RJ-11 cable connected to the HC\CCD jack which you can unplug once the cover is lifted off.  There is also the 9V battery terminal that you weave under the RA motor as you are pulling off the cover.  Just go slow and look behind the cover as you are lifting it up and you will be fine.
Step 2
MI-250
Once you have the cover off your mount should look like this.  You may already notice the old white lithium grease packed on my worm.
MI-250
Here is a closeup of my RA worm and worm gear, you can clearly see for once there is way to much grease on the worm and that the grease is dirty.  Some has even dropped onto the worm mounting block.
MI-250
In this photo you can see where the white lithium has hardened on the front of the RA worm gear and that there is way to much grease in the teeth of th e worm gear as well.
Step 3
MI-250
Set your cover to the side of the MI-250 and plug back in the HC\CCD cable and your 9V or 12V power as you normally would.  Do not turn it on just yet.
Step 4
MI-250
Proceed to clean off as much grease as you can using your Q-Tips (dry) which are used to clean excess grease on the worm and worm gear front and back.  When cleaning up excess grease from the back of the RA gear you will need to bend the Q-tip to get it behind the RA gear.  Just make sure after you bent it that it is not broken as you do not want a rouge Q-tip head falling being the RA gear.  Use your eye shadow applicators (dry) in the worm and worm gear teeth to clean the grease up from them.

You do not need to exert much force at all to cleanup the grease so be gentle.  When using either the Q-tips or applicators I would use them for at most 2-3 swipes and then they were thrown away.  Always go over areas 2-3 times (especially on the rear of the RA worm gear) to be sure you removed all remaining grease.
MI-250
There will be old grease that you cannot remove without moving the worm and worm gear.  As you know the MI-250 Non-GoTo really has only one fast slew (16x) and it really is not that fast.  Here you will see I used two crescent wrenches to keep the fast slew engaged.  I just turned on the mount to move the worm gear enough to clean the grease.  It may take 10-15 minutes with several iterations to move the worm gear enough to clean those tough areas.  Patience is required.

Important: Once you cleaned up all visible old grease, go over those areas with Q-tips or eye shadow applicators dabbed (not soaked!) in citrus de-greaser or mineral spirits (preferred).  This will clean the surface of any remaining impurities.
MI-250
After 1-2 hours of cleaning your worm and worm gear will start to look like this!  You will notice I have a bit more grease to remove from the worm gear's teeth.  Almost there!
MI-250
All done!  You can see the striking difference from this closeup of the worm from the pre-cleaning photo at the beginning.
MI-250
No more hardened white lithium on the face of the worm gear either.
MI-250
While you are in here, take some extra time to cleanup any dust and dirt on your RA motor, its mounting hardware, and electronics. 
MI-250
You will have a disposal bag of Q-tips like this after finishing.  You will notice cotton pads, I used those just to clean the inside of the MI-250's housing.
Step 5
MI-250
Now with everything clean and the mount turned off use a medium tip artist brush to brush on the Jet-Lube black moly grease on the worm and worm gear teeth.  A small amount of black moly goes a long way and there is no need to lap a ton of grease on the worm or worm gear teeth.  Just use enough to lightly coat the surface, that is all that is needed.

Again you will need to power on the mount and advance the worm and worm gear to reach the tough locations.  You will also want to advance the worm gear at least one full revolution to distribute the new grease.  This will take 1-2 hours to complete even at 16x slew rate.  As it is advancing periodically check to worm to ensure there the grease on it has not become to thin or unevenly distrubuted.
MI-250
Here is a shot of the worm gear teeth just so you can get an idea of how little black moly is needed.  Once your full revolution is complete you can re-attach the front cover and enjoy your newly re-greased MI-250!