Eric, having just brought a 5400 elevation rotator back into service I would say you should do the following.
Open it up, add anti seize compound to all the nuts and screws. Replace both sets of ball bearings with stainless steel ones. I was advised they are 5/16" not 8MM and have had no issues with imperial sized ones, I chose to leave the bearing retainers in place. Regrease everything and wipe all the cog surfaces with grease, the one on my position pot was badly corroded. Junk the eight cross head bolts that hold the casing together and replace with stainless socket head bolts. Use a liquid gasket when you stick the two halves back together and consider enlarging the drain hole in the case. This may seem a lot of work for something that is effectively new but it will save a lot more grief in the long run.
The azimuth rotators seem to fare a little better but again I would replace any external bolts with stainless, ditto the bearings and regrease/anti seize everything else.
It's a convenient time to say thanks to everyone who offered advice and tips when I renovated mine. As I took some photos through the process I decided to put them together in a small web page, hope it's OK to post it. http://www.ukdx.org.uk/tv/rotator.htm
73 Paul
On 03/07/2018 23:31, Eric Garner wrote:
I acquired a G5400 az/el rotator that looks to be in pristine condition, apart from some rubber rot. I don't think it's ever been mounted outside in the weather. Since this has been in storage for probably at least 20 years, what should be done with it to put it into service? does it need to be pulled apart and re-greased? can I just replace the rotted rubber parts and call it good?
pictures here:
http://www.pushingbubbles.com/radio-stuff/new-rotator/
thanks
-Eric KI7LTT