A Lionel 2016 has been setting in the round house for a year or more. Upon pulling it out, it would not cycle through the 3 positions without sticking. Took it to the shop and lubed the engine and hit the E unit with some cheap CRC CO Contact Cleaner. The E unit fingers and drum are in excellent condition. The cleaner seamed to fix the E unit operation while holding engine in my hand applying power from transformer.
Put it back on layout and still was sticking when cycling E unit. Took it back to the shop and got out good stuff, Caig Deoxit contact cleaner, the more expensive one I use to clean contacts on my vintage stereo receivers and the only one used by the folks at Audiokarma audio web site. One little squirt and that cleaned the E unit up fast and it operates like a new one. Deoxit will be the first one I use from now on.
Charlie