Quote Originally Posted by Doug44 View Post
Personally (you did ask for others opinions) I wouldn't sweat it. I have seen at least one other person on this forum say it will ruin your rear end etc I hope he isn't correct ! One saving grace is if it goes bad there are several who have bought new trike take offs for around $100 for the complete Assy. Again personally I would fill it with Mobil 1 synthetic 75w90 grade I think it is and not worry. Perhaps also if your dealer contacts Honda maybe they have this special juice they put in at the factory fill. Just this past month a friend I ride with took his GL1800 in for a rear tire and his GL had 11k on it and he ask them to check his oil level and they like your dealer said "it was nasty looking so we drained it and refilled" IMHO I can't believe that draining the rear end premature will result in complete rear end failure.
Changing early while usually not needed as it is a closed system wont hurt a damn thing! The reason the oil gets black is not MOLY that everyone thinks Honda specifically puts in but rather a phosphate coating that is on both the ring and pinion during the manufacturing process.
The phosphate coating is an anti corrosive as well as a help in the lapping process. Once the ring and pinion are lapped they are a matched set via contact. It wont hurt anything being in there, and also wont hurt to pull it out and replace the lube either.