I want to remove all of the old grease from the front wheel gear unit and replace it with new grease, but I don't want to damage it as it is nearly $100 from yamaha. how should I go about cleaning it out? Thanks.
Yup did the same to mine recently, annoying that a clever Yamaha design engineer made the washer sacrificial but a bean counter decided you cannot buy one. However Steve has them .
Mine gave up, had a spare one that came with a wheel and that gave up. Modified one slightly with extra washer to compensate for wear but eventually that gave up. At that point I gave up and now run the housing and dust seal only, replaced all the gears, cable and clocks with a pedal bike speedo that cost about £3 from China, weighs almost nothing, senses a magnet fixed to 2 spokes with shoo goo, doesn't sap any engine power, gives me a load of info the old speedo didn't (clock and swap to kms being most useful) and seems completely reliable! The cable from the sensor strapped to the fork leg comes up a bit of tubing fixed the same way as the cable used to be so the fork action doesn't break it. 3 idiot lights replaced by IP65 LEDs also from China for maybe a pound each...
Planning to do a full picture descriptive of this mod at some point, maybe when I get my flash new nose fairing on!