Everybody seem to think that a nexus 3 speed is really hard to work on. There could be nothing farther from the truth. I have recently had a few/bunch of used three speeds come into my possesion. I had some that the axle is messed up on where they were nonusable in their present state...so I figured hey I didnt pay anything for them so ill tear them apart. I was like many of yall thinking man look at all the gears and stuff in there. It all goes together one way ...no surprises. Nothing jumps out or goes flying apart when you dissasemble them. You take the sprocket off with a round c ring and then on the side where the brake arm is you take off the two nuts. I clamp the sprocket side nut in my vice to work on them. the nuts are jamed together to keep them tight because they has to be a little space between them and the brake arm. As long as you dont tighten the big nut up against the arm it will work. There is a flat spot on both sides of the axel on that side that you can put a small crecent on and keep the axel from turning. At this point you just take the brake arm and cover off . Still no surprises. Now just slide the whole houseing off. The guts are right there. If anything falls out it is broken. The whole unit will stay together. The two brake shoes may stay in the houseing. If when you take it apart you shove them down while your taking the houseing off they will go out with the rest of it and stay put. If it has a coating of white grease on everything its pretty much ok. If its dry..seen 1 so far. then you might want to add some sparingly. Make sure to steal one of your wife's small paintbrushes and grease the bearing in the brake arm. Your lbs will charge you a bunch for this since your too scared to do it yourself. You can soak the whole thing in something..I used gas ,but thats dangerous , and then put them back together.Its really not rocket science. There are two pins in one part that have some small springs on them and when you turn them upside down the pins will fall out and its either real hard to get the two little springs back in or they leave on vacation never to be seen again. If there is any interest I can take some pictures and take one completely apart and show you how they go back together. I have changed an axel so it was pretty much all apart. still no big surprises putting it back together. If you have one that clunks as you pedal then its the sprocket is worn inside on the three little tabs. ..change it problem solved.
