bswinn Posted June 22, 2009 Share Posted June 22, 2009 Alright not exactly sure how to describe this one but here goes. My '77 xs400d has a mechanical speedometer. The speedometer is driven by a gear assembly attached to the front wheel. This gear assembly is turned by a special nut inside the tire. This nut was broken when I bought the bike. But when i bought the bike the front forks and tire were off so I did not see how the front tire was set up. From the manuals it appears that the rotor goes on the right hand side of the front tire, and the speedometer driving gear assembly goes on the left. Before reassembly I decided to break down the gear unit and recondition it by lubing it up since it was pretty damn dry when I got it. Now that it's assembled the gear inside turns one way VERY smoothly like I think it should. But if I try to spin it the other way it binds up pretty badly. Now that shouldn't be a big issue except for the fact that according to how I picture it when it's put on the bike forwards is going to be the direction that binds up the gear. I'm thinking that will lead another of those special nuts broken. Is there anyone out there that is familiar with these mechanical units? And if so do you know if it should spin freely in BOTH directions? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted June 22, 2009 Moderator Share Posted June 22, 2009 the speedo drive goes on the left hand wheel( as sat on the bike! ) there's not a lot really to go wrong with them as they are mechanically simple utilising a worm drive driven off a "special 2 teeth washer" . this engages with the gear drive, which in turn mates with the worm drive. schematic recheck the spacers and washers are in the right order and that the drive engages in the lower fork properly. drewps Link to comment Share on other sites More sharing options...
JimR Posted June 23, 2009 Share Posted June 23, 2009 Alright not exactly sure how to describe this one but here goes. My '77 xs400d has a mechanical speedometer. The speedometer is driven by a gear assembly attached to the front wheel. This gear assembly is turned by a special nut inside the tire. This nut was broken when I bought the bike. But when i bought the bike the front forks and tire were off so I did not see how the front tire was set up. From the manuals it appears that the rotor goes on the right hand side of the front tire, and the speedometer driving gear assembly goes on the left. Before reassembly I decided to break down the gear unit and recondition it by lubing it up since it was pretty damn dry when I got it. Now that it's assembled the gear inside turns one way VERY smoothly like I think it should. But if I try to spin it the other way it binds up pretty badly. Now that shouldn't be a big issue except for the fact that according to how I picture it when it's put on the bike forwards is going to be the direction that binds up the gear. I'm thinking that will lead another of those special nuts broken. Is there anyone out there that is familiar with these mechanical units? And if so do you know if it should spin freely in BOTH directions? Hi, sounds to me like a worn out worm gear or its housing Regards Jim Link to comment Share on other sites More sharing options...
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