Quote:
Originally Posted by rupecopp
Ok to the gearset into a local bike shop and he said the one of the forks needed replacing, and the dogs on third had lost the sharp edge. So it was new third gear and the gear the dogs go into (expensive) or I could get the gears machined (any opinions on this?).
I took the secondary pinion gears off a min ago to look at third and all the dogs look the same to me. A bit of wear but nothing to bad, but the needle bearings on third have had it. 4 needles fell out, and are shattered, and 2 are completly missing? So is this something caused by skipping/clunking gear, or why it was skipping/clunking???
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I think we're getting somewhere. I've had gear dogs machined (undercut) before in a "free" yamaha i was given. It worked fine, but I was always conscious of that issue, so i was careful when shifting with that gear combo.
If the pinion on the III gear secondary had bad bearings, the gear would not run perpendicular to the shaft, and this would cause lateral loading on the gear combination. This lateral loading would put force the shift fork to react against it, and thus wear the shift fork. How does the countershaft look? did the bearing failure ruin the shaft?
Also check the secondary pinion (pinion IV) which engages secondary pinion III to engage it. There is some reason that the bearing failed. Perhaps bad dogs on secondary pinion IV forced misalignment with secondary pinion III.
If the shift fork is just worn and not bent, you can build the ends of the shift fork up with some weldmet, and then grind the excess off. Use a good shift fork as a reference. Shift forks aren't that expensive, but if you have access to a welder, you can save yourself some dough. I've done this before, and it's worked fine. (I try to be a mechanic more than a parts replacer.) If it's bent, then you have to replace it.
Good luck.
blitz