Transmission Gremlins

[LenB]

Over this past winter, on the list of projects undertaken on my '80G, was transmission work. Was able to source a complete trans from an '81 Special and swapped out 5th and 2nd wheel gears, a scored shifter fork and relocated the necessary washer. After a couple of chilly rides, 2nd feels pretty solid but some shifter concerns are still evident. I roll up to a stop, downshifting all the way but the shifter seizes when I try to go down from 2nd to 1st. So as not to hold up traffic, I'm forced to do a 2nd, sometimes 3rd gear clutch-slipping crawl off the stopline. Once rolling again, things appear to be temporarily corrected. There must be some clearance issues because I've had to replace a mangled star washer at the end of the shift drum in the past and if that isn't holding the dowel pins in place, all hell breaks loose. Is this the result of 'cumulative slop' - combination of minor wear in many areas or can something be shimmed / re-spaced to avoid this? Any/all input greatly appreciated.

[Radioguylogs]

I don't if it helps, but I had a related problem on y '79SF. Sometimes when I was shifting up from second to third gear, it wouldn't shift. I found the shifter was sticking in the 'up' position, and I could tap it down and it would work.

I tried replacing the spring and it wasn't any better.

It took me a few years to eventually realize the shaft that holds the shift lever was bent, and it was binding. I changed the shaft and it was fixed.

I wonder if you might be able tap it up when it was "stuck"? (for diagnosis)

JAT.

[LenB]

Yes, can shift up. Shifter jammed and won't go down. Part of the work performed involved changing out the shifter shaft and shifter pawl/lever assembly with parts from the other transmission, so, unless they're both bent, that's not likely the cause. It seems the shift pawl/lever and the end of the shift drum do a very close dance every time I shift and sometimes they step on each others toes. Old parts taken out show contact between the throw limiter studs on the back of the shift/pawl lever and the star washer, so, silly me, I thought I had the problem licked by changing out the damaged parts. Apparently not. I've attached pix of the damaged parts for analysis.

[Radioguylogs]

Very peculiar. It seems to be above my pay grade.

[motoman]

I suggest checking correct attachment of shifter spring, with it having been preloaded before attaching hook retainer portion. As stated, check shift shaft for straightness.

[cajun31]

Make sure the bike is in 2nd gear before aligning the shift pawl marks.

[LenB]

Upon further head scratching analysis, the trans appears much more cooperative after proper clutch adjustment. Typically, I like the clutch to start hooking up just off the grip with lots of play in the lever. No, no, no, no. Very fine line between being able to shift and proper disengagement. This setup would cause all sorts of problems shifting/downshifting when the clutch didn't disengage properly. Upon further reflection, in my frustration, stomping on the shifter probably caused the damages. Now, actually staying on top of the proper adjustments, the transmission bits can properly freewheel between shifts and not get dragged along by a binding clutch. Sometimes searching for answers requires a little introspection. Who knew?

[cajun31]

Thanks for the update. One of those things you tuck away and try to remember later when you need it.