Sounds like in all your endeavors with motorcycles, you've never rebuilt a tranny..

If the issue only occurs in first gear then first gear is blown. Read the manual on the transmission power flow.. In the tranny, the dog clutch is nothing more than pins on the side of a gear that mate with another set of pins on a another gear / drive ring. The shift forks/drum force the 2 set to mate to put the tranny in gear.. The problem stems from the pins being worn. Under load they slip apart. You'll need to replace the parts that have the dogs on them and the related shift fork.

 

 

Max, While you're wrong about me never having had to rebuild a tranny, I think at this point that explanation is about the only thing left that I can hang my hat on. I HAVE rebuilt a trans or two, but not in recent years. My experience with trans problems has been pretty much on the 'shift' side....... or lack there of! I do understand what you're saying, but I've not had the experience of that kind of 'symptom' from that kind of 'problem'. Those shift dogs are not under any kind of 'spring' tension, and they are actuated by the forks and drum rotation. The fork position has to move into the selected gear position in order to 'activate' a given gear. On a motorcycle trans, the rotating drum being what actuates the fork movement, theoretically the gears can only shift 'up' from 1st to 6th or 'down' from 6th to 1st in sequential order. Unlike an automobile standard shift where you can put the thing in any gear you chose just by moving the shift lever around. Anyway, my question here is this: If the trans is having the shift dogs 'de-couple'. then in turn, would not the shift fork have to move with the dog as well......or as I HAVE experienced....would not the thing simply jump OUT of gear? OR..... are you saying that the wear on the ears of the dog is sufficient for the coupling aspect to actually disengage momentarily under high torque load, then re-engage as the torque is reduced? The bike never had a 'jumping out of gear' issue, nor does it now. After this slippage, I've never had to re-shift it into first.......

Stiggy and 702, good thoughts, but no metal shavings or filings around the trans pully indicating any problem there. Further, with the 'launch' load also being pretty significant, I would think a stripped pully/spline would show up on break-away from a dead stop as well....which it does not. As to the tire thing, I think if the tire were rotating on the wheel it would strip the valve off the inner tube. Perhaps a more appropriate consideration on a 'tubeless' wheel, but this spoke wheel with the inner tube I would think would tear up the tube if the tire were spinning on the rim. But, just for eliminating that as a consideration, I'll give that a try too.

We have some serious weather problems here right now. I'm also a 'boater', and my home is on a creek just off the Chesapeake Bay. This Hurricane Debby is causing some severe flooding right now, with tides rising dangerously all around the area. My dock is under water right now, and my neighbor's boat has already floated off his lift. My smaller boat is all the way 'up' on my lift and the bottom is already touching the water. Another few inches of tidal rise and I too will loose a boat off it's lift. This will also cause electrical issues so boat lifts will fail to operate. This gets worse if the boat is 'partially' on the lift, as with those like mine where it's also tied to the dock so it won't float away. When the tide goes down, the boat could literally be hanging off the side of the lift and capsize into the water. Not good! So, for the moment, my attention is focused away from the garage and into the creek! But, more later. I'll be back to the bike in a day or two......assuming the storm pass by then.

 

Looks like a second gear banger..

 

Uncle Larry, those pics just appeared in my thread here. The first pic being the 'shift dog' as I would call it, then a gear (with the slots for the dog ear insertion to activate that gear), and finally the forks. I note some wear on the one. Anyway, thanks for posting that. Are you in agreement with Max that this might be the source of the problem? Also, is that actually a 'first gear' gear and shift dog?

 

If you've never checked the dog clutches in a constant mesh tranny then you don't know how to rebuild them. Those "dogs" get rounded so they no longer hook together. The shift fork is the spring as it bends and burns.. Larry's example is what you'll see but for first and not second. My first rounded dog clutch was a Honda S65 back in 67. I've rebuild a bunch of trannies.. Honda (bunch), Yamahas, Triumphs, Nortons, BSA, HD (tho have not done the 6 speed), Maico and a few others.

Stripped splines means total loss of motivation. You go nowhere quickly..

 

2nd gear in the Yamaha 1100 Special was VERY fragile ... Did several of them for friends

 

Don't know much about rebuilding a trans but I'm sure enjoying the read.
Hats off to you guys

wharfcreek Best wishes on getting through the storm Sir





WP

 

In his case it's second. Same clutch dog set and shift fork but the first gear has been removed. Fork will be burned on the other side..

 

I think I'm in the process of seeking a complete trans unit to install. Seeing 'used' units for $600 give or take (plus shipping). Seems a reasonable way to go. When I get one and install it, I can then take apart the original unit and spend some time evaluating it. I'm sure I'll find evidence of what Uncle Larry posted above.

For the record, most of my 'trans' experience has been on the older Yamaha XS650 bikes.......or cars. I've probably been in to more automatic units than manuals in the 4-wheel world as well. I'm actually ASE certified in automatic trans repair. So, not a complete dolt on this stuff. What strikes me as odd is that this symptom is a new one on me!! As a guy who's been riding and wrenching for 60 years now, you'd think I'd have experienced this in the past. I have not! Maybe just lucky? Who knows.

Anyway, it's been 'educational' ..... not to mention 'frustrating'!! Frankly, I'm not a big fan of the softail design, mostly owing to the rather difficult nature of removing the oil tank. PITA!!! Beyond that, just another Harley...... I guess. So, onward for now. Returning the bike tomorrow to it's owner, and he can ride it for now, problem 'un-resolved'...but at least the bike is operable. And, as soon as I find a good trans for it, I'll put that in it for him and hopefully that will solve the problem for good!!

Thanks to all for the contributions!!

Tom D.