A shifty problem

[SmokyOwl]

On my 2006 Fatboy I'm having an occasional issue where when downshifting I sometimes shift into nothing.  Shifting from 5th to 4th, or 4th into 3rd, I shift and it's suddenly in neutral- then cannot go back into any gear until I come to a complete stop, which isn't that big of an issue because I'm downshifting to a stop anyways.  It's like everything lines up in the transmission perfectly so nothing functions.  I wonder if a shifting fork is bent?  It wouldn't surprise me at all since day 1 I had the SE 6-speed installed going from 5th to 6th has always been a bit dodgy with a often two-step feel to engagement.

[smoserx1]

I am no transmission expert at all but just looking at the diagram of the shifter mechanism I am wondering if you have excessive wear on the cams on  the end of the shifter drum or perhaps the cam follower (or both).  I mean as you shift the drum has to move the forks enough to engage one gear set  and disengage the other.  If it does not rotate that drum enough downshifting it looks like you could end up with the higher gear disengaging but the lower target gear not making it to engagement.  Anyway, just a  thought.  I guess bent or worn forks could cause it too.

[JW113]

Hold on a sec. You say that when this happens, say shifting from 5th to 4th, it goes into a "false neutral", and continuing to tap on the shifter lever, it won't go into any gear until you stop, and then it will?

The pre-2002 five speeds were notorious for finding false neutrals, esp during hard up-shifts. But they would always recover by banging the shift lever again. I have no idea what goes on with those SE 6 speeds, and what you are describing sounds bizarre. First thought in my noggin is something is going wacky with this:

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The shifter arm inside the trans has a spring loaded pawl that grabs the pegs on the shift drum and pulls on them, rotating the drum one way or the other. If the pawl is binding (?) or spring is broken, that will cause some odd shifting behavior. Don't understand why coming to a stop causes it to "reset" and start working again.

Time to pull the trans top cover and have a look-see?

-JW

[SmokyOwl]

Hold on a sec. You say that when this happens, say shifting from 5th to 4th, it goes into a "false neutral", and continuing to tap on the shifter lever, it won't go into any gear until you stop, and then it will?

Exactly- it will not go down, it will not go up.  It's lost in la la land.  I tried banging it into gear once to no avail but I rather not because one, the one time I did it didn't do anything, and two I don't want to bend or otherwise damage anything because it's already in an abnormal state and I don't want to make it worse.  However I'll try to go down and up like I normally would shift and it's like I have no transmission- there's no catching anything, no slipping off, absolutely zero engagement.  It doesn't happen very often, but I do worry in the future in an emergency situation or something when I really need that gear.  My guess is something is misaligned or otherwise out of whack on the drum but I'm far from any expert.  It be nice if I could waddle the thing to the sidewalk and open the case when it happens next time but who knows, it's only happened about 3 times in the last 2,500 miles or so so it's not really a repeatable failure.  Is it possible from like light/lazy shifting?  I don't think I was doing any strenuous riding when it happened.

I am very confounded how it'll suddenly work perfectly after the bike has come to a stop, my theory is something moves when the bike's momentum is stopped forward/backward slightly when stopped.

I'll be visiting my bike in storage this weekend, hopefully I can grab a pic but I doubt it'll show anything useful if everything is where it's supposed to be.  Damn cold out there too right now.

[kd]

The Main drive gear is being driven by the chain.

[SmokyOwl]

The shifter arm inside the trans has a spring loaded pawl that grabs the pegs on the shift drum and pulls on them, rotating the drum one way or the other. If the pawl is binding (?) or spring is broken, that will cause some odd shifting behavior. Don't understand why coming to a stop causes it to "reset" and start working again.

I've also had this pretty repeatable shifting problem when going into 6th gear, like I said it's like a two-step engagement where it gets hung up midway through the shift movement, and you have to bang it into place for full engagement.  I'm always making sure I have full engagement, but I fear this repeated banging is doing damage to something inside as the problem seems to have gotten worse over the last 8-9,000 miles or so since the installation.  It occurs as often as you could hit heads on a coin flip, quite often- and it's been that way since day 1.  I'm certain this is from poor installation of some sort but the dealership went belly-up a month later so I couldn't really go back and complain about it.  I also fear that this banging could have attributed to the problem I'm having with the downshifting issue.

[GrizzlyWolf67]

I was having a similar issue with my 90s heritage, going into a false netural sometimes, and finding netural when the engine is running is impossible, got used to just reaching down and popping it in by hand, I first thought the shifter bushing being worn was the issue, fixed that, still not shifting netural, but found a damaged front pully and 5 th gear main shaft splines, transmission is in a local independent for repairs, I hope he can address that too. Got a new compensator, clutch plates and steels, and pressure plate, waiting on the shop to call to pick up my trans so I can get everything back together. If you figure out what is going on please post what you find out. Good luck brother.

[kd]

This video link was in the Baker Gearhead newsletter to my email today.. I remembered this thread and it seems to be relevant to the issue.  Check it out and see if it is what you need.

[sbcharlie]

You should shim 3rd gear and back cut gears. Works quite well you might isotopic trans gears. They shift quite well doing the above