TRANS. SHIFT PROB.

1982 xj750 maxim stuck/jammed in 3rd?? Took the left cover off and the mechanism that turns the shift drum. The shift drum turns freely about 270 deg. without any force at All. Am I looking at internal problems?

 

here is some info, they usually stick in first or second I think but check this anyway.I am surprised it is stuck in gear if you can rotate the drum that much. When you move the drum by hand can you check if you can get it to neutral by turning the back wheel at the same time. Check for small black plastic debris (chain guide breaking up) by looking through the hole in the crankcase as described in the emergency guidectomy.

https://xjbikes.com/forums/threads/please-help-cant-get-out-of-first.74037/

 

https://xjcd.org/emergency_guidectomy

 

When you look through that little hole above the shift drum, what do you see in yours? The first one or two shift forks should be somewhat visible traveling in their slots. Is it definitely stuck only in 3rd, and not jammed in two gears at the same time (that would stay locked up even when you pull in the clutch)?

 

I can see the drum turning yet it does not seem to be doing anything??
What I need is to talk to someone. If I could talk to someone that has experience with this trans. I have over some 25 -30 yrs of experience on man transmissions (Muncie,Saginaw, new process, ZF, and Mazda) so I know how the manual transmission works.
If someone would please call 306-561-7715’, I would much appreciate it.

 

Here's a photo that might help visualize the location of the shift forks and the drum. The hole you are looking through is on the upper left. Either looking directly or with a small mirror, you should be able to see the three forks moving back and forth in their slots.

If the drum is rotating 270 degrees and there is no movement from the forks, there isn't any fix that won't require a full teardown. I'm not even sure of a catastrophic scenario that would allow this. If your drum is rotating freely and the 3 shift forks appear to be moving properly, then it might be something fixable.

The chain guide debris issue mentioned above by Franz is a known issue, but the drum would not be free to turn. Maybe some debris jammed in the dogs on 3rd gear, but still not possible to shift through the rest of the gear positions and remain only in 3rd.

Draining the oil and looking for metal filings or black plastic debris from the chain guide is something else you could do.

Also watch this video by Mezzmo, around the 9 minute mark is shifter assembly, just for better info about what you are seeing through the hole and how things should work.



Can you see normal movement of the 3 forks (about 1/4" of movement)?

Are you sure it is stuck in 3rd (and how do you know)?

Does it stay only in 3rd as you turn the drum, or does it get locked in 2 gears simultaneously?

When pulling in the clutch, does the rear tire spin freely regardless of shift drum position?

 

If the forks are not moving all three pegs on the selector forks would need to have broken off not possible.

Is there anything wrong with this bolt? Is it tight?

 

Too hard to explain exactly what is going on, I am going to try a make a video of just exactly it is doing.
No, I don’t if it is stuck in 3rd
De-clutching releases the wheel(spins free)
No that bolt is tight

 

A bit off topic here but looking at the above picture Roast I noticed the same marks on two of the transmission gears mine have. I figured at some point in the past 42 years something caused slight damage but seeing yours are exactly the same leads me to believe this is how they were made. I've attached my picture from when I did the starter clutch. I wonder why they would be made this way.

Strange.

 

Problem solved apparently the guy that had this bike before me (sorry forgot tell you that I just got this bike) decided to switch the shifter to shift backwards, there is always somebody that knows a better way to do things

 

That's a new one. I know some race bikes and race wannabees use the opposite pattern. Not sure how you'd flip the ratchet around on these bikes though?

 

And God-Only-Knows what other clever things he did.................

 

You normally do it with the external gear linkages