XJ11 Transmission fix questions

[koehlerki]

I'm having problems with my XJ11not staying in first gear. So, I flipped it over and here's where I'm at:
Counter shaft bolt was completely loose and had worn to a point on the threaded end and a rounded top on the hex end.


1: What caused the bolt to back out? My dad did the 2nd gear dremmel fix in 2001 or so, then I bought the bike from him and rode it for over 15 years with no issues. There were no extra shims or washers.

2: Would this be a good reason for the bike not to stay in 1st gear? (I assume yes, but would like to know the mechanical reason why).

3: I have a nice set of gears that have no dog or slot issues that I have put in. I did the washer swap first on the new set. Thankfully I had an extra counter shaft bolt. I bought some red locktite and plan on using that. Do the threads and receiving end of the shaft need to be oil free for the locktite to work?

4: Looking at microfiche for the XJ it shows a washer before the countershaft bolt. But in some other images, specifically this one, there isn't one shown. Difference from XS to XJ perhaps? I neglected to note if this washer goes on the outside of the case or inside of the case. I assume outside. Am I right?




5: I don't have shift forks to compare so would love your thoughts on these. How do they look?



Once its all back together, I need to sell it if anyone is interested. It's listed in the for sale forum here. Thanks for your help!

[bikerphil]

Yes, use blue locktite on the replacement bolt, with red, you would have problems taking it apart next time. Spray brake cleaner on all the threads before applying.

The 81-82 models use that extra spacer. They changed the size of the bearing behind it and added that spacer to compensate. It goes between the bolt and the bearing.

The reason for first gear failure is the dogs/slots on the gears get rounded from dropping into first gear from neutral. When at a stop, the engine should never be higher than 1100 RPM's or prolonged abuse will cause eventual failure. The shaft drive provides no cushion like a chain would.

It is hard to say if just the loose bolt would alone cause the skipping, I've never had that happen.

Your shift forks look pretty good from what I can see.

[Radioguylogs]

This wear was enough to cause first gear skipping in my SF with 15 miles:

[DEEBS11]

I know many of you have "dremeled" the dogs and it worked and results are the proof. However, I would not hand cut those gears. You need to send them out to a machinist to get properly machined so all the angles match. It is such a pain to get the cluster out of the bike, why would you risk ever going back in there with a half assed repair. I have a spare cluster on the shelf with back cut gears and the washer switched just waiting for the day that I might have issues.

[DEEBS11]

[LenB]

Our Aussie friend Steptoe's approach is worth a mention.(especially when a local machine shop here quoted $500) Trying it out on my V45 rebuild. Maintained a 2.5 degree angle on 2nd gear dogs and slots, all making good, solid contact when mated. Seems Honda gears are made of a much softer metal than Yamaha's. No problem carefully removing metal with a burr grinder bit on the drill press. Lots of free apps you can put on your phone to get exact angles. Swapped out damaged shift drum & forks, too. No room for any washer swapping in a Honda 6-speed gearbox. In the process of reassembly now. Too old for light to light drag racing (although just can't help myself when some yuppie revs up their automatic beemer beside me ) Driving nice = longer lasting repair.

koehlerki - double-check the thickness of the all the tips of the shift forks - the smallest one looks a little worn to me. Also be sure all the grooves in the shift drum are intact with no indications of wear. There are a lot of nasty lateral forces at work when gears pop out of position.New replacement parts are made of unobtainium and good used parts are getting harder to find. I also found that good clutch adjustment and thinner oil for cool weather riding reduces the force of first gear engagement and subsequent wear. Good luck with your rebuild!

https://www.youtube.com/watch?v=nor4OygvIHw&t=12s