Look for thoughts & comments on bent shifting fork

[maddad]

Well I've gotten it all apart. Will be posting a bunch of pictures as there are not many around on what these things look like taken apart. Only thing I found a real pain was the oil pump chain guard. That was a bit of a bugger as you have to suspend the transmission chassis above the main block with some wood and put in a 6" long allen key to unscrew it.

Anyway, more to the point. The following two pictures are of the 2nd gear shifting fork and 2nd gear. The shifting fork I know needs to be replaced because of the wear. What I wondering if is people think the amount of wear matches the symptoms or do I need to look further. I think it does. When in 2nd gear if I come onto it real hard it will jump out of gear and then right back in. Felt like skipping a tooth on a chain but in this case skipping one of the dogs. But I do have to come onto it hard and doesn't do it everytime. (eg. did it twice on a run through the Dragon and then maybe only once on the 3000 km trip home).

Had the same thing on a friends Busa, his was consistently happening in 2nd gear and his shifting fork had the same type of damage but far more.

The 2nd picture is of 2nd gear. It looks good, except if you look at the part I circled in red, you can see a little ridge. This actually looks like its from the factory this way. The dogs are not angled off, nor do the mating faces on 2nd gear look warn. It's just the ridges that I'm wondering about. Any of you guys think this is normal or should I replace 2nd gear, which is rather pricey. But now that i look at the picture I see a little more wear then I expected.

 

[kamal]

I can only give you my opinion.

You may get away with replacing just the fork, but if it was my engine I'd replace both.

Looking forward to a full report with lots of pictures.

Thanks in advance.

Al.

 

[kawabeemer]

If any part is questionable, I'd replace it while the engine is apart. Better to replace a part that might be and issue than to have to redo the job later.

 

[maddad]

Yea, I'll be replacing it. Just looked up the gear at Cycle Parts Warehouse and it's only $62. Not going to question it at that price.

 

[rPGoatBoy]

Yup, I'd replace the fork, that gear, and the mating gear with the male dogs that caused all that damage to that 2nd gear. I had to split my 2006's case to fix exactly the same problem, and my gears/shift fork looked exactly the same. If you want pictures, let me know. If you've got to the trouble of pulling the motor and splitting the case, why risk having to do it twice? Also you should consider a valve shim adjustment (if needed) and replacing the CCT with the updated blue dot version while the motor is out of the frame; those two jobs are significantly easier while the motor is out of the bike.

I also replaced the timing chain on mine at 27,000 miles cos I was in there.

 

[RossKean]

Ouch - looks like a big job. While I do all of the "routine" maintenance/repair on my FJR, that's out of my league. Hope you get it back together for the start of NB riding season. I have a bit more annual stuff to do on my bike but will maybe get it out for a short spin this weekend, if Environment Canada (weather forecast) knows what they are talking about.

How many KM on the bike?

Ross

 

[fudgejerkin1188]

Similar problem with one of my bikes but shifting forks were a lot worse and the dogs rounded. I ended up replacing the whole gearbox with a good second hand one

 

[maddad]

Looking closer at the picture, I will be replacing 2nd gear and the mating one as well as shifting fork. I've already done the blue dot tensioner a while back and plan on doing the valves this time as well. Not sure I'll replace the chain but that's just because I really haven't looked at it yet to see the condition or how much more work it would be to replace. Trying to stay somewhat out of the top end except for the valves.

Bike has 115,000 km on it. Bent fork was done on one bad shift and then slow wear after that. Not worried to much about putting it back together, everything came apart with out too much fuss which is where trouble happens.

 

[fjr vfr]

The problem is mostly bikes with high torque motors like the FJR and Busa. Hard acceleration in second gear puts very high stress on the shift fork and dogs. My 04 started jumping out of second gear and progressively got worst until I lost 4th gear and 2nd. At 115,000 miles I decided to replace the motor with a low mileage one from eBay rather than fix the gear box. I still have the old motor under cover in my shed. Cost for the younger motor wasn't much more than fixing the gear box and I get a low mileage motor. Good luck with yours.

 

[08FJR4ME]

Hope to see more picks and a write up on this if you have time. We could all learn from your experience. I am sure doing this repair isn't for the faint of heart.

Dave

 

[TownsendsFJR1300]

A similar situation on an FZ6 forum, a bad second gear with lots of pictures (very similar set up):

Page 3 and 4 very informative on the inner workings...

https://www.fz6-forum.com/forum/garage-mechanical-help/48071-broken-my-gears.html

 

[maddad]

Done.

And I guess pretty much as simple as that. Lost one washer for the muffler bracket when some parts got moved. Replaced with Canadian Tire washer. Had trouble with 2 bolts getting them out because I broke off the round allen head in bolt. Besides that everything stripped down very nice. Went back together very nice.

Engine is tight to get in but rather than trying to lift from body, there are three hook points on the engine. Tied it with straps and winched from the ceiling. Made for a nice slow and controlled lower and raising the engine. At 115,000 km, had 7 valves out by 20/1000. Replaced all gaskets and o'rings. 2 gears, shifting fork, gear shift rubber, foot pads, one of the smaller pieces of plastics and some extra bolts, etc. that had just gone missing or need to be replaced over time.

Total parts was right around $600.

Total Labour, about 5 months. Winter time project. Very much one piece at a time and as soon as I was frustrated with something, took a break and looked at it the next day. Never pitched any parts against the wall or banged on anything too hard in frustration. If I were to do it again I think I could probably have it in and out in 20 hours with a helper.

Still have to put the bottom plastics on and changes out the distilled water with engine ice. Went to start it and of course the battery was low. Couldn't wait so it was bump start time.

Brother In Law said he would push me down the hill if my cousin agreed to push it back up. Dropped it into 3rd gear, coasted about 50 feet, drop the clutch and it roared to life without a hick-up. No odd noises. Maybe a bit more power with the valves adjusted, maybe the same power, but certainly no loss of power. I was one happy guy.

Took it for a drive to meet the guys from wing night. Found one oil leak on stator cover, but also found that bolt to be a little loose. Still going to do a carb sync and put plastics back on before I'm official done, but very happy at this point. Wouldn't hesitate to replace any part on this bike in the future.

What I am most amazed with is how rugged these engines have been built.

 

[RossKean]

Congratulations! I know who to call if I ever run into transmission problems; I doubt I would have the guts to do that without some expert guidance. 142,000 km on my '07 so far without serious issues. Some valves at minimum clearance last check and will adjust next time.

 

[Fred W]

The problem is mostly bikes with high torque motors like the FJR and Busa. Hard acceleration in second gear puts very high stress on the shift fork and dogs.

I suspect that this is not the cause, but more of an effect (symptom) after the shift fork is already bent.

I would think that the reason this problem is always showing up in second gear (at least initially) is that you have to go through neutral to get from 1st to 2nd, which allows the transmission to freewheel a bit mid-shift before suddenly catching. That impulse is transferred back through the shift fork resulting in the tweak. Once tweaked the high torque motors can then push the dogs apart (and skip) under heavy torque application, even after being fully engaged.

 

[kaitsdad]

If any part is questionable, I'd replace it while the engine is apart. Better to replace a part that might be and issue than to have to redo the job later.

What he said. Do it.

 

[zed88]

Hope you took some pics you can post up. This is a neat project

 

[rPGoatBoy]

Done.

I have to say your experience pretty much mirrors mine, right on down to replacing the shift lever rubber. I also took five months doing the job, not because of any frustration with complexities or trouble acquiring parts, but because sometimes I felt like working on it and sometimes I didn't. There is no rocket science behind it, disassembly and assembly are fairly straight forward. It's a big job, and I've found that taking your time pays off in the end in not having to redo something rushed. Also having another motorcycle (96 Royal Star) helps fend off the urge to ride while one of your horses is down. If I were a flat rate mechanic I'd starve. I also have yet to do a throttle body synch, something I've been planning on doing since I put it all back together, but it's been too fun to ride and it currently runs fine.

For those of you who are interested, I can repost the Photobucket link again of when I split my engine; I tried searching for it on this site but the search feature only goes back 1 year.

 

[RossKean]

For those of you who are interested, I can repost the Photobucket link again of when I split my engine; I tried searching for it on this site but the search feature only goes back 1 year.

No limit on search - at least not using advanced search

This it?

 

[rPGoatBoy]

For those of you who are interested, I can repost the Photobucket link again of when I split my engine; I tried searching for it on this site but the search feature only goes back 1 year.

No limit on search - at least not using advanced search

This it?

That's the one, thank you!