Dremel Fix

[BillyRok]

Need to do the transmission fix, I've been reading up on it and trying to convince myself I can get it all back together. Just wondering which model Dremel would be best to use and which grinding stones (size, composition) I need to do the job...don't want to start and not have everything I"ll need.
Appreciate all your help.

[motoman]

Any Dremal and an aggressive diamond stone in the small diamater range.

[DGXSER]

The tech tip I gives model no. for the grinding stones suggested. Those are the ones I have always used.

Print out the directions from the tech tip, take them to the garage with you as you disassmble the bike. The pics and all are VERY hepful. Also, take your own pics as you disassemble. I take one after every part is removed, so I have a clear pic as I reassemble of the order of parts and locations or alignments.

Most of all, do not be afraid to come and ask questions here. Even if you just need your nerves settled. My first trip into the tranny for this surely had me a bit flustered. Hardest part tends to be getting the gears back in. It is a trial and repeat...and repeat...kind of thing. Eventually they just seam to fall into place and you wonder what you did that worked.

[crazy steve]

I just did the gears on my XJ and used a air die-grinder with a 5/16" diameter carbide cutter. That worked great for the slots, did most of the grinding with this on the dogs then touched those up with a file. It's really not that hard....

[CatatonicBug]

I like a die grinder for the job myself too. I use a cutoff wheel for the dogs, and a 1/8" diameter, flat-tipped carbide cutter for the slots.

[jetmechmarty]

How do you get all of the slots and dogs to match using these tools? From my perspective, it appears that there is a risk of loading one dog once this thing is in operation.

[TomB]

How do you get all of the slots and dogs to match using these tools

I've just done the gearbox on my bike using an air die grinder.

To get the dogs equal you have to assume the dogs and slots have worn equally, first grind the dogs and use engineers blue or a marker pen on the dogs where you've ground then slide the gear back on the shaft and fit it into the mating gears slots and give it a rub in and out, check the marker pen mark or engineers blue to see if all are touching, take a bit more off the ones that are until all the dogs are touching and are equal, then you know they'll all drive without loading one too much.

Next grind the slots and use engineers blue or marker pen the same way, coz you already know the dogs are equal.

Worked for me

[DGXSER]

Marty, with the dremmel bits, the one TC recommends is very very sloce to an exact match for the hole size of the slots. As to matching the angle, admittedly, it is crude as in eye balling the angle to be the same. Not very close for an engineer or a jet engine mechanic. But, works well with MC gears from my experineces to date.

As to matching that the dogs all contact equally with the slots, I use playdough as a "plastigage" on the dogs, mount the gears on the shaft and twist the dogs int he slots to ensure I get coould solid contact. Compare the material on the dogs to see if it is even, grind a little as needed till they are.

It is not a 15 minute job, more like a three hour job to grind the gears if you take this level of accuracy into the project (unless you are one very talented grinder with amazingly accurate eyes). Btu it can be done.

[crazy steve]

How do you get all of the slots and dogs to match using these tools? From my perspective, it appears that there is a risk of loading one dog once this thing is in operation.

I'll go with what was said above. Basically what I did was grind on them until the worn spots were just gone, then check the width on the slots/dogs with a caliper to make sure they all matched. I then checked fit, and did a small amount of touch-up until I was happy. It was actually easier than I thought it would be...

The one thing that did concern me momentarily is these are surface-hardened cast gears and once you grind through the hardening, the base metal is pretty soft. Now this can be both a good thing and a bad thing; it's good from the standpoint that any minor variations in fit will probably 'wear to fit' quickly, so absolute precision probably isn't critical. And the fact that the metal is soft will help it withstand shock loads without breaking. The bad part is you may see accelerated wear, but given the number of bikes this has been done to and the very limited reports of further problems, the 'field testing' would seem to say this is a workable fix. Not the equal of OEM parts, but for a 'no-buck' fix a pretty good return on investment. If you beat the holy hell out of the bike, I can see the problem coming back quickly, but for most riders it'll work just fine...

[CatatonicBug]

It is not a 15 minute job, more like a three hour job to grind the gears if you take this level of accuracy into the project (unless you are one very talented grinder with amazingly accurate eyes). Btu it can be done.

The whole job can be done in 4-5 hours, including re-assembly of the bike. Cutting the gears is a heck of a lot easier than getting that countershaft back in the bike! I'd allow about 10-15 minutes per gear if you have a die grinder. It goes a lot faster than when using a dremel. It is rather crude, but a pair of calipers is uaually plenty for getting the cuts right.

[DGXSER]

Hmm...must be a reason I added...."if you take this level of accuracy into the project ".

[madmax-im]

I didnt do the dremel fix...rather ...I just bought new factory backcut gearsets from Yamaha and swapped the old ones out...they're still made BTW...As it was it took a few hours to do the process and I still had some troubles....
When you pull out the gears pay close attention as to how they are paired...one of my mistakes was putting 2nd gear on the shaft backwards so that it wasnt engaging with 5...you also should dry shift the gears before final re-assy to make sure they are working correctly...another thing I didnt do...
It wasnt until I broght the bike down to casa TC's that he and I got it sorted correctly...
While factory backcut gears are not cheap...they'll never break and I 'll never have to worry about that again. Well worth it in the long run...

[TomB]

Cutting the gears is a heck of a lot easier than getting that countershaft back in the bike!

I had a hell of a job getting the shaft out until I realised that with the clutch off the shaft that stays in, you could gently, using a piece of aluminium protecting the threads, knock the shaft through its bearings over to the gear selector side of the engine, this allows the shaft you're taking out to slip out very easily.

Assembling was easy too, once the two shafts are back in the clutch could be assembled with the main centre nut pulling the shaft back through the bearings to where it was.

The clutch shaft moved around 3/16" - 7/32"

[jetmechmarty]

Some good ideas for sure. I especially like the use of "engineers blue". I replaced 1st, 2nd, 4th, and 5th gear wheels on mine with new ones. I started hunting them at the first sign of trouble. I was able to source the four wheels for about $100. They sat on the shelf 2-3 years before I lost 2nd completely. I see that now it appears that not all of the gears are available and the ones that are, are very expensive. Therefore, it looks like next time, it's the "Dremel fix", like it or not.

[BillyRok]

Update with some observations and questions: I got everything apart using TC's write up, the wireless connection and a notebook came in handy! The motor is out of the frame and upside down on the floor to work on. I wasn't able to get the oil sensor out of the pan so I took the pan off with the sensor still in it...it will twist in the opening a little but won't just pull out like I expected...ideas? And last year I noticed a bit of oil dripping off the sensor wire...yamabond will cure it? I'd purchased a new T30 torx bit for removing the counter shaft bearing/oil cover only to discover mine had phillips head screws, had to buy an impact driver to remove them...they were tight! Used a 1/2" air impact to remove the main clutch nut since the motor is out of the bike, I guess I can't torque it back down until the motor's back in the bike since I can't figure out how to keep the shaft/gears from turning. Is it ok to use the old o-ring when reinstalling the oil pump or do I need a new one? Tomorrow I'll do the grinding of the dogs and slots. I used calipers to check the dogs before grinding and discovered they are slightly back cut now...about .015" wider at the top of the dog vs the base. I guess that isn't enough because they are still starting to round off. The tech tip says to grind the 5th gear dogs/2nd gear slots and the 4th gear dogs/1st gear slots...what about the dogs on the other side of 4th gear that engage the slots in 3rd gear? Do I grind these dogs and slots, too? And then I can use yamabond to replace all the gaskets that didn't come off in one piece?

A final note: to all of you who have taken the time to post all the tech tips with pictures that are available on this site, a huge thank you! When you are new to this game as I am, it's a huge help to take something apart while following along what somebody else has done before you...I kept thinking "hey, mine looks just like the picture!" What a great group of people, keep up the good work!