Transmission Repair Alternative

[GNEPIG]

.. this statement was made by ag9123
XS Tranny Service Bulletin

This has probably been posted already but here goes anyway... During my years as a Yamaha mechanic, I installed a washer behind the main shaft that shims the gear cluster over a few millimeters or so as described in a service bulletin. This improves the engagement of 2nd gear and may be enough to restore proper shifting if done early enough. Some trannies are too far gone for this to work but it may be worth a try. there is very little disassembly required to install it though the details are a bit hazy after all these years...

.. after reading this, and studying my transmission, flipped over on the floor, for two days. i have figured out what this bulletin is about.

i have found that the dogs only engage the gears/slots by only about .115" to .120" inch, not very much considering there is alot more than that there. so i have figured out how to make 1rst and 2nd gears engage by about .180" inch.. here's my story, i hope it doesn't put you to sleep
.. by adding a washer/spacer with the thickness of .085" under the washer based bolt[#28], i have moved the Axel, Drive shaft[#14] over to the right by about .060". the washer/spacer has to fit inside the bearing and against the end of the Axel, drive shaft[#14]. this moves the second gear wheel[#23] closer to 5th gear wheel[#26]. this allows the shift fork to engage 5th gear wheel dogs into second gear wheel sooner and .060" deeper.
..by moving the axel, drive[#14] over you also move the 3rd gear wheel[#20] over and away from the 4th gear wheel[#19]. so you have to move the washer plate [#21] to the other side of the 4th gear wheel to regain .040" lost from the axel drive move.. some people will worry that the circlip[#22] will be exposed to force from the 3rd gear wheel[#20]. i dont think this will be a problem because the only force applied will be to the circumfrence of the gear towards the shaft and the only side force will come from when the 4th gear wheel[#19] engages the 3rd gear wheel[#20] pushing it away from the clip.. try your best not to distort the circlip[#22] when removing and replacing it. when replacing the circlip, put it on with the smooth side facing the 3rd gear wheel and you will not experience any problems with this.
.. ok, first gear!. originally 1rst gear wheel has alot of play side to side, about .016". that and the play the fork has in the 4th gear wheel grove[#19] and the shift drum groove, makes first gear a real sloppy engagement. it gets even worse after we move the Axel, Drive shaft[#14] over 060 tho!. so this is were we use an extra washer plate[#17], ground down to .050" and placed between the Middle Drive gear[#30] and the 1rst gear wheel[#15]. this will leave .010" play for #15 to float around in and first gear engagement closer and deeper.
.. * to whomever tries this change to their transmission: not all trans are made exactly the same, some are worn more than others and if your trans is alraedy to the point of being blown, then this may not fix it. you will have to measure YOUR trans to get exact numbers to set yours to. i suggest no less than .010" play for 1rst gear wheel[#15] and to make sure you have plenty of room for the dogs to whirl by the engagement gears safely so they dont try to engage when you put your bike on its side stand! this is adjusted by the washer/spacer placed under the washer based bolt[#28].. this change, with the second gear under cut, could make your transmission last for freakin ever!
.. this change has worked very well on my 79 special and i hope it helps others
..any comments, suggetions or questions?

[AKMac]

Thank you for this tip. I'll be diving into my tranny here shorty since I've got the dreaded 2nd gear skip. Is this fix similar to the one Bob Jones talks about?

[GNEPIG]

.. i'm not sure what the Bob Jones fix is, i think all he does is switch the washer[#24] from one side of second gear wheel[#23] to the other and undercut the dogs and slots. this is a pretty good fix also, you gain .040" more dog engagement for second gear but it does nothing to improve first gear engagement.

[GNEPIG]

Addendum

In your diagram, that spacer is shown WAY TOO BIG compared to what is in the fiche for the 81H/LH/SH and 82XJ's engines!! Here's a quote from the TECHNICAL DATA from the Yamaha parts site for the XJ!

: Drive Axle Bearing Washer for H/LH/SH/XJ
A new style bearing supports the right hand side of the transmission drive axle on the affected models. This new style bearing is a single row ball bearing rather than a double row bearing as used on previous xs11s. Since this new style bearing is 3mm narrower than the bearing previously used, a collar and washer have been installed between the bearing and the crankcase to maintain the proper clearances in the transmission. This washer is directional. IT must be installed with the beveled edge tward the crankcase and away from the bearing.

.. this statement has had me wondering about the two parts in the picture that i didnt recognize, since i have not seen these parts in any of the motors that i have. the washer plate[#29] and collar[#32] that are only in the 81 and 82 engines. i was wondering if these two parts would make a difference in the position of the axel drive shaft[#14]. the part numbers for the washer based bolt[#28] and the axel drive shaft[#14] remain the same throughout the years. which leads me to believe that there is no difference between the new bearing setup and the old, fat, two row bearing.. so the trans upgrade that is mentioned above should work for the 1981-82 motors also.
.. this is what my transmission looks like. I could not find any mention of the new bearing and spacers in my Clymer manual. it would be cool if there was mention of what the benefits are for the new bearing change.

[GNEPIG]

.. i beleive this is what everyone is looking for.
this bulletin is not model specific, it says ALL MODELS, particularly on the large- displacement performance models.. you will notice the part numbers for the shims/spacers [on the last two pages], our shims are in the list.
.. alright, i want the XS11/ God-like signiture under my name now

[prometheus578]

GNEPIG...
I've always worshipped you from afar.

[TopCatGr58]

Hey Gene,

Veeeerrrrrrryyyyy Interesting!! Thanks for digging it up!!

Around here, "god" = GURU, and you're only 171 posts away! Sorry, but you have to earn your "idle" worship!

Bowing in respect!! T.C.

[LoserShoes]

Hows about one of you moderators saving a copy of that local to this site so it doesn't go away sometime in the future? I saved a copy local on my machine, but others might not do so.

Steve

[81xsproject]

I am very interested in this, especially since my trans is still problem free. What we need now is one you almighty guru's to perform this, take tons of pics, and write up a super-sweet tech tip...


...Please

[AKMac]

I'm willing to do the write up/tech tip on my bike if someone who knows what there doing is willing to help. I feel pretty good in my mechanic skills, but transmission work has always intimidated me. Anyone want to take a vacation to Utah?

[GNEPIG]

Anyone want to take a vacation to Utah?

.. hey Mac, maybe you would like to take a vacation to florida, i will help, i might know a little about your transmission. i have spare parts i could share also and the tools required for the job.

[GNEPIG]

i suggest no less than .010" play for 1rst gear wheel[#15]

.. in the last part of my post at the begining of this thread, i made a statement that you should have no less then .010" side play for first gear. at the time i did this fix to my trams i had no specs to go by so this was my conservative estiment of how i thought the side play should be. i will be going back into my trans and changing my first gear side play to no less than .003" and no more than .005". while i'm in there i will also under cut my second gear and try to see if i can make fourth gear engage a little easier.
.. the part about the bulletin that has nothing to do with us: measuring drive axle side play the three steps and the example, are all pretaining to bikes with the engine cases that split down the middle[split vertically], dissregard this part, measuring our drive axle clearance is not so complicated and really only requires a set of feeler gauges
.. other than slightly missjudging the gear side play, i think that i nailed that bulletin, almost dead nuts before even seeing it..

[79XS11F]

Originally posted by GNEPIG
.. i'm not sure what the Bob Jones fix is, i think all he does is switch the washer[#24] from one side of second gear wheel[#23] to the other and undercut the dogs and slots. this is a pretty good fix also, you gain .040" more dog engagement for second gear but it does nothing to improve first gear engagement.

I have my cases split on my 79 1100F and was going to do the Bob Jones "fix" but there was nothing in what I read about undercutting the dogs and slots. The short article I read contained only one paragraph on this trany issue. It simply said to change the position of that washer in relationship to the second gear wheel.
What do you mean by "undercut" the dogs and shots? I would really like to not have to split the cases again for a VERY long time.
Rob.

[TopCatGr58]

Check your PM mailbox!

Hey Rob,

Sent you a PM with a link to the Tranny repairs tech tips! You'll find it interesting reading!
T.C.

[JonhDough]

The short article I read contained only one paragraph on this trany issue. It simply said to change the position of that washer in relationship to the second gear wheel.

i have read this on the Bob Jones site also, and didnt see anything about undercut either. i also have my transmission apart and was wondering which is the right way to fix it.
Jonh