grinding noises in the gears

[MindWebs]

see if you have a fastenal by you..

http://www.fastenal.com/web/locations.ex

they might have some..

thay have all the stainless bolts you could want for your bike..

just a thought..

[DGXSER]

That bolt is a very specifically machined piece. The shoulder width and all seems pretty critical to me. Not to mention strength. If it were me, I would try Andreas Weiss or put something in the parts needed forum. With all the motors I have seen folks post they have laying about, there should be a spare or two floating around.

As to taping that shaft out, looking at the bolt, it seems it left some threads in there. I would think he will need to do something to get them out before the new bolt will go in.

[trbig]

Yes, those threads are going to be really wiped out in the beginning of the shaft. What you need to do is buy a couple regular metric bolts that are that size and thread pitch and use those to tap some new threads in the first part and get you back to the threads past that point that are still good. It will be like cross threading the first bolt... 2nd bolt will be better. Hopefully by the 3rd bolt you'll be able to use that replacement stock bolt without ruining it.

Tod

[Ivan]

I have been through two bolts, and the threads in the shaft don't get boogered up as badly as you might think. Like I said that shaft is hard. It seemed to be nearly as hard as the tap I tried to chase the thread with. The bolt is also very hard, but not nearly so as the shaft.

As far as I can tell, a hard bolt, that has 10.9 on the head would work, with a good thick washer that would probably need to be machined. The bolt just holds the shaft from sliding back and forth. The bearing under the bolt is locked in the case via a snapring on the inside of the case.

[trbig]

the threads in the shaft don't get boogered up as badly as you might think.

My bolt looked just like his and the threads for the 1st 1/4 to 1/2" were absolutely trashed. If it wasn't for the bolt being so long threaded to where I could catch some good ones behind that, the shaft would have been trash.

What amazes me, though, is the gear teeth on the back side of the clutch basket can do that and there wasn't a mark anywhere on that gear.

Another thing, though, is if you haven't, make sure you remove your oil pan and clean it and your oil pump screen well. There will be lots and lots of metal shavings in there. A magentic oil plug will help pick up anything you miss.

Tod

[Ivan]

L I B.

There you go. Check the threads on the shaft.

Yeah, the clutch basket gear doesn't even look touched on mine either. Amazing.

[3Phase]

Ouch

CavBird, I can only see the top strips of your pictures. Something is wrong but I think I can tell from the follow-up posts what happened. I hate to say it but it happened to me and you need to check 2nd and 5th gears for damage. The explanation is somewhat long-winded but I dug up the Yamaha XJ1100 transmission diagram to help because what happened is actually very simple but difficult to explain and it's important.

The bolt that you found, bolt #28 in the parts diagram below, came out of the transmission drive axle #14 behind the clutch basket. You should see a small ridge around the outer circumference of the head of the bolt. The ridge holds the washer #33 aligned and positioned at the end of the transmission drive axle when it's installed and torqued.

That's important because the drive axle is held at a predetermined torque and position at the right side of the transmission case and that position determines the amount of clearance between the dogs and slots on 2nd and 5th gear, #23 and #26, at the other end of the transmission drive axle!

The bolt also holds the drive axle inside of bearing #31 and it holds the middle drive gear #30, collar 1 #13, washer #17 and circlip #18 tight against the inner race of bearing #31.

If the transmission drive axle is too far to the right there will be too much clearance between 2nd and 5th gears and the dogs and slots won't engage all the way. The dogs and slots will begin wear out and round off under load and the transmission will begin to slip until, eventually, the transmission won't stay in 2nd gear.

If the transmission drive axle too far to the left 2nd and 5th gear will be too close. The 5th gear dogs will hit 2nd gear lands next to the slots as you ride the bike and they will begin to destroy one another. Even if the bolt (remember the bolt? Bolt #28 behind the clutch basket that you found in the clutch cover?) is Locked in place the repeated impacts can knock the bolt loose from the end of the transmission drive axle. The Bolt #28 will then unbolt itself into the back of the clutch basket and will get ripped out of its hole.

You need to check the transmission gears to see if they were damaged when the bolt began to loosen and the transmission drive axle became more and more free-floating and the gears could hit one another.




Regards,

Scott

[trbig]

You need to check the transmission gears to see if they were damaged when the bolt began to loosen and the transmission drive axle became more and more free-floating and the gears could hit one another.

Since he has the bike upside down, I'd check the gears, but that shaft is going to get very little (if any) play back and forth. Yes, eventually it would cause wear to the bearings as they aren't/weren't designed to guard against lateral movement, but it is locked into place by the screwed in bearing/cover from the other (Shifter) side.


Tod

[3Phase]

Since he has the bike upside down, I'd check the gears, but that shaft is going to get very little (if any) play back and forth. Yes, eventually it would cause wear to the bearings as they aren't/weren't designed to guard against lateral movement, but it is locked into place by the screwed in bearing/cover from the other (Shifter) side.


Tod

Tod, I just finished fighting with Bolt #28.

No disrespect, Super Guru! (genuflecting) but the transmission drive axle 'floats' in the inner race sleeves of the left and right side case bearings. The gears will be destroyed long before the bearings.

The drive axle and the gear stack are not held in place by the left side shifter cover bearing, they're just contained inside of the transmission and neither bearing inner race sleeve will wear. Bolt #28 holds and positions the drive axle against the right side case bearing and 4th and 5th gears are positioned on the drive axle by the shift forks. If the drive axle moves, even a few thousandths, 4th and 5th gears remain wherever the shift forks have them positioned and the neighboring gears, fixed to the drive axle, move closer or farther away.

Changing out washer #17 for a thicker washer is the fix recommended in one of the Yamaha Technical Service Bulletins. I forget who discovered it and the website is moving at glacial speed for me at the moment, hang on... <Search Music> GNEPIG! </Search Music>


Basically, Yamaha's thicker washer fix moved the transmission drive axle over to the left a few fractions of a millimeter so that 2nd gear and its slots on the drive axle were closer to 5th gear and its dogs as positioned by the shift fork. The shift fork positions 5th gear, not the axle, and when the right side bolt #28 comes loose the axle will float inside the case.

The drive axle doesn't have to move far because the space between the 5th gear dogs and 2nd gear lands is quite small. I don't remember what the stock clearance is but after doing the 2nd gear washer addition (added one extra washer and machined 2nd gear to fit) there was only a few thousandths clearance between the 5th gear dogs and the 2nd gear lands. Too close and they hit one another; too far and the dogs don't go far enough into the slots.

Bolt #28 is special and it's a very important bolt.


Regards,

Scott

[trbig]

No disrespect, Super Guru! (genuflecting) but the transmission drive axle 'floats' in the inner race sleeves of the left and right side case bearings. The gears will be destroyed long before the bearings.

The drive axle and the gear stack are not held in place by the left side shifter cover bearing, they're just contained inside of the transmission and neither bearing inner race sleeve will wear. Bolt #28 holds and positions the drive axle against the right side case bearing and 4th and 5th gears are positioned on the drive axle by the shift forks. If the drive axle moves, even a few thousandths, 4th and 5th gears remain wherever the shift forks have them positioned and the neighboring gears, fixed to the drive axle, move closer or farther away.

Well... Just happen to have a motor with the case split and acces to that bolt (#28). I just loosened the bolt and that shaft doesn't float or move. I even screwed the bolt in partially and tried pulling back and forth with some channel locks just to be sure. Nope.. doesn't move and isn't free floating. The bearings and cover have it locked into place.

I never had any gear problems when that bolt backed out on me. The bike ran fine through the gears to get me home except for that grinding sound (Clutch basket eating the bolt).

I stand by my innitial statement.


Tod

[trbig]

I just went and looked at a set of the gears on the shaft. On each side of that shaft, you have a smooth part that fits inside the bearing. Then you have a splined section that fits up against the side of the bearing. Both ends of this shaft are built this way and it would be impossible for it to float unless it wiped out the bearings. The bolt simply holds it and keeps it from lateral pressures against these bearings.


Tod

[trbig]

And also...

Changing out washer #17 for a thicker washer is the fix recommended in one of the Yamaha Technical Service Bulletins. I forget who discovered it and the website is moving at glacial speed for me at the moment, hang on... <Search Music> GNEPIG! </Search Music>


Basically, Yamaha's thicker washer fix moved the transmission drive axle over to the left a few fractions of a millimeter so that 2nd gear and its slots on the drive axle were closer to 5th gear and its dogs as positioned by the shift fork. The shift fork positions 5th gear, not the axle, and when the right side bolt #28 comes loose the axle will float inside the case.

If you place a thicker washer at this point, all you'll do is move 4th gear further away from 1st gear. (That there's already a problem meshing together deep enough) You won't be moving 4th any closer to third though, since there is a clip and washer preventing that. On the other side of 3rd gear, moving towards 2nd gear.. there is a collar milled into the shaft.(Where the #14 is pointing to) No amount of spacing changes done to one side will affect the other side because of this. If you simply put a thicker washer in, then you have messed up the spacing and the clip (27) won't fit into it's groove.

On the other side of the shaft, moving the washer (#24) from the side of 2nd gear it sits on to the other side to be up against that collar, will move 2nd towards 5th and fix a lot of the problems. Since the spacing of these components on the shaft is critical, again, simply adding a thicker washer will not work. The clip holding 2nd gear on the shaft will not seat into the groove. Many have a problem with the 2nd gear spinning against the spring clip (25) that it wasn't designed to do after this washer swap. I think it's fair to say that this clip is at LEAST as hard as the washer, and probably more-so. I have been back into the gears and motor with many many thousands of miles run with 2nd running against this clip, and the clip looked as good as the day I put it in.

On another note, I replaced the washer you spoke of (#17) with one exactly half it's thickness, and put another one between the middle drive gear (#30) and the spring clip (27) to keep the spacing the same but move 1st gear a bit closer to the 4th gear dogs. I would not recommend doing this. With the bike in 4th gear, there wasn't enough clearance between the 4th gear dogs and first gear lands and they would clash lightly... but enough to wipe both gears out that had been fixed once. I only made it last as long as I did by skipping 4th gear a lot.


Tod

[CavBird]

for some reason the site with thepics is having alot of issues so i moved them... here is the bolt

http://cavbirdie.blackapplehost.com/bike/100_4469.JPG

i did find alot of flakes on the xmsn cover including some 3/4 round threads
here is the xmsn... doesnt look like the dremel was done... not sure if i need to anything to the xmsn



i will try to get a better pic of the xmsn tomorrow... camera isnt working so was trying to use the built in web cam

seems i can only get one to show up... so i just put the link if you want to see the bolt

[CavBird]

i think its good???

ok camera seems to be toast so had to still use the web cam to try to get a pick...the areas between the gears are shinny in the right spots and the screws that hold the countershaft bearing in wasnt locktighted... so i think the dremel was done... just wasnt put back together well

here is the best pic i could get so far
anyone see any other probs till i close her back up?

[3Phase]

CavBird, the new picture link doesn't work, either, so I can't see it but I have a pretty good idea what happened.

You'll have to decide for yourself if you want to do any work, dremel or change the gears, or just clean everything up and put it all back together. These engines and transmissions are pretty tough but if you found flakes and threads you should check everything very carefully.

Forbidden

You don't have permission to access /bike/100_4469.JPG on this server.

I stand by my innitial statement.

Tod

Tod, I stand by my initial statement and I had almost exactly the same experience as you when I exchanged washer #17 for two half-thickness washers.

The gears are too close! Don't do it! <laughing>


I have two engine cases opened up at the moment and both drive axles will move side-to-side when bolt #28 is not torqued. One case contains a set of gears that was demolished when bolt #28 came loose while the engine was running, the other case contains a set of gears that is pretty much pristine for its age and in which bolt #28 has never come loose while the engine is running.


Regards,

Scott