Horrible trans grinding noise

[jawnski]

I have a terrible sound coming from my old faithful 1980 XS11g. I have 55k miles on it. I am hoping someone here has had the same issue or can give me some pointers. I’m sad because my bike is sick and I’ll have to drive my stupid car.

It seems the sound is coming from the transmission. When the bike is driven for 3 or 4 miles, the sound goes away. It is a LOUD clicking/grinding sound. It sounds to me like, when you try to put your bike in gear without pulling in the clutch you hear the gears grinding. It does not matter if the clutch is engaged or not. The grinding sound is there.

I made a recording but it’s not the best. Click here (580k) http://members.tripod.com/jawnspages...sion_noise.htm

Thanks for everything. I love this website.

John Richau
Fresno, CA.

[Ken Talbot]

When was the last time you adjusted the cam chain slack adjuster? If loose, the camchain can make an amazing amount of scary noise...

[Bud Manley]

Hell it sounds great to me. Mine has a sort of high pitched whine when riding and a loud clunk when I put it in gear.

[jawnski]

Yes, I adjusted the cam chain. At first I thought it was the chain slapping around then the valves but I noticed that the sound went away when I put it in gear after a few miles of rding. I'm afraid to ride it now because it sounds so bad...like something is ready to expode.

[Ken Talbot]

I would still go back and reconfirm the cam chain. Even with following the procedure exactly (i.e. getting the correct timing mark, turning the correct direction, etc) I've still had one slip - thought it was going to blow up it was so nasty!

Another question - how long has it been making this noise?

[jawnski]

Thanks Ken, I'll re-adjust it tomorrow and see if that does the trick.

It started a two days ago. I checked the middle gear oil and it was fine. I bought the bike with 50k miles on it and now it's 55k. I know the previous owner but he's out of the state right now. He took good care of it mechanically.

You know, it is very difficult to tell exactly where the noise is coming from. I guessed the transmission because when I am at a stop and put it into first, it goes away.

Thanks again.

[skids]

The plunger for the cam chaion adjuster can get burrs on it from the stopper bolt. I think that it could prevent it from adjusting to tighten the chain.

There is a bearing in the clutch "star plate" that might be worth checking.

There have been many accounts of the HiVo chain (main internal drive chain) slapping around when the engine is running rough, like at idle when she is about ready to stop running. This chain is not adjustable to my knowledge. The slapping is near the transmission (if it occurs). Some people have actually had the chain slip while riding.

You don't want to run the middle gear oil low because the gears can lock up while you are riding. Check it and change it if you never have. Look for metal.

[uk1.1s]

Grinding away

Haven't had time to listen to the sound file, but my gearbox started to grind itself apart when the little circlip that holds fifth gear onto the end of the shaft gave up the ghost and allowed the gear pinion to contact the inside of the cases.

Only happened if I tried to shift from 4th to 5th. Of course on the first look the gear was back in place and it was impossible to diagnose!!

Could be that one of the gears is suffering the same fate and popping back into place after a while of riding.

Hope not for your sake as it was a hell of a job fixing after finally diagnosing (don't ask me how many engine rebuilds!).

Try the cam chain theory first...... but just something to bear in mind

Good luck - Graham

[jawnski]

Thanks Ken, Skids and Graham.

IT WORKED!!! But now…….



This was the third time I adjusted the timing chain in as many days. This time I backed the adjuster bolt way out and then back in. The only problem now is that it seems to be stripped. I cannot tighten either the lock nut or adjuster bolt. It also seems there is a gasket/washer that is coming apart.

http://members.tripod.com/jawnspages/yamaha.htm


Now the question is; can I remove the cam chain adjuster without removing the chain? Does it just slip in and out. My neighbor can rethread the bolt. I also see some timing chain adjusters on ebay.

[strom]

No worries mate, just undo the two allen bolts (I think) that hold the adjuster. Top and bottom. And take it out. And a word of caution: tighten (not too much) the retaining screw (the one on the side) first, so the spring doesnt launch the whole thing into a place u dont want it to be.
OK, once again in order:

1. Tighten (by hand is enough) the retaining bolt on the side. Like when the chain is adjusted.
2. Undo the two bolts that hold the adjuster assy.
3. take it out
4. undo the retaining bolt and BE CAREFUL, that spring is quite strong.
5. dissasemble everything you see
6. repair the threads, replace the bolt, whatever.
7. CLEAN it REAL good. Dont want any metal shavings in the crankcase. Use an air compressor. Not the gas station one.
8. grease it up a bit so it doesn't seize, asseble and RIDE!

I overtightened it too and I had to make a new (larger) thread into the assy. case. It works, no biggie. Just seal it up back real nice. And if you're replacing the bolt, check the tip of the bolt. I think you might want to grind it a bit into a spike or sth so it holds the adjuster better. I didn't do it, but it was done before.

LP

PS: When I ride, I hear a pinging noise bout 2 min into the ride... pings a few times quite loud (like banging on one of the crankcase covers.. a bit plastic maybe), but when I ride a bit more, it stops. Any ideas?

[Ken Talbot]

Glad it turned out to be the cam chain, John - the alternatives could be really scary. As Strom notes, a small helicoil should set you straight....