3rd Gear noise on a Lf200gy-5

[DDG1976]

Today on my way to work I noticed a gear noise in 3rd, quiet in all other gears. It reminds me of chain noise when the chain is too tight. I'm wondering if it is a sign of trans failure in my near future.

[FastDoc]

May not be a factor, but how's the oil level and condition? How many miles?

[forchetto]

To give us further clues, does it make a whining or a grinding noise?
Is it the same with a hot and cold engine?
Does it do it accelerating or decelerating, or both?.

At first it sounds like a worn gear or shaft bearing, but it could be something simpler as FastDoc has pointed out.

[DDG1976]

Bike has a little over 7000km on it, oil level is normal, and is due a change in few hundred km. It's an 08 model. The noise is more prevailant in the lower rpms (I think because the exhaust drowns it at higher rpms). It's a ch-ch-ch-ch-ch sound that gets faster with the rpms.

[czowner]

I don't want to be a bringer of doom but if it only affects 3rd gear I would suspect a broken gear tooth, I've been down this road with mine. Drop the oil and see if anything comes out, when I drained mine a whole gear tooth came out!
<a href="http://www.picturetrail.com/gallery/view?p=10&imgid=362783748" target="_blank">
Jonathan.

[SpudRider]

Originally Posted by czowner

...Drop the oil and see if anything comes out, when I drained mine a whole gear tooth came out!
<a href="http://www.picturetrail.com/gallery/view?p=10&imgid=362783748" target="_blank">
Jonathan.

Yikes! It certainly will not harm to change the oil a little early.

Spud

[DDG1976]

That's what I had planned, this weekend I'll change to oil out with AMS synthetic motorcycle oil and I'm going with a little heavier weight for summer. I will drain it through a fine screen and let you guys know what the oil (debris) looks like. If it is the end of my trans, I've pondered the idea of getting a two stroke 250 off ebay and making brackets to adapte it to my frame.

[DDG1976]

By the way, on the way home last night it didn't make any noise untill I got almost home, approx 10 miles.

[czowner]

Originally Posted by DDG1976

By the way, on the way home last night it didn't make any noise untill I got almost home, approx 10 miles.

AH! If the noise isn't a permanent fixture discount broken gear teeth.

Jonathan.

[DDG1976]

Would broken teeth be felt? As in slipping, or jerking? I'm hoping there is just some trash in there that a few oil changes will get rid of. The sound reminds me of a ring gear and pinion in a car that wasn't clearanced correctly. But not as much whining, or howling.

[katoranger]

Try an oil change and report back.

Allen

[czowner]

If it is broken teeth, and I doubt it is as the noise isn't permanent, it will feel rougher in the affected gear, and there'll be a pretty distinctive crunching sound as the broken bits mesh. One of my damaged gears had damage over 4 teeth and it still rode OK, if a little noisy!!

Jonathan.

[DDG1976]

Well I finally got around to changing the oil today. Nothing but oil came out the drain plug, but when I removed the screen to clean it, it had chunks of what looks like a gear on it and around it. Here's a pic, but it's a little blurry.

[forchetto]

It doesn't look good so far... :( There maybe more bits floating around the engine and inside the oil pump and oilways ready to wreak havoc if they get into the bearings or bore.

Rotate the gearbox using the back wheel or, better still, directly with the gearbox sprocket in the affected gear to feel for any regular rough spot that would indicate a damaged tooth. You'll have to tie the clutch lever to the bars to keep the engine disengaged from the gearbox to do this.