View Full Version : Grinding sound from transmission?
minieggroll
05-16-2012, 02:43 PM
Hello,
So while I'm in 2nd or 3rd gear I heard kind of a grinding noise coming from somewhere in the transmission/gearbox. I haven't been losing any power or anything, just a rattling sound during lower rev range. My drivechain has correct tension and I'm not sure what it could be.
I'm wondering if my clutch isn't fully engaged when I'm riding. My clutch disengages fully with about an inch before I fully squeeze the clutch handle and engages very close to the fully released handle.
jonathan180iq
05-16-2012, 03:10 PM
A grinding of the gears shouldn't come from a clutch issue, even if it's a little off.
Change your oil pronto and see what comes out of it.
Aside form the occasional clunk when going into gear, you shouldn't have any idea what's going on in there.
minieggroll
05-16-2012, 03:23 PM
I changed my oil in February though, only put about 1100 miles on it since then?
Water Warrior 2
05-16-2012, 04:03 PM
Folks have been fooled by sounds. Heard of this before. It was actually the front sprocket reaching it's serviceable life and the chain was trying to climb up the teeth. Pull the front sprocket cover for a visual inspection of the sprocket. That might be the problem.
jonathan180iq
05-16-2012, 05:31 PM
I changed my oil in February though, only put about 1100 miles on it since then?
It's not because you did the oil wrong or anything. You are draining the oil to see if there are metal shavings in it. If there are, you are about to have some serious issues. (We're talking flakes and stuff. Micro shavings aren't that big of a deal, depending on how old the bike is. But if you're getting real grinding and clunking, you'll be able to see evidence of it.) And oil change is only going to cost you like $10. It's worth it just to check and be sure.
WW made a good suggestion. Give the whole bike a once over and make sure you aren't hearing something else. There are also vibration resonance pitches. It's possible that at those speeds, between 3rd and 4th gear, you are reaching a magic butter spot that is making something rattle that isn't in the case.
If you have a bike lift or some tall-enough wood stands, get the bike up to those speeds while stationary and see what happens.... you might want to have someone with you when you do this for safety's sake ;)
Water Warrior 2
05-17-2012, 03:56 AM
Do you have a windshield??
minieggroll
05-17-2012, 05:49 PM
After more observation, it seems the sound occurs when I left off the throttle all the way.
It might sound like my chain is skipping links and my front sprocket is wearing. I also am wondering how to adjust the clutch handle/cable to make it have more slack and require more squeeze of the clutch handle before it disengages.
@WaterWarrior. Yes I have a windshield, but I made sure that rattling wasn't coming from it.
mrlmd1
05-17-2012, 06:43 PM
I also am wondering how to adjust the clutch handle/cable to make it have more slack and require more squeeze of the clutch handle before it disengages.
.
Don't do that. There should be very little slack in that cable before the clutch disengages, You are going to mess it up so it never disengages completely.
5th_bike
05-18-2012, 12:28 AM
[...] how to adjust the clutch handle/cable to make it have more slack and require more squeeze of the clutch handle before it disengages.
Work the rubber off the handle bar end of the clutch cable and slide it down the cable an inch or two. Unscrew the large round ribbed locknut a bit (say 1.5-2 turns), while keeping the adjuster bolt it sits on stationary. Then screw the adjuster bolt into the handlebar 1.5-2 turns (the big locknut should turn along with it). Then, tighten the big locknut against the handlebar (less than 1/4 turn) while keeping the adjuster bolt stationary. Now, the cable has a bit more slack. Replace rubber.
PS the maintenance manual says that the clutch cable should have so much slack that the clutch lever should be flopping around freely (without even pulling the cable at all) 0.4-0.6 inch (10-15 mm) measured at the end of the clutch lever, so aim for that. It's called "Clutch lever play", p.2-9.
minieggroll
05-21-2012, 09:59 AM
Thanks 5th bike for your advice. After some adjustment with the clutch and tension of the chain, I think the sounds gotten a lot quieter. Appreciate the help!
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