Can't figure out chain case whine

[mdkuni]

For a couple seasons I have been trying to chase down why my chain case is whining. It it is a very loud whine that over powers the sound of the motor/exhaust. The case also gets so hot after a ride that you can not even touch it.

Before the start of the season, I replaced all of the chain case bearings, jackshaft bearing, speedo bearing, and the chain. This made no difference.

I played with the chain tension while on the stand. I loosened the chain quite a bit and I also snugged it up. No change in either direction.

Does anyone have any ideas on what it could be?

 

[darv]

What kind of oil are you using

 

[mdkuni]

Yamaha chain case oil. 8.5oz

 

[Apex18]

What do you mean by snugging up the chain? I hope you mean finger-tight & then backing it off 1/4 turn?

 

[mdkuni]

What do you mean by snugging up the chain? I hope you mean finger-tight & then backing it off 1/4 turn?

Yes I tried that as well as tightening it finger tight and not backing off. I am confident this is not a chain tightness issue as no matter what direction I went there was no change.

 

[blue er]

did you change the bearings in the gears? i believe there is a needle bearing in between the lower gears

 

[APEX 06]

Is your case vent open, check for a bent shaft.

 

[mdkuni]

Drive shaft is new this year. I did not replace the bearing in the gear.

How can I verify the vent in the dipstick other than whiping it down with a rag?

 

[Dano]

Is the replaced chain OEM? Gears all OEM? I've seen failures due to different chain/gear makes with slightly different pitches.

I think you also need to be careful with track tension with the ZX-2 suspension. I believe the track tightens up as this suspension compresses down which can stress drive axle.

Dan

 

[mdkuni]

Gears and chain are OEM. Track tension is good.

Found the small middle gear that the chain rides on was chewed up bad. Also when I pulled the bottom gear one of the pins in the bearing came out. I found a used bottom and middle gear and installed.

Chain case temp seems to be down and the whine is gone on accel. I am still getting a whine on decel. This happens before you hear the whine from the clutch.

Any ideas on what it could be?

 

[thor452]

just going out on a limb here but maybe top gear? lol

 

[Rich Kay]

Just a shot in the dark....But what about your brake?... is it running "free" ? Anything that is not happy there could be making your heat and maybe even the odd sound?? Just a thought!

 

[mdkuni]

Top gear had some groves and I could not find a replacement today. I will be replacing it. Seems strange that it would not make any noise on accel but will on decel.

I will try testing with the brake off as well.

 

[blue er]

decel i would say gear wear issue, it also may have a funny wear pattern on the chain due to bads gears, the whine may go away with some miles