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View Full Version : Does belt wear = more noise?



sgtp
18th June 2012, 17:12
I have noticed when letting off the gas at high speeds that there is a sort of clattering sound that has not been there before. I looked over the scoot the other day and I think its coming from the transmission. My scooter has around 10,500km on the original drive belt, and my somewhat acruate measurement of the belt shows its only 1mm less than what it was new. So, what have you all noticed when your drive belts have started to wear? Is extra noise from the transmission normal when the belt starts to wear? I dont think this noise is from the engine as the noise is not constant.

Akzle
18th June 2012, 18:42
i'm assuming you do actually mean a scooter which generally runs something like: engine - centrifugal clutch - reduction box - wheel.

what you may be experiencing is worn return springs/pads on the clutch/throwout

although if the belt has stretched beyond service limit (the LENGTH of the belt is way more important than the width) then it need replacing as there's generally no adjustment in your drive/driven pulleys.

look in a service manual, or google for "v belt failure, diagnostics, signs of wear" it will show you cracks, glazing, wear patterns etc to look for. (not that this will help you here)

((edit)) "clattering noise" could be freeplay between shaft and pulleys, pinions/bearings etc. in general new noises pre-empt gear failures. diagnose and sort it out.

sgtp
18th June 2012, 20:29
Yeah, its your ordinary CVT with a v-belt. I really have not heard of v-belts stretching. Perhaps that occurs on the big scoots, but my Sachs is just a little 50. I paid close attn to it on the ride home tonight, and its combination of noises; clatter, oscillating/reverberating sounds. This scoot gets a pretty good workout though, riding two-up up the hills, etc, and Ive smelled the signs of a slipping(burning?) belt at times. The tires as well as the front rotor are at or nearing the end of their life, so I suspect perhaps the same is true for the belt....got some googling to do...

sgtp
18th August 2012, 13:28
Update:

An inspection of the rollers showed that each one has a flat spot, so I ordered new rollers and a new belt (which also started slipping). They just went in today, and my test ride didn't have any of the rattle/clattering sound, and have gained back a few more km/h as expected. All in all a simple fix, I just wasn't aware of the symptoms that occur when you get to this point of wear on these parts. Next up is some new rubber and this scoot is ready for another 10,000 kms:woohoo:

For those wondering how to get the variator nut off, most say to use an impact wrench, or fashion a strap around the variator to hold it still while you turn the nut. I did something a little different. I noticed some indention around the outside edge of the variator, so all I did was wedge a cheap hex wrench into the indention and let it come in contact with the hardened steel gear used by the started motor to turn the engine over. That held things stationary to turn the variator nut. The cheap hex wrench is made of soft metal so it took all the punishment. Its not the best method, but hey it worked for me....thought it was worth sharing...

Akzle
18th August 2012, 18:26
For those wondering how to get the variator nut off, most say to use an impact wrench, or fashion a strap around the variator to hold it still while you turn the nut.

good that the way you did it didn't cause damage, as it was likely to.

i generally use an oil-filter-strap wrench. (i seen em at repco for like 20 buck!) terminates to 1/2" so can hang off a breaker bar/ ratchet.

glad you got your wheel sorted though!