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Gear noise?

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Vincenzo

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Hi everyone, I bought a used C650 Sport with 40,000 km on the clock; it now has 50,000 km. There is a noise plaguing me that I haven't managed to fix yet. I’ve replaced all the CVT components, the drive chain, and all the rear wheel bearings—the only thing I haven't touched is the transmission gears (though I did change the oil, of course). This screeching sound is very noticeable at constant speeds, peaking at 60 km/h. When testing it on the center stand, the sound comes from the left side, right where the gearbox housing is located; the noise disappears when the CVT is removed. Has anyone else dealt with this issue? How did you solve it? Thanks a lot for your help.
 
I agree this is not a normal sound but unfortunately I have no suggestions, not experienced this. Since you've already put on 10K kms, perhaps it is not harmful. Or did it just start making the noise recently? Maybe change the drivebelt?
 
Ceesie76 said:
Concordo sul fatto che non sia un rumore normale, ma purtroppo non ho suggerimenti, non ho mai avuto un'esperienza simile. Visto che hai già percorso 10.000 km, forse non è dannoso. Oppure ha iniziato a fare rumore solo di recente? Magari potresti cambiare la cinghia di trasmissione?
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Ho già sostituito la cinghia, il variatore, la frizione, la campana della frizione e la puleggia secondaria, ma non è cambiato nulla; faceva già questo rumore prima. Funziona bene, ma è dannatamente fastidioso quando indosso un casco aperto. Il rumore dipende dalla velocità piuttosto che dai giri del motore; si sente un po' nel video, ma dal vivo è molto più forte. Grazie comunque per il tuo contributo.
 
Looks like root bearing gone bad on either input or output shaft, there is also an oiling system that should be checked (perhaps it was compromised) - I think it is on the primary, with a duct going into the shaft center.
 
Vincenzo said:
Hi everyone, I bought a used C650 Sport with 40,000 km on the clock; it now has 50,000 km. There is a noise plaguing me that I haven't managed to fix yet. I’ve replaced all the CVT components, the drive chain, and all the rear wheel bearings—the only thing I haven't touched is the transmission gears (though I did change the oil, of course). This screeching sound is very noticeable at constant speeds, peaking at 60 km/h. When testing it on the center stand, the sound comes from the left side, right where the gearbox housing is located; the noise disappears when the CVT is removed. Has anyone else dealt with this issue? How did you solve it? Thanks a lot for your help.
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Hi,
2013 C660 GT with a similar noise but since I replaced the timing chain tensioner with an hydraulic one the sound is less. Not a BMW OEM part but with a KYMKO one that was cheaper. I still need to do a new CVT belt though. I also fitted a Malossi CVT Variaror kit and what a difference it makes in the riding experience. Very nice.
 
RollaCosta said:
Sembra che il cuscinetto di base sia danneggiato sull'albero di ingresso o di uscita; inoltre, andrebbe controllato il sistema di lubrificazione (forse è compromesso): credo si trovi sull'albero primario, con un condotto che entra al centro dell'albero.
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Ciao, grazie per la risposta. Non si sente alcun rumore quando si smonta il cambio CVT, quindi potrebbe essere il cuscinetto dell'albero intermedio. Perché hai menzionato la pompa dell'olio? Senti qualche rumore insolito?
 
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