Transmission Problem

Riding back from a successful MOT this morning, my 850T developed a sudden and dramatic sounding transmission noise.

At this stage I’m not sure if it is the clutch or the gearbox, and wondered if anyone has any ideas out there, before I start investigations.Â

The symptoms are:
With the engine running, there is no noise until the clutch lever is pulled. The noise is a grating noise akin to gears not being fully engaged. The gears can be selected normally, but when I try to release the clutch the grating noise gets much worse, too dramatic to enable drive to be taken up.

Any thoughts much appreciated.

it could just be the clutch cable is in need of adjustment, or the clutch pushrod thrust bearing needs replacing, or it could be the clutch on its way out, try the easy bits,adjust cable first then if no difference renew thrust bearing, before spending money on new clutch plates etc.
is the gear change lever set up right ? make sure the lever is not jamming on the down pipe, very unlikely in this case but should be checked,

When the plates on my 850T started to disintegrate I got lots of slip but no grating noise, so I doubt it’s that. Maybe the teeth on the driven plate are worn. If you decide to go in there, it’s fairly straightforward and you only need one special tool for centering the plates on the crankshaft. It’s worth replacing springs at the same time and you can give the UJ a bath while you’re at it. Cable / arm adjustment is definitely worth looking at first though.

Hazard a guess it’s thrust bearing rollers breaking up. Good news it’s removable without taking gearbox out. But swing arm may have to come off to get access.Â

Thanks for those suggestions guys. I haven’t dived in yet, but after looking again at it at home, it sounds/feels very ‘clutchy’. The noise is emanating from the clutch area, rather than the gearbox. The gearbox is selecting all gears as normal. The noise changes in tone as soon as I pull the lever, it gets worse basically.Â

Could be clutch plates then!

Plus one for thrust bearing. Noise can appear to be from clutch rather than rear of gearbox due to tortured pushrod transferring noise to clutch! Well that’s what happened to one of mine.

My money’s on it being thrust-bearing related.

Thanks Guys,

Now that I’ve removed the thrust bearing it looks to be in good shape, so I think I’m back to the clutch again.

Mr Roper’s ‘crabbing’ Â method looks favourite.

Didn’t Ian Dunmore have exactly this happen to him on Friday?