Gear change-down problem

[wjland]

I could not change down from 4th to third on my Sport 1100i on a ride last Saturday and had to get home in 4th and 5th. OK because I live in the country. I managed to get back down through the gears after a bit of fiddling back in the shed. I am not sure what I did to fix it and haven't test ridden it yet. Has anyone experienced anything similar and what is entailed in fixing the problem?
Bill

 

[GTM®]

Bill, does the shifter seem to hang and need manual force to get it to move? If so, it's a broken or near failing shift return spring. The gearbox would have to be removed to get to it, as it resides under the end plate.

 

[guzzibob]

Doesn't sound like the shifter return spring problem I'm used to hearing about, where you normally just have to manually pull the shifter up each time with your toe in order to reindent, cause the spring is busted & won't do it. Unless the busted bit of spring has gone & jammed itself somewhere. At least that is the way it usually is in the older gearboxes. Something different & bizarrely unusual happened in my 1000S gearbox, but the symptom there was you could go up in gear, but never down, so once you were in 5th-that was it, you stayed there. Clearly not your problem.

Sure there is not an issue with the linkages external to the gearbox? Be sure to take a close look.

 

[notasweetman]

Hi, guys,
I've had this problem and we think we've found the reason. My Stelvio has been in the shop (under warranty, thank goodness!) for the last week and I should be able to pick it up later today.

Over the last 2-3000 miles I've occasionally been unable to change down just as you describe, mostly from 4th downwards, but then have been able to tease the thing into neutral later, after which the problem generally went away for a while. It felt like treading the pedal onto something solid, there was no slack at all. I almost convinced myself that I was making it up between having the problem, but it would reoccur a few hundred miles later.

Turns out that there's a pin (no.11 on my gearbox diagram) that locates onto the selector spring. The pin is screwed into the gear casing and it had partially unscrewed itself from vibration, enough to stop the selector. The mechanic said the pin clearly had screwed itself in and out over time, resulting in the problem being intermittent.

I hope this might help your diagnosis, but alas it needs a full gearbox strip to determine. Good luck!

 

[notasweetman]

The pin has a hex collar that caught in the pre-selector when partially unscrewed, jamming downshifts. The mechanic showed me the burr on the collar where I'd tried downshifting. Apparently the pin had only unscrewed a little, and there is no possibility of its coming out altogether, but it was enough to interfere.

Once found it was simple enough to tighten the pin with some threadlock and put the bike back together! The only problem was, being a Stelvio, it took 2 days to get the thing apart and 2 more to put it all together. The mechanic said it's like peeling an onion, it's got so many bits bolted to other bits, etc. Luckily it's still in warranty.

I had an Aprilia Tuono R as a loan bike for the week. Great bike, fast, focussed, big trouble keeping the front wheel down. But cramped, thirsty and I couldn't wait to get the Stelvio back. And the Guzzi gearbox is a joy by comparison - now it works!