Clutch not fully releasing - and shifting problem

[Lucky Phil]

Pulled the pre-selector off the LeMans (on right) and off the spare transmission (on left).

 

 

The LeMans preselector goes through all the gears on the bench, up and down.  So I'm really sure what I would adjust.

 

The spare also goes through all the gears, but it feels even tighter and crisper. And the spare has a metal banana on it.  I think I've seen something about this being standard on the 2004 bikes, and that there was an upgrade kit available for the earlier bikes.  So... is there any reason I shouldn't just put the newer preselector in?

I would try the spare but for the purposes of comparison and information check the differences between the two. As you shift through the gear selections on the bench look at the minimum clearance on the shift pawl arm to the smaller eccentric adjuster shown ctr left on the photo. Make sure it's at least 0.030". 0.040" should be ok as well. Next select the gears one by one while using your fingers to provide a little resistance to the selector wheels and note when the selector wheel drops into the detent whether or not the input arm has contacted the large adjustable stop. You will probably find that in some gears it will hit the stop in one direction befor the selector wheel detents ( meaning the detent arm,roller and spring are actually doing the work of pulling the gear into final mesh, not your foot on the lever) and will be off the stop in the other direction when it detents and if you continue to move the shift lever input arm it will actually start to move the selector wheel back in the direction of de selecting that gear. You need to provide resitance to the selector wheels thought as you do this so they dont snap into the selected position. so you can see whats going on.

If there is a big difference between the gears selected positions after this check then adjust the main stop eccentric so that it selects the gears fully with no or minimal overtravel ( or tendency to try and de select the gear). It is very sensative and fiddly which is why you shouldnt do it on the bike. It will probably be a compromise which is why on my other trans I added some weld to the stops to eliminate the compromise.

The other reason you MAY have 3rd to 4th issues is that the selector sleeve and/or gear dogs are worn and a little rounded off from missed shifts. When these are worn and have rounded corners then they dont "grab" the next gear as effectivley early in the shift phase and its harder to get a clean shift.

 

Ciao     

[Scud]

Thanks Phil - 

 

First the good news. I put the spare selector on and it's flawless. Just went for great little night ride and didn't miss even one shift. This includes 3>4 under hard acceleration around 7,000 RPM. Oh happy me!

 

Then the "hope it doesn't bite me later" news... I didn't notice till after I had everything together that the metal bushing (in top left hole of RH selector above) stayed with the spare transmission. So it's all back together with no bushing on the top corner. I assume this is mostly to help with alignment when installing the pre-selector, but if I develop a leak there, at least I'll know what to do.

 

And onto the learning curve. I did compare the two units carefully as you described, then adjusted the eccentric. It was loose beyond any feeler gauge, so I think that was the problem - and that it could have been fixed by the adjustment. But when I saw that the spare had the upgrade, I just had to install it.

[Lucky Phil]

Thanks Phil - 

 

First the good news. I put the spare selector on and it's flawless. Just went for great little night ride and didn't miss even one shift. This includes 3>4 under hard acceleration around 7,000 RPM. Oh happy me!

 

Then the "hope it doesn't bite me later" news... I didn't notice till after I had everything together that the metal bushing (in top left hole of RH selector above) stayed with the spare transmission. So it's all back together with no bushing on the top corner. I assume this is mostly to help with alignment when installing the pre-selector, but if I develop a leak there, at least I'll know what to do.

 

And onto the learning curve. I did compare the two unites carefully as you described, then adjusted the eccentric. It was loose beyond any feeler gauge, so I think that was the problem - and that it could have been fixed by the adjustment. But when I saw that the spare had the upgrade, I just had to install it.

Which eccentric was loose Scud, the small one? Glad you got it sorted and the info is valuable. I would still pull the cover and fit the bush though, but thats just me.

 

Ciao

[Chuck]

I'd say definitely refit the bush..it's used as a dowel for location.

all you have to do is drain the oil yet again..

[Scud]

 

Which eccentric was loose Scud, the small one? Glad you got it sorted and the info is valuable. I would still pull the cover and fit the bush though, but thats just me.

 

Ciao

 

 

 

I'd say definitely refit the bush..it's used as a dowel for location.

all you have to do is drain the oil yet again..

 

 

The clearance to the small eccentric was loose. Thinking back on it, it's probably my fault. When I initially did the shift-improvement on this bike, it was the first time I had ever opened any transmission - so it's not a surprise that I didn't get it right the first time. Then I just assumed all my problems were due to the clutch not being right.

 

I did't notice the lack of bushing till I went to put the cover back on the spare trans. Two bushings. Wouldn't fit. So yeah... I'll go soak both bushings in some penetrating fluid and see if I can remove one easily.  Then drain the oil, remove the starter, pop the cover (yet again).  I might sneak in a few more miles before I do it though, cuz I am so happy on my red bike now - like this little fellow.

 

 

Do you know why Moto Guzzi added the metal banana? What's it supposed to do? Cheese-head wants to know. 

[footgoose]

"Do you know why Moto Guzzi added the metal banana? What's it supposed to do? Cheese-head wants to know.  :cheese:"

 

the banana looks like maybe a better way to reduce lateral flex on those gears than just cir-clips. ?? isn't there is a sprung nipple for the neutral switch under one side pushing up?

[Lucky Phil]

 

 

Which eccentric was loose Scud, the small one? Glad you got it sorted and the info is valuable. I would still pull the cover and fit the bush though, but thats just me.

 

Ciao

 

 

 

I'd say definitely refit the bush..it's used as a dowel for location.

all you have to do is drain the oil yet again..

 

 

The clearance to the small eccentric was loose. Thinking back on it, it's probably my fault. When I initially did the shift-improvement on this bike, it was the first time I had ever opened any transmission - so it's not a surprise that I didn't get it right the first time. Then I just assumed all my problems were due to the clutch not being right.

 

I did't notice the lack of bushing till I went to put the cover back on the spare trans. Two bushings. Wouldn't fit. So yeah... I'll go soak both bushings in some penetrating fluid and see if I can remove one easily.  Then drain the oil, remove the starter, pop the cover (yet again).  I might sneak in a few more miles before I do it though, cuz I am so happy on my red bike now - like this little fellow.

 

 

Do you know why Moto Guzzi added the metal banana? What's it supposed to do? Cheese-head wants to know. 

 

Oh OK, the banana link seems to add some support to prevent the selector wheel posts from flexing. I fitted the mod kit to mine which came with all the required parts. Still cant imagine those posts flexing though, I suspect the Guzzi flywheel man looked at the mechanism and figured it was underweigh and corrected it.)

 

Ciao  

[czakky]

I suspect the guzzi flywheel man figures a lot of things are "under weight"....

 

Carry on just here for comical relief.

[Scud]

I don't like re-work. But the bushing is back in and I'm glad I did it.

 

Thanks again for the help solving this problem. The bike is much more enjoyable now because of all you fine gentlemen.