Modern Vespa

Hey there! I just pulled my clutch bell off for a belt replacement. It was a pain- stuck as heck. Now, trying to get it back on, it won't go. Gets stuck at the spline. Do I need to replace it? Not an expert but don't see damage to the bell or spline?

Bell

Sticks here. Won't go pat this.

Mine has always been difficult to put on and take off. The scooter now has 50K miles on it. Why some tend to stick while other tend to slide on and off I have no idea.

I use a three leg puller to get it off. To get it back on I use a stack of washers and tighten bolt until it bottoms out. Then I add more washers and repeat till the bell is fully seated.

Maybe you should clean the spline grooves on both parts very thoroughly with a screw driver blade. One groove at a time to get any corrosion out. Then check to be sure there isn't a distorted tooth. Follow up with some WD40 on the mating splines using a tooth pick and a rag. Then wipe it all off before you assemble. That will give the splines their best chance at a smooth, normal fit.

Bill

That worked!! It may be hard to take off again next time, but it's on there and I think seated well.

I love MV! Thanks again!

What I do, is mark both parts, in one spot, before taking it off, so I can Aline them together at the same spot, when I reinstall them....

I used a 2 leg puller on mine today and it was still extremely difficult to remove. In the end I used a rattle gun on the puller bolt. It slowly came loose but fought the whole way. I also tried to clean the splines and replace the bell. No way is it going back on smoothly. I have still to get a belt etc so not refitting yet. Is a small amount of grease wise here? I know the clutch would not appeaciate grease but it is protected by the sleeve.

LX150 27,000 km. Don

I would say that a very light coat of copper anti seize grease is ok. Rub it thin because sliding the pieces together will potentially plow the grease off and into a small lump.

My bell slides right off so I would be worried if it was tight like yours.

Bill

I use bearing grease that does not run when hot on all the shafts and splines. I also use degreasing wipes on the pulley surfaces.

I agree should not be so tight on or off.

John

Rub the splines/grooves lightly with some wet'n'dry to remove any rust or debris.......and then clean off with brake cleaner or similar.

I use a very light smeer of white grease when re-assembling to aid slipping the clutch back onto the splines.

On Ivana Tinkle's LX a new clutch bell was the only answer. No matter how much I scraped and filed, the original bell was far too tight on the splines.

Rubber Hammer?

Rubber Hammer?

A rubber hammer wouldn't have touched it. I didn't want to have the same aggro in a few month's time, so just installed a new bell.

Some of us are just gluttons for punishment.

Thank you all for your posts. This is what I found on my et4 leader 125 engine today. I pulled the bell off with a makeshift puller (pic), then, the bell didn't go back on, even after cleaning. Then I flipped the bell upside down and easily slid it onto the shaft by its other end! - so it appeared, that the part of the splines that are tight are not engaging with the shaft in this way. It is very difficult to see the difference between the splines on both ends of the bell's barrel hole, so I filed lightly the tops of the splines on the though end, and the bell felt easier a bit, then (see pic), I covered the spline grooves with the marker ar tried it on again and it showed the scratches in the grooves, while spline tops were untouched. So again, I filed each groove lightly with a metal file at about 5 degree angle to the spline's horizontal plane. Bel now fits snugly, and comes off pulled by hand. My theory of what happened here: the splines on the shaft are shorter that the splines on the bell. It allows putting the bell on in dirty road conditions - the dirt will collect in the recessions on both ends of the spline and will not alter the length of the stack. But at the same time it happens, that the inner ridge of the bell spline rams into the edge of the shaft's groove at 45 degree angle. I guess that in case the shaft bolt is overtightened, affected by heating and cooling cycles, those few millimeters of the bell spline that hangs over the shaft's groove, get compressed and get out of shape by less than 10 microns, that's absolutely perfectly enough to stick the bell in place. Lubrication may not help here, best is not to overtighten the bolt using a new bolt every time or using old one with Loctite blue. Btw, no tapping on the shaft even with rubber mallet! The long arm makes huge leverage that may shatter bearings!


the puller

spline ridge

I had a similar problem getting mine off - but that was due to a bit too much loctite (which got into the splines).

Harbor Freight sells a very inexpensive set of three-arm gear pullers that make short work of clutch bell and variator removal.

You can see how the clutch axle has a countersink in its center - that's there to help center removal tools like the gear puller.