Modern Vespa

There's a bunch of shredded drive belt strands jammed into my GTS clutch pulley from when it 'sploded' three weeks ago, and I'm having quite a time getting it cleared out of there. I've been able to use a pliers and scissors to get most of it out, but the remaining strands aren't cooperating, and I am looking for some ideas from more experienced Vespa fixxers on what I can, or should, do to get this mess dealt with.

Thanks in advance for any constructive ideas on getting Johnny's scooter back in the road.

have you considered taking the clutch nut off so you can remove the clutch from the whole assembly allowing easy sliding of the two halves of the pulley apart?


(hope that's the right name for that nut)

This was handy when dismantling the last larger scooter driven pulley / clutch assembly that I messed with:

https://www.amazon.com/gp/aw/d/B01GZVXX9W

I saw the nut, but want to be very cautious about taking the clutch apart further before asking the more knowledgeable members here about it. Having never done anything like this before, I was concerned that the clutch assembly may not be an easy thing to get back together.

My approach to these things is 'Look before you leap' rather than 'Take it apart and ask questions later'.

Take the thing into Northern Tool, find a socket that fits the nut. Take it home, hit it with an impact until the nut is off, take it completely apart, pop the cup that holds the spring, pull the pins and separate the two plates of the final drive. Clean it out, grease the F out of it, pump about half a tube of Malossi grease, or your favorite substitute, into the hole that didn't have a pin in it. Make sure the seals and o-rings are still intact and working. Put it back together. Get a couple of towels and push down on both sides of the fan until you see threads. Have someone start the nut about half a turn or a turn. Hit it with the impact. Pull the pulley halves apart, stick the belt in it as far as you can. Zip tie the belt as close to the pulley as you can, so it stays down in the pulley. Stick the clutch back on. Install the variator. hit the variator nut with the impact, cut the zip tie. Button it back up and you're done. That's about an hour.

Wow! Thanks! This is why I didn't want to use the trial-and-error method, and almost certainly screw it up worse than it already is.

Despite what you may have been told, primarily by sellers of the special tools, if you take it to any shop that isn't located under a tree where there is no power, the technician is going to use an impact wrench to remove and reinstall the variator and clutch in a belt service. When you read about variator or clutch nuts coming off, scroll up and you will likely read about someone using the special tools and a torque wrench.

I just watched Robot's video on rebuilding a GTS clutch that also had a shredded drive belt, with that, and along with the advice I've found here, I'll be able to get this thing rebuilt, but I'll have a bit of a wait while I order up some fresh grease seals and O-rings for the clutch.

I also now have a good excuse to visit some local pawn shops for an impact driver to add to my growing tool arsenal. Just yesterday, I found a small (1 1/2 ton) floor jack($75) that I needed to do my own oil and filter changes on our '16 MX-5 Miata.

When you reinstal the new belt you have to squeeze the upper and lower parts of the belt together so that you don't pinch the belt.

So if you wrap the new belt around the pulley in your picture and squeeze the belt togther you will force the sheaves apart slightly against the spring and maybe able to pull all the bits of old belt out.

motovista pretty much nailed it.

remember that the clutch nut goes on a specific way-- the small grooves/striations go *toward* the clutch (ie on the bottom). also, throw a drop of loctite on that sucker.

anyway, there's a bunch of different ways to tackle compressing the clutch. just don't use vice grips.

Over torquing is not much of a risk?

You'll need an extra set of hands but this seems the best place to start. Do the twist and squeeze to seperate the halves while someone clears out the debris.

I decided to buy a new impact driver from Harbor Freight for use in my GTS clutch repair, and got one for $45, though it's not the cordless kind because our Black and Decker battery packs for our weed whipper and electric drill etc., won't work with the HB impact driver, and would require us to purchase an HB compatible battery for an additional $75-$80. So the heck with that, and because the impact driver will only be used in our garage, the corded version isn't a problem.

The next 'issue' to rear it's ugly head, is that in the YouTube Robot video, the GTS clutch he disassembles has a 34mm nut, and uses a (duh!) 34mm socket on his impact driver, but the clutch nut on my '20 GTS 300 turns out to be much...much larger, at least 40mm, maybe 42mm, and I can't find a socket that big locally, I'll guess that I'll have to go look online for something like that.. hopefully.

I did find a 39mm socket at an O'Reilly Auto Parts store, bought it, but it's also STILL too small, but at least they said I could return it if it wouldn't work, which I will tomorrow.

That is one big-ass clutch nut...seen with the new 39mm socket atop it to show it's relative size.

I expect that I'll draft Trixie and her deft little hands to help with that part.

Put two paint/sharpe marks one on the nut and one on the housing so you can realign them when tightening the nut back up.

iirc it is a 46mm on my hpe. Had to order it.

You'll have to check with your O'Reilly but mine will loan a bunch of different specialized tools including oversized sockets.

.

The O'Reilly that I bought the 39mm socket from offered to 'rent' the socket to me for for $21, then bring it back after using it...and not only lose the $21, but the socket as well....or I could buy it for the same amount, $21, and keep it.

Try to figure THAT one out, 😜

Recommend a cheap caliper. My wife carries one to insure accuracy when on parts runs.

There's a 1-13/16" socket in my toolbox that was used for a clutch nut. Problem is, I don't remember which scooter it was. Anyway, that works out to a hair over 46mm. I bought it at an auto parts store; that size is used for a common axle nut I think. It does have a 3/4" drive so I had to get an adapter for my 1/2" wrenches.

Northern Tool has a 46mm socket, and in stock at at least some of their stores. https://www.northerntool.com/products/klutch-jumbo-socket-metric-3-4in-drive-12-pt-4145

Thanks for the link!

I had measured the nut at 1 13/16th, but as stupid as it sounds, had problems finding the metric conversion for that number.

We have a Tractor Supply store here, I might run over there and see if they might have an agricultural 46mm socket in stock, otherwise, I'll order one online and start the wait for delivery. I didn't see one available from Scooterwest.

Just a bit of advice: Buy a couple of adjustable jack stands as well. I would not trust my life on a small 1 1/2 ton floor jack.....

Thanks! I'm ahead of you on that point.

I'm admittedly not 'the sharpest knife in the drawer' when it comes to vehicular home maintenance and repair, but I have little desire to end up squished beneath a little Japanese sports car, or anything else for that matter, and will only be using the floor jack to lift the MX-5 high enough on both ends to get four, 3000 pound jack stands under it at specific raising points. I won't need to get my body under the car to position the jack stands once it's raised by the floor jack. It'll be very solidly, and safely supported.

I already had two jack stands, and bought two more, along with the floor jack, just for this job a couple days ago.

Thanks to my Vespa's transmission ailment, and my desire to perform an oil/filter change on our Miata, my specialized and general use tool and garage equipment collection has been impressively expanding over the past several weeks.

As long as it does what I need it to do, this $45 Harbor Freight impact driver is an amazing value, and it should come in handy quite a bit in the future.

It's a big, heavy thing, but who cares as long as it gets the job done, eh?

It's also worth spending the extra coin to get impact sockets over the normal ones that you use with hand ratchets or flex handles.

I maintain 6 cars in my family - my old truck, my wife's RAV4, a WRX and 3 Priuses. For just oil and filter changes, ramps are much easier than rolling out the 3 1/2 ton floor jack and stands. Just remember to always place at least one wheel chock at the back tire when on the ramps.

I just broke down a driven clutch this morning. It's a 2008 model, but same job. That 1 13/16 will be hard to find, but I got a 46mm Stanley Proto socket with a 1/2" drive off of Amazon.

Here's a pictorial, following Geo's description.

Now, we dismantle the pulley.

YOWZER!!

Thanks a HEAP for posting your images, tips, and procedure for dismantling that clutch, it'll help immensely!

Once everything has been thoroughly cleaned, here are the steps for reassembling the pulley:

Here's where my process varies slightly; I use a tool to compress the clutch instead of a buddy. It makes it easier to locate the flats on the pulley shaft and gives you all the time you need to thread the clutch nut back on.

Put some muscle into it and compress the pulley, have someone else untangle the broken threads, no need to dismantle the whole thing…

A local farm/ranch agriculture supply store to the rescue with a 1 13/16ths, 3/4 drive socket for that pesky clutch nut. Nothing like this was apparently available in any of the local chain auto parts stores, at least without special ordering and waiting days for it.

It may not be absolutely perfect, but it certainly does seem to fit that 46mm clutch nut quite well, so that's one more troublesome hurdle dealt with for this project.

I think it's quite funny to find a special tool for a Vespa at a farm/ranch store.

As I was checking out, I held up this massive, teacup-sized, socket and asked the nice lady if she could believe that it was needed to fit a Vespa scooter part?

I wonder what might be a locally available compatible grease instead of the Malossi stuff?

Also, do the two rubber grease gaskets and those red O-rings HAVE to be replaced as just a matter-of-course when re-assembling the clutch, or can they be cleaned and reused?

I suspect you could use any high temperature EP grease. I'm fond of the Malossi stuff because it seems to hold up well.

You can clean and re-use the O-rings as long as they're not distorted. Your bike is still quite young. I'd reuse the shaft seals as well. I'd consider replacement if they were a decade old or if the clutch assembly had been neglected for a while.

The unit I showed is out of an '08 with about 7800 miles on it. The O-rings were still round, springy, and still fit snugly in their grooves. The shaft seals were still pliable and not showing any signs of leakage.

Personally, I'm a fan of doing this job every time I replace the belt and rollers. It helps keep the whole CVT working smoothly and seems to improve longevity of the sliding sheave.

With the clutch mechanism off the scooter, you can also fit that giant nut into a vise and crank it on and off with a strap wrench like you'd use with an oil filter.

A pipe wrench will also git 'er done, but of course we ain't proud of that.

That's the answer on Yamaha Vinos and Suzuki Burgmans. Easier to wrap a Stillson around something you tolerate than something you love.

"Oooooh, Oooooooh, Oooooooh!"

(Pounds chest)

You got this!

That is not an impact socket (impact sockets are black). As large and thick as it is, you'll probably be fine. But standard sockets can shatter under the pressure from an impact wrench. Recommend wearing safety goggles at the least and a full face shield if you have one.