Modern Vespa

I noticed that the right rear shock on my GTS 300 is not connected. Can this just happen or did the service center screw something up?

Not knowing anything else, assuming it's an 8-year old scooter it "just happened".

Had my 2nd or third Maintenance last summer whichever is the expense one. Got a flat at the end of last year. Towed bike in a month or so ago to have both the rear and front tires replaced. I don’t hit potholes and I pretty much baby my scooter. I took a peek under today as I was contemplating whether to adjust the preload for 2 up and found the right side like that. I’m assuming something could have happened during the rear wheel replacement but I’m probably crap out of luck convincing the ship it was their fault. Just checking if this is known to happen.

my guess is the mechanic got interrupted (eg phone call) after sticking the nut on but before tightening it. came back, saw the nut was there and assumed he had already tightened it.

Question: is the nut still on there?

I just went to check mine. The whole shock is missing!

Well, if you had one I’d be concerned!

Everyone who reads this post will go and check if the bolt is missing ... Shocking.

There is no way that could happen if the service centre followed the correct procedure !

I have removed the rear wheel in order to change tyres or repair a flat twice.
The shock lower mount is tricky to remove and replace.
Once it is on there is a large washer and nut to keep it in position.
The nut needs to be torqued and this is all in the workshop procedure.

This suggests scary scenarios of inexperienced mechanics or worse ...

If it was put together properly last summer it's highly unlikely that it would have lost the nut and washer. I've never seen that happen on any bike I've owned. It's not your neglect or bad operation, it's their sloppy work.

Actually, it's just as much the owners fault too and he is supposed to check the condition of his or her bike regualarly. Sorry, not trying to beat down on the op but they have to familiarise themselves with the bike and make sure it's safe before riding. It's their responsibility. I always check my bike over weekly for this sort of thing, loose calipers, lights, brakes, tyres etc etc. I have to say though that this is without doubt as a result a sloppy (dangerous) service tech work. If torqued correctly those bolts don't work loose. They are nyloc nuts and they don't come loose.

The majority of scooter owners think that they are so simple that they do not have to do any checks, so much will those who do the maintenance think about it; but they are not, they are as complex as a motorcycle or a car.
I still check the levels every now and then (and other things) both on my car and on my scooter because the assistance is capable but the bad day happens to the mechanic on duty. :?

Looks to me, it's been put on and done up... It's the bottom shock bush that's let go.. the bush still looks bolted into place.

Exactly.

Lol following correct procedures in any work anywhere requires people working on anything doing the right thing always, we are human and thereby flawed. We get distracted, we get complacent, we get lazy, loose focus etc
Sadly the work ethic in many places and professions has gone to pastures.

Murphy's Laws are an example of this ...

Ive had that happen once. The mechanic got distracted and forgot to tighten up the nut. Buy a washer and a nut and get busy.

Nothing to do with the nut. As above (waves at Cheeky!) it's the bushing that's failed.

I don't think that's a separate part - a new shock may be in order.

Cant one just replace the bushing, maybe put a Clauss bushing and put a new bolt, washer and a nut. Or does one only replace the upper bushings.

One might be tempted to DIY it (there are no replacement bushings available AFAIK) - but a new shock is the answer.

I suppose it's possible the tech levered it off, as it's quite a muscle-developer to get that shock off the exhaust carrier if you don't get it 'just right', but it doesn't look like that to me.

I've never seen the bottom bushing replaced, only the top. Just checked my original rears (sitting in a box next to me 'cause I had replaced with SIP shocks) and the bushing in the bottom doesn't slide out. But maybe it could be tapped out with a suitable sized socket and a hammer or something, but then don't know what would replace it

But cheeky, there's a massive washer that holds the shock and bushing in place. If the bushing lets go the shock would not come off. The shock nut and washer would still be torqued against the bushing and metal insert and the nut and washer would hold everything in place no matter what. If you look at the picture it's clear the nut and washer are missing completely and that will cause the bushing to break away from the shock due to the forces that will be exerted. If the bushing is then unsupported/torqued it can't do it's job and will break as the shock tries to rip itself sideways as well as up and down. Pretty sure this is down to the nut coming off or not being present in the first place. If the nut is not torqued correctly or indeed not put on, the rubber insert will always work loose and break company with the shock.

However, it will be interesting to hear from Mr Bruno to see exactly what the situation is.

There is a nut and washer, but could the shock come over it? I'm thinking maybe as if the nut was missing I doubt the bushing would come out of the shock, as they are hard to press in and out.

We need the original poster to move the shock and then we would know.

Yes we need Bruno to come back with more info. Having just looked at my GTS, I don't think the shock would go over the washer. The washer almost completely matches the size of the inserted bush circumference and the hole in the shock where it all lives. My hat is off to you if you are right though...lol.

On my 2010 GTS, the washer has a smaller diameter than the bushing, by about 2mm. The bushing is glued in, surely? Maybe a not-so-bright tech heated it up to help force it off the stud.

Like many other bushings that are used in automobiles, this bushing is also pressed into the shock. For it have gotten out of the shock is very weird. pressing a bushing into a metal sleeve be it in a shock or a leaf spring etc doesn't matter it takes a even amount of pressure to press it into place. When replacing bushings generally shops will burn the rubber rather than try to press it out.
So for it to have come out says it was not the right size or it had worn off enough for it slide out.
One should be able to get a replacement bushing (don't search for Vespa shock absorber bushing, find the dimensions of the bushing (outer and inner diameters and width) I am sure there are plenty of PU bushings of that size out there.
Pressing it in is as one of the earlier posts suggesting pressed in using a socket of the size and a vise and some lube on the inside of the shock sleeve where the bushing will go in.
Why it is in the state it is can be due to one of the many theories espoused. Time shall be spent figuring that out for sure, but I think less time will be needed to put in a new bushing or a replacement shock.
If you need a replacement shock, I believe I have a pair of rear shocks for the GTS 300, they are from 2010, I had replaced mine with Malossi shocks, and they can be yours, send me a message with your address and I'll mail them out to you. You could pay the mailing costs.

If you replace the nut, use a Nyloc one.
They are far less likely to come loose.

The shock nut is a nyloc type of nut. It uses metal tags to prevent undoing. It cannot come off unless it is not done up or torqued correctly (much too loose). The design of the shock, washer and nut is such on later models that if the rubber bushing breaks free from the shock the shock cannot come free from it's mounting as in the picture. The washer and nut prevent that from happening. It has a fail safe design. My shock will not go over the washer, I've had a longer look at it. If you think about it, no designer will allow safety to be compromised by relying on a rubber bush alone to hold the shock in place. I wouldn't. There is considerable stress on that mounting particularly with two folks onboard.

I think earlier models could come off, which might be why later models have a bigger washer fitted? I still highly suspect the bush is held in place securely and it's the shock that's moved off it.

There should be minimal side load on that bush in normal operation.

Where is the OP when you need then, a picture is worth a thousand words.

That is the right answer.

When Rocket was having handling issues last year I found the ridht shock connection looking exactly like this.

The bushing slipped. Mine was a Malossi shock.

I slid it back on and used a washer large enough to go past the bushing.

That wasn’t the problem but glad I caught it.

Bill

It might well be! Just would like to know for sure. OP where are you?

The rubber bushing must be changed every time it is removed from its seat because it deforms and putting it back no longer performs its function well (also because once it is out it expands ..).

As per my previous posts above...if the bushing fails the shock cannot come off the suspension shaft if the nut and washer are in place. I've double checked my bike, a 2016 GTS300 and a 2012 GTS300. Both had very large washers preventing the shock from breaking free of it's mount should the bushing fail. This is how designers make things completely safe. They don't rely on just a press fit or "glued in" bushing. Nut and washer are both missing on the OP's bike for sure.

Wheres the OP?

By the time that Piaggio built your 2012 and 2016 models, they had changed to the large washer.

My 2006 had a small washer.

I fixed it by replacing that with a large one like yours.

Bill

It would be nice if the OP had taken a picture from a different direction so it would be clear if the nut was there or not! That might take "blame" off the guy who last installed the shock and maybe put it on some pencil pusher at Vespa who decided a smaller washer was cheaper.

As someone who pulled wrenches for a living for 45 years I can in someway sympathize with a mechanic who gets interrupted in the middle of a job. More times than I would like to remember it happened to me.

Just imagine being halfway through torqueing the heads on a 16 cylinder diesel engine and have a boss come in and demand that you go check out a problem on some other machine!

My way of dealing with it was to if at all possible to leave the torque wrench and socket on the last bolt I had tightened. If that was not possible use a paint marker to mark the bolt and stick a note saying where I was when I left. I was lucky in that most of the time I worked alone on most projects so did not have to worry about someone else coming along to finish the job.

I agree with this in principal, but I’m not 100% positive they’ve always been built with that principal in mind. I checked my relatively unmolested 2010 Super, and it has the large washer holding the bottom of the shock in place. My 2008 GTS 250 does not, though it has had the engine out a number of times and that could very well be my own neglect.

I think best practice is clearly to use a large (and sturdy) washer that spans a diameter larger than the OD of the bushing.

Hi jess, yes it's possible someone has put the wrong washer on your bike, and indeed the OP's bike.

However, I've checked the Piaggio online parts list for all GT/GTS bikes, and one old paper copy from 2009 and they all use the same large washer. It's a large heavy duty washer part number: 013962. It's the same for all GT200/GTS250/300 bikes. It's not been a backward upgrade applied to all models either according to my Vespa/Piaggio dealer. It has always been. If someone has a smaller washer it's either come from the factory with the wrong washer on it (pretty unlikely) or someone has made a mistake while servicing the bike and put a smaller washer on it. It's dangerous to have anything smaller than the standard size washer that completely covers the bushing area. The OP's bike is a 2013 so it will have had the the standard washer all GTS bike have (unless the wrong one was fitted by the OP or a tech) and it's impossible for the shock to come off if the bushing fails. So this all points to the nut not being torqued correctly or even not been put on in my book.

I think too, some folks are looking at the washer on their bike from above at an angle and this can give the impression the washer is actually slightly smaller than it is. If you get down and take a look from the side on as in my photo, it makes it clearer to see that the washer is larger than the hole the bushing goes through. In any event the OP's bike I'm sure cannot have it's nut and washer still in place even if it did have the wrong smaller washer holding the bushing. It would take up too much space in the shock to sit like it is. And tbh a bushing will not normally fail like that if it's torqued up correctly, even with very high mileage on it. But it will tear free of the shock if it's not held in place properly by the nut and washer.

Last edited by Stromrider on Sat Jul 24, 2021 6:23 am; edited 1 time in total

Well, that someone would undoubtedly be me, since I’m the only one who has ever serviced that bike Fair enough. It would make sense for there to be a large washer there. I was leaving open the possibility that it had changed somewhere during the years, but if you’re confident it was present on the GT200, then that seems a pretty good indication that it has always been there.

Could someone post a picture of what this is supposed to look like? Thanks.