Gearbox failure!

Gearbox questions & answers etc..

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alexanderfoti
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Gearbox failure!

Post by alexanderfoti » Sat Jul 21, 2012 11:11 pm

Hi all

After a lovely weather ride back today I had a jumping/chunching sound from my gearbox, to only then loose 3rd and 4th (the gear lever just went stiff).

I am going to pull the side off the box tomorrow, fingers crossed I don't find too much damage in there!

Rhynri
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Re: Gearbox failure!

Post by Rhynri » Sun Jul 22, 2012 4:31 pm

All fingers in my household crossed for you, although the dog is not too happy about it. :P

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Sun Jul 22, 2012 4:35 pm

After pulling it of I find what appears to be a tooth missing from my pinion high gear:

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Now, I have been told its from a 35H assembly/engine.

Can anybody confirm if this is the case, and if I have identified the right part? This is my first time dismantling any gearbox so im a bit worried it wont go back together :P

Also, any idea how this happend? I have no idea :(

sorry the dog comment went straight over my head :p explain ? :)

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Sun Jul 22, 2012 6:01 pm

Also, does this kit, replace the ball bearings you can see in the picture?

(hitccocks sealed bearing kit)

Image

nvm, obviously wont, completely different gearbox :p

Image

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Sun Jul 22, 2012 9:37 pm

Also, can anybody point me to any good instructions for rebuilding these, all the links I have are for Enfield gearboxes, which are similar, but have some notable differences!

gilburton
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Re: Gearbox failure!

Post by gilburton » Mon Jul 23, 2012 10:46 am

Sorry to hear about the failure. You have to remember these gearboxes were designed for a relatively low powered 2 stroke.
I can't find a rebuild link but there are plenty of books/gearboxes available on ebay. If you do a general web search for villiers there are still plenty of people doing spares for them.
They are a bit difficult to identify but use a lot of common parts so a specialist should be able to help if you send pics/numbers.
Now as for lubrication you should not be using grease or a grease mixture in a villiers box. It's a straight sae 30 oil. You could increase this a bit but no grease.
You mentioned in another post to me about the gearbox leaking oil so I should imagine the combination of wrong lubricant/leaks may be the answer??
try www.villiersservices.co.uk for gaskets etc. and the gears you require. Apart from ebay try the classic bike mags as there are often ads in there.Personally I'd just get another box from ebay or an autojumble.
One question what have you done about the open joint where the gearbox bolts to the original engine?? I presume you have fitted a leakproof steel blanking plate?? or combined plate/mounting?
Hope that helps :D

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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 11:08 am

Many thanks!

Aha, I was under the impression initially that it was an Enfield gearbox, hence the grease filling.

Now that I know its a Villiers unit, it would also explain why I sheared a shaft it if was only designed for 2t power rather than the heavy surges from the diesel!

The issue I had with normal oil in the box is that it leaked out, mainly through the output shaft! :( I did constantly top it up but it was still a pain.

I will have to phone Villiers services as they don't have the gasket on their website.

The open joint is the side on the right hand side of the picture, there is thick paper gasket between this and the plate that is the bolted to the bottom of the engine, no leaks from here luckily :)

The big question is, do I rebuild this box, or put an Enfield box in it, if it cant take the power then there is no real point in rebuilding it :(

gilburton
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Re: Gearbox failure!

Post by gilburton » Mon Jul 23, 2012 11:27 am

The complete gasket set is £10 so you'll have some surplus engine gaskets. You'll still need the replacement gears and oil seals £50+if you want to stop the leaks. As I said there are a few gearboxes on ebay at the moment and probably cheaper than replacement parts. If you do buy one make sure all the gears work and before you fit it tip it up and fill it with diesel or similar and give it a good soak then turn the shafts etc. to give it a good clean out and check for leaks from the shafts.
You probably won't get the clutch etc but it's a fair bet yours will fit.
If you can get another box enfield,bsa etc then measure it first as they are much bigger than the Villiers and the primary case will be longer.
Enfield spares will be cheaper and easier to get but unless you want to rebuild your bike I would stick with the villiers.
They did fit these engines to 3 wheelers etc. so they are not bad but they are old so will need a bit of maintenance to keep them in good shape so cure the leaks first.
Contact villiers services with your numbers/pics and with a bit of luck they will tell you the actual box then you can decide and it will give you an idea of which box to buy or repair. :D
ps are the other gears ok??
Last edited by gilburton on Mon Jul 23, 2012 11:37 am, edited 1 time in total.

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 11:36 am

Many thanks.

I just gave them a call, and mentioned the oil leaks specifically. The chap on the end of the phone said that if you replace the high gear pinion, you will also replace the bush which is where the oil is probably leaking out from (it leaks onto the clutch and then into the primary).

The issue with getting another box is that mine has a 27t trials gear fitted, so the whole gearing is around that, so if I get another one that is mayb 25t, I will have to change gearbox sprocket, rear sprocket size and chain lenghth :(

I think/hope the reason the gear failed is because of the wrong lubucration I had in the box (And not enough of it!)

You don't know which seals I should change per chance do you :)

gilburton
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Re: Gearbox failure!

Post by gilburton » Mon Jul 23, 2012 11:53 am

go to http://www.villiers.info and there are exploded diagrams. I think you said yours was an H model?? click on 1H etc.
I imagine if it's the output shaft you need to replace the seal behind the drive sprocket but check the bearing for wear (items 4 & 6) If this is worn your seal won't last long. The good news is the seal is probably standard so take it out and the bearings etc and take it to your local bearings factor or get the number off it and order it. I don't think it will be anything special so should be readily available for a couple of pounds.
That just leaves sourcing the gears??

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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 12:06 pm

I Have since found it its a 32a 9e 4 speed :)

I have spoken to villers services who can supply the gear for 35 pounds :p

I will pull the gears off and have a look at the bearing and the seals :)

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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 1:03 pm

I have pulled the gears, the beraing looks to be in good condition and is nice and smooth, but seing as its out I will replace it anyway.

Another issue is that the seal is a bit torn, and the seal surface is a bit scarred, see the picture below:

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Do you think I can fix the bent bit with a hammer and chisel or a socket and hammer to try and straighten it out.

gilburton
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Re: Gearbox failure!

Post by gilburton » Mon Jul 23, 2012 1:29 pm

No wonder it was leaking :D Knock it out inside to out ,get the number off it or take it to a local bearing supplier or just order the bits when you order the gear.. When you refit it remember the open/spring side goes to the inside. You have to tap it in squarely and gently. The favourite tool is a large socket just smaller than the diameter of the seal. Work your way gently round when tapping it in. If you bend it at all throw it away and get another. When you replace the cover a dab of oil round the shaft helps slide it over without damage. You could practice by putting the old seal back but it will go in easier than a new seal so take it easy. There are some general "how to" videos on youtube
When you say the bearing is smooth have you tried lifting the shaft up and down when it is in place?? Too much movement will cause the seal to fail.
I thought you meant straightening the seal but I think you mean the thin metal bit at the bottom of the pic?? If so this might be just a thrust washer does it come out? If so straighten it then if not something with a flat surface like a drift or possibly a long bolt but nothing sharp.
Was this damage caused by the previous owner?? or did something else cause it ? Whatever the reason if you think you have cured it it should be ok for many miles :D

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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 1:56 pm

Yeah there was a little bit of play up and down but very small, it did look like it was offset slightly so that plus the whole clutch mechanism could have caused it to fail.

Not sure how the damage was caused, it will remain a mystery :(

Yes i mean the piece of metal in the bottom pic, it appears to be one piece and the diagrams dont show an additional piece of metal . I will have a go at straightening it. Now just to hear back in pricing for all the extra parts i need :(

Thanks for all your help and I will keep you updated

Rhynri
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Re: Gearbox failure!

Post by Rhynri » Mon Jul 23, 2012 3:23 pm

alexanderfoti wrote:sorry the dog comment went straight over my head :p explain ? :)
Just try to force a dog's toes to cross and you'll see what I mean! :P

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 3:23 pm

Rhynri wrote:
alexanderfoti wrote:sorry the dog comment went straight over my head :p explain ? :)
Just try to force a dog's toes to cross and you'll see what I mean! :P
Ahhhh heh, I see what you mean :p

Rhynri
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Re: Gearbox failure!

Post by Rhynri » Mon Jul 23, 2012 4:06 pm

Good good. And about that gearbox, make sure you get all those metal shavings out of there! Any guess on how much its going to set you back to fix? Sorry that it broke on you!

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 4:12 pm

Many thanks.

Yeah I will give it a good clean! Im guessing around 50-100 pounds :( I havent even broken into 1000 miles yet, annoyingly my rewound stator failed on the same day, now barely charges the battery again, so the flywheel must come off.

Eventually I will have all the problem sorted.

Rhynri
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Re: Gearbox failure!

Post by Rhynri » Mon Jul 23, 2012 4:14 pm

Ouch, well, I guess that is just the cost of being on the bleeding (read: 1930's) edge of motorcycle science. Just to think if they had kept the good old diesel in motorcycles. :cry:

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 5:19 pm

Rhynri wrote:Ouch, well, I guess that is just the cost of being on the bleeding (read: 1930's) edge of motorcycle science. Just to think if they had kept the good old diesel in motorcycles. :cry:
Heh I know, I wish there was a better way than using a 50 year old gearbox design, Surely you would think there is something out there in the same price range that can handle 10 bhp, with a built in clutch, but apart from CVT or expensive Ultima boxes, there appears to be nothing!, Maybe using the bottom end/gearbox from another engine would work, but it would make the whole arrangement very long.

Rhynri
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Re: Gearbox failure!

Post by Rhynri » Mon Jul 23, 2012 6:58 pm

When I get rich, I'll just have to design an engine/gearbox based on the opinions of people on this forum. It seems to be the only option. :twisted:

alexanderfoti
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Re: Gearbox failure!

Post by alexanderfoti » Mon Jul 23, 2012 7:03 pm

Rhynri wrote:When I get rich, I'll just have to design an engine/gearbox based on the opinions of people on this forum. It seems to be the only option. :twisted:
My thoughts exactly!

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