Speedo Drive

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MalcW
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Speedo Drive

Post by MalcW »

Back in July I bought a new speedo drive for the rear wheel from the club spares, reamed it out as required, and fitted it. Yesterday my speedo was erratic, reading slow and getting worse. The cable seemed fine so I took the drive box off the wheel to take a look. It doesn't turn more that half way before jamming, and it doesn't always jam in the same place. It's only done about 7 - 800 miles or so, so it certainly shouldn't be worn out. It took precautions at the time, but I can only guess that a small bit of swarf from reaming it has got into the mechanism? It was greased before use by the way.
Anyway, I've ordered another, but I wanted to see if anyone else has had problems, or has suggestions for working on the new one.

Malc
Mick D
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Re: Speedo Drive

Post by Mick D »

Hi

If I remember correctly the speedo gearbox relies on the wheel spindle assembly to keep the gears correctly meshed, don't suppose you tried spinning the rear wheel and observing the square drive before you removed the gearbox? If not I'd put it back on and have a look.

Are you sure your cable inner is intact and the correct length?

As a last resort why not take it apart? chances are you can rectify the fault and if you make a pigs ear of it you've got a replacement on the way.

Regards Mick
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clive
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Re: Speedo Drive

Post by clive »

If it is the torpedo type box you should be sble to get the end off. This would allow the worm to be removed and you could then flood the works and see if you can get any swarf out. Refitting the end piece may benefit from a bit of superglue to keep it in place.
clive
if it ain't broke don't fix
MalcW
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Re: Speedo Drive

Post by MalcW »

clive wrote:If it is the torpedo type box you should be sble to get the end off. This would allow the worm to be removed and you could then flood the works and see if you can get any swarf out. Refitting the end piece may benefit from a bit of superglue to keep it in place.
I'll give it a try. How does it come off? Just tap something into the joint and lever it off?

Cheers,

Malc
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clive
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Re: Speedo Drive

Post by clive »

If the torpedo type thats how i have got them off. The flat end ones unscrew. If there is significant wear on the worm it can cross thread with the drive.
clive
if it ain't broke don't fix
Mick D
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Location: Aberdeenshire

Re: Speedo Drive

Post by Mick D »

Hi

Here's a rather nice animation that demonstrates assembly:



Regards Mick
MalcW
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Re: Speedo Drive

Post by MalcW »

Thanks Mick, that's very useful.

Malc
56G80S
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Re: Speedo Drive

Post by 56G80S »

Great post Mick
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