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Discussion Starter #1
I remember reading somewhere on this board that Alfa’s always have three things wrong with them and you should careful fixing one thing you know is not that much of an issue as the one that replaces it might be!
Anyway, one of my three is my Speedo, I recently replaced the cable and since then it has not worked. It’s screwed in at both ends ok and I’m sure it’s the right way round. If I take the bottom end of the cable out and attach to a drill it will move the Speedo gauge, if I disconnect the top end with the bottom end still attached to the engine and drive along, the cable doesn’t spin. Any ideas? (I don’t have the old cable as it had broken)
 

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presuming it is for the gtv (so simple cable, no speed gen. or the likes)

1st question I suppose is did the speedo ever work? (;))

my bets are, when you tightened the knurled knob at the tranny end, you might not have located the square cable drive correctly into the tranny drive and if so you can still pull the cable in/out somewhat...is that the case?
like shown here (also a GTV and his cable didn't turn)
https://www.alfabb.com/bb/forums/486671-post3.html

If so, try to relocate it again.

Could also be the little spacer has gone awol (if it had one)...w/o that (if fitted) it can flop about too.
https://www.alfabb.com/bb/forums/ge...ft/171945-speedo-cable-spacer-tranny-end.html

Failing that, (hopefully not) a problem with the drive itself in that the square female end has rounded off so the cable does not get turned.
 

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Discussion Starter #4
Thanks Dom, yes the Speedo worked before. I had actually found the post about the slipping cable but everything is tight and looks like you would expect it to. I’ve disconnected and reconnected a few times without success and was wondering if it was the piece it connects to ‘tranny end’. Will take it apart again and check everything over, but do you know what the part is called that turns the Speedo cable? I’ll take some pictures tomorrow, hopefully they will show Something.
 

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the mechanism is usually called the "speedo drive gear" and that is run off the "output yoke"
both seen here
https://www.alfabb.com/bb/forums/5872121-post3.html

the drive gear cog needs to match up with the helical gear on the output yoke, dependant on your rear axle ratio, so for instance a 4:1 axle ratio might have 13 teeth on the cog and 6 on the yoke (usually stamped on the cog of the drive gear such: 6/13)
 

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Discussion Starter #6
the mechanism is usually called the "speedo drive gear" and that is run off the "output yoke"
both seen here
https://www.alfabb.com/bb/forums/5872121-post3.html

the drive gear cog needs to match up with the helical gear on the output yoke, dependant on your rear axle ratio, so for instance a 4:1 axle ratio might have 13 teeth on the cog and 6 on the yoke (usually stamped on the cog of the drive gear such: 6/13)
I’ve just had a chance to remove the cable and replace. Everything seems tight and fitting as it should, but still no luck. Have attached a cou0le if photos, not sure how much use they are. How do I know if the Speedo gear needs replacing?
 

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there is some kind of mix up here, methinks;)
I was talking speedo (as your title says)

but those photos are of the rev counter drive on the water pump, not the speedometer drive which is on the gearbox....
:)
 

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Discussion Starter #8
Well that explains a lot, not sure at what point I got confused, but my rev meter works brilliantly! Right, now need to order a new cable and start again. I’ve found the Speedo cable has some damage mid cable, which would explain the issue, just got to replace the right one. Thanks for your help Dom, saved me more hours of frustration,
 
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