Speedo cable or clocks?

[Mitching]

Replaced the bulbs in the clocks the other day, put it all back together and everything worked fine.
Then a couple of days ago when driving I noticed the speedo needle started shaking.

Then it started shaking up until about 65mph, then after a while I was going along the motorway in the fast lane, was revving at about 4k in 5th gear but the speedo said I was doing 60mph which wasn't right.

Then when driving in residential areas I noticed that in 1st and 2nd gear the speedo needle refuses to move at all, and once I get to about 30 or 40 mph it aggressively shakes from 3rd gear upwards, out of synch by about 20mph.
I thought the speedo cable was loose so took the dash apart again, disconnected then reconnected the cable and put it all back together, with no change to the needle.

The speedo cable is sturdily attached to the gearbox.

Could this mean new speedo cable? Or could I have damaged the clocks when changing the bulbs in them?

[Jimmyrallye]

Had the same sort of problem with mine with needle shakeing.... Then eventualy it stopped all together a new speedo cable sorted this .. Whilst i took dash of it had snapped just behind the clock!! Just be care full takeing the cog out the box as i dropped mine in gearbox and it kept jamming up in my gearbox

[stainesy]

I have the same problem now. After inspecting mine I have figures out its the worm drive cog on rge end inside the gearbox is warn. Keep trying to change now but I can't get the metal casing out of my gearbox to do it.

[Mitching]

Not had a go at taking the speedo cable out of the gear box yet, is it a particularly fiddly job?
I imagined it would be fairly straight forward like it is in the back of the clocks.

Although with a mk2 things are never as straight forward as they seem 

[stainesy]

its as simple as undoing one bolt holding the cover on the bit in the gearbox then just pulling it out and changing the plastic cog on the end. such a simple job. but mine is propper stuck and can not get the bloody thing out.

[Jimmyrallye]

It is a simple job i got mine of easy and old one came out nicely .. It wos when i fitted it to new cable lineing the cog back up in the gearbox got it in there just needed to go down that extra 3mm but wouldnt went to pull it out (gently) and it fell off doh!!! Im not worried any way as ive done a 20vt conversion now .... Just be carefull you can buy the red cogs of ebay any way for a few quid worst case scenerio

[Mitching]

Ah thought so, I knew it involved a bolt on the box, but wasn't sure how secure the cog would be!
Should be interesting getting it through the bulkhead, will probably have to tape the new cable to the old cable and pull it through.

Just need to find a cable locally for cheap now!

[stainesy]

You may not need to change the cable mate. Just change the plastic cog (worm drive) on the end.
That's allium trying to do. I will probably have to change my cable as I recon I'm gona have to butcher mine to get it out. 

[Mitching]

You may not need to change the cable mate. Just change the plastic cog (worm drive) on the end.
That's allium trying to do. I will probably have to change my cable as I recon I'm gona have to butcher mine to get it out. 

That could be the case, but with it being 20 odd years old I may as well do the whole thing, just for piece of mind really.

[stainesy]

yeah spose your right