speedo not working

[Gavinsmithartist]

K series 1.6 roadsport, 2000.

Speedo has jumped about a bit between 40 and 60. Had been told the speedo probably wants reconditioning, although it has only done 10k.

Now its stopped all together. So I took out the speedo to check connections etc.

With the speedo out, I have held the cable and it turns when I'm reversing, but doesn't turn in forward gears!?

 

Any advise, knowledge appreciated.

 

Gav

[Stationary M25 Traveller]

Look at the gearbox end of the cable ..... on the drivers side of the gearbox underneath. Look at the right angle drive output. Removable after getting at the circlip. See what you find.

[John Vine]

If the cable turns in reverse but not in forward gears, it could be there's a fault with the drive gear in the gearbox tail-housing. Maybe the retaining caps are loose or worn and are allowing too much lateral movement in the gear spindle?

 

Or it could be a problem with the worm gear, or (as SM25T suggests) the quill (this connects the speedo drive gear to the cable via this fella).

 

JV

[Gavinsmithartist]

Thanks for the above.

Stripped out the buts that i can, and all seem to be turning.

The quill turns OK and I can see that the transition gear thing is turning, but when all connected the speedo cable doesn't. But the speedo cable attached to the gear thingy all turns OK when attached to drill.

Could something be worn not to work under load?

How difficult to change the quill or worm on g'box?

Any advise or help appreciated.

[John Vine]

Is the gearbox end of the cable inner damaged at all? Rounded off perhaps (that is, no longer square section), so that it doesn't engage properly in the angle drive? Are you sure the squared end of the cable is fully home in the angle drive? The other possibility from your description could be the angle drive itself. Does the quill turn OK in both directions? Is the cable inner actually continuous (that is, in one piece, with no fraying)?

 

Changing the quill is a doddle, although removing the angle drive can be fiddly. But if you've already removed the angle drive, you can simply pull out the quill with pliers as it's a loose fit. Getting at the worm gear is a gearbox-out job, although there are reports of in-situ repairs here.

 

JV