Faulty Speedo

[sportique]

I just can not get my speedo to work I have replaced the plastic 'worm' inside the hub (plenty of grease) replaced both inner and outer speedo cables and still no joy . The speedo itself has been lubricated and works fine when you stick a drill on the end (nice and free) . The 'worm' part of the hub is clean and does not look damaged in any way .
However when everything is put back together the speedo works for a couple of minutes then

When the wheel is stripped down again the plastic 'worm' drive is chewed up

Anybody got any ideas ?

[Smallframe]

if you take your hub apart you will have an angled drive spline ring attached to the inner centre of ther hub. This is either damaged or infected with some foreign matter and thus demolishing the turnworm when you place it into the hub

[sportique]

I've checked that and it seems okay . It was a bit dirty but I scrapped the groves out with a srewdriver and greased it up a little . I may buy a new one anyway as I'm running out of ideas .

Cheers Smally .