Front break conversion & speedo drive set up - Issues

Hi all.
I am looking for some guidance and hope someone can help, please.
I'm trying to help a friend who has an external hydraulic break conversion on his GP. The make is 'SPAQ'.
The problem is, is that we cannot get the steel worm (driven) gear to mesh with the steel (drive) gear fitted to the hub once the inner speedo cable to located into the drive bush (steel drive retaining housing) and tightened down . When the wheel is spun, the inner cable turns freely when it located into the end of the worm gear and whilst in the hub WITHOUT the drive bush! This seems to suggest the drive bush (drive retaining housing) is at issue?!
Have others had similar issues? Am I overlook something? Any suggestions? Can you recommend a particular supplier who supplies a speedo kit to overcome the problem?
Essentially, its 'doing my head-in' and any guidance would be very much welcome.
Many thanks. H.
I am looking for some guidance and hope someone can help, please.
I'm trying to help a friend who has an external hydraulic break conversion on his GP. The make is 'SPAQ'.
The problem is, is that we cannot get the steel worm (driven) gear to mesh with the steel (drive) gear fitted to the hub once the inner speedo cable to located into the drive bush (steel drive retaining housing) and tightened down . When the wheel is spun, the inner cable turns freely when it located into the end of the worm gear and whilst in the hub WITHOUT the drive bush! This seems to suggest the drive bush (drive retaining housing) is at issue?!
Have others had similar issues? Am I overlook something? Any suggestions? Can you recommend a particular supplier who supplies a speedo kit to overcome the problem?
Essentially, its 'doing my head-in' and any guidance would be very much welcome.
Many thanks. H.