Sierra Saph with a 2.9 24V Granda Scorpio engine and a type 9 G/Box.

It keeps cutting out, someone has told me that a mt75 is needed and that the problem is there is no speed sensor on the type9.

I can;t remember where but i read something about a cable speed sensor.

Can anyone suggest whats needed to alleviate the problem whilst sticking with the type9 box?

Cheers

Avi