Hi Roger,
Thanks for your reply.....I have built the car up as per instruction manual, and while I had the gearboxes apart yesterday doing the shimming I rechecked the slipper shaft etc and all seems to be in order.
I've done a lil vid showing the movement on the shaft
http://www.youtube.com/watch?v=AKer21eCF4w
I've got a feeling I may need to shim the shaft out??
Cheers
Lee