Craig,

Both cars are the rally version of Cen's..

Had some progress last night.. after putting the back end spur gears etc back onto my original Cen car we noticed the spring drop out.. So took the clutch apart like you said and put it back together.

I now have 1 working car. I will try and get onto cen for a new spring and ball bearing for car 2..

Thanks for all your help

Andy