Thanks guys, I found that site earlier but it shows up 3 different sizes of shafts, 63,75 and 78mm.
I ruled out the 63 but it still could have been the other 2.
Found this site after a bit of searching which helped http://www.bensrc.com/10341_exploded.htm
I only used the car for 10 minutes after breaking the engine in and kerbed it, broke 5 pieces in total.
They have cost me more than half of what the GF paid for the whole car in the first place. I guess this is going to be a expensive hobby