Reina92

Hi all, just finished building the Sian FKP37. Unfortunately I have noticed something isn't working correctly. When rolling the car, the rear tyres are moving different (e.g. forwards) than the front tyres (e.g. backwards) do. This makes it impossible to drive with the car. Probably I have constructed something wrong (differential perhaps), but I don't know how to easily solve this problem? Anybody any thoughts on this issue (what to do and how best to resolve)? Thanks in advance for your reply!!