Before you say "This doesn't work" check which colour are the borders of the thumbnail.
Yellow=algodoo, orange=algodoo demo, grey=phun.
then check if you don't know what version is your algodoo/phun.
Propably the chain. This is what I did to it: chain density=100, chain hinges = autobrake and +inf torque, gear density = 100, made invisible circles to the wheels so it doesn't bounce, added damping to the spring.