Hermys has the exploded views on their website now too. There is a gear on the back of the speedo that is easy to check. If he had the front end apart maybe he didn't get the drive at the wheel engaged properly. If that is the case and everything was tightened back up it is probably damaged now.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!