The auto system on this caliber is very simple. The reverser is really just a pinion on the rotor which is held in one direction by a click spring. The pinion needs to turn freely (minus the spring) on the rotor, and be lubricated. When hand winding the pinion spins past the click; if the lubrication has become sticky the rotor will spin. Use a plastic pointed stick (or two) to remove the clip holding the rotor on, it's very easy to scratch the rotor with metal tools.
If you do a full service on it, beware of using alcohol on the date support (it's a full plate made of acrylic that covers the dial side)- alcohol will damage it. It's possible that the latest executions changed the plastic but I don't think so. I wouldn't recommend it as a first chronograph, it's a robust movement but has some tricky parts to deal with.
Here's a manual