Hey Reggio, welcome to SlotForum
First thing to say is that the Mega-G is designed
not to be taken apart. As it is a toy, it complies with strict US and European regulations that ensure even the most inquisitive child cannot ingest or inhale any small part.
So, the wheels stay on and the motor and traction magnets don't come out. The pick-up shoes, springs and the rear axle are designed come out to be replaced by spares. So too the pinion gear and guide pin. All these parts are available in the Mega-G Tune-Up Kit. This is from the back of the pack:
It's also possible to change the armature, brushes and brush springs. Scale Auto sell the armatures (Wizzard armatures fit too). The brushes and springs can be replaced with standard Wizzard components. Scale Engineering produce plastic motor bushings for the Mega-G.
The main thing for maintenance is to keep the chassis and components clean - I do this with cotton swabs to remove dirt and tweezers to remove any hair or fibres. Oil very sparingly on the front motor bushing and the gears. Change the pick-up shoes when they wear through.
The pick ups come off rather like the T-jet. They hook over the brush tubes in a way that does always ensure good connection. If you close that hook very slightly, you'll get a better connection.
There are some hop-ups you can do. One is to increase magnetic downforce by 'flipping' the traction mags:
Let us know if you want to know more