The Model 3's drive unit and battery pack are both manufactured at the Gigafactory and sent to Fremont for final assembly.
Tesla Motors has reportedly confirmed that the Gigafactory will play a significant role in Model 3 production beyond simply supplying battery cells.
The company apparently plans to build the mass-market sedan's drive units and complete battery packs in Nevada. The components will then be shipped to Fremont for final assembly into the vehicle.
"Tonight, I'm pleased to announce that Tesla will expand its investment in Nevada by producing the electric motors and gear boxes for the Model 3 at the Gigafactory," Nevada Governor Brian Sandoval said in his recent State of the State Address, as quoted by Electrek.
Tesla recently received approval to expand its California factory, but Sandoval suggests the plant is currently 'filled' and required some processes to be shifted to the larger Nevada site.
The company is said to be launching a hiring spree for the Gigafactory, adding 550 new jobs. The plant is still far below its eventual target of at least 6,500 workers when production volume ramps up.