As several production 'bottlenecks' still constrain output, Tesla now expects to reach its 5,000/week milestone by late Q1 2018.

Tesla has shed more light on Model 3 production problems, finally admitting that the ramp up schedule has been pushed back by a few months.Confirming recent unofficial reports, the automaker says its primary production constraint involves the battery module assembly line at its Nevada Gigafactory.

"The biggest challenge is that the first two zones of a four zone process, key elements of which were done by manufacturing systems suppliers, had to be taken over and significantly redesigned by Tesla," the company wrote in its Q3 investor letter. "We have redirected our best engineering talent to fine-tune the automated processes and related robotic programming, and we are confident that throughput will increase substantially in upcoming weeks and ultimately be capable of production rates significantly greater than the original specification."

Due to the battery module issue and other unspecified bottlenecks, the automaker does not expect to hit its 5,000/week milestone until late in the first quarter of next year.

Other manufacturing lines, including the drive unit, seat assembly, paint shop and stamping, are already capable of running at over 1,000 units per week. Welding and final vehicle assembly, meanwhile, are around 500 units per week.