Primary Shaft is also known as output shafts. It revolves at a distinct pace in addition to offers obligatory torque on the cars. In this particular transmission, when overdrive is engaged, a shaft that's attached into the housing in the torque converter (that's bolted into the flywheel of the engine) https://gearbox-auto30741.snack-blog.com/33753149/gearbox-auto-no-further-a-mystery