How a ZF5 Transmission Works | Full ZF S5-42 Teardown & Gear Explanation

In this video, we tear down a used ZF S5-42 diesel transmission from roughly 1995 and show exactly how it comes apart, how the gear train is laid out, and how power flows through the transmission. Once the case is apart, we lay out the main shaft and countershaft assemblies on the table and walk through how engine power is transferred through the different gears. From there, we break down the shift tower assembly and demonstrate how the synchro rings engage using the input shaft. This is a standalone ZF5 teardown video, separate from our current rebuild series. The rebuild episodes are still coming, this transmission was torn down mainly to help us better explain the internals and to gather spare parts for the build. If you enjoy transmission teardowns, manual gearbox internals, and seeing how things actually work inside the case, this one’s for you.