Mercedes Benz 300SL (1990s) M104 3.0 Petrol Engine and 5spd Manual DOG LEG Gearbox

Price on request


Mercedes Benz 300SL Engine and Manual Gearbox

M104 3.0 inline 6 cylinder petrol engine 24-valve DOHC with Rare 717 5 speed manual dog-leg gearbox.

The engine is a 3.0 inline 6 cylinder M104 (981) built for a 300SL-24. It’s a 24valve DOHC. Mercedes used the M104 engines in the W124 300E, C124 300CE, S124 300TE and 300SL R129s.  The gearbox is a 717 (.451) 5 speed manual dog leg first gearbox. These were not fitted to many vehicles and are becoming increasingly hard to find in any condition. We’ve had more interest in the gearbox than the engine and we are open to splitting the gearbox and engine up, given the right offer.

We bought two of these Mercedes Benz engines and matching gearboxes from a very well known oil producer in the 90s. The two engines were originally purchased directly from Mercedes as crate engines. They were to be used as a test bench for proof testing oil. We sold the first engine soon after acquiring. That engine had been used for testing for a short while but was in fully running condition.

This engine for sale here was a surplus engine designated for oil proof testing that was prepared, but we were told, was never used for it’s intended purpose.

The engine for sale has testing related fittings and pipes installed but we believe this engine and gearbox to have never been run in anger and it has certainly never been in a vehicle. We were told it was their reserve unit in case the original suffered a malfunction but was never required. You will definitely need to perform a major service and lots of remedial work to replace the pipework, belts, electrics, and more. We have not seen inside this engine so can’t verify any of these claims. Viewing absolutely essential.

The engine also includes a stand-alone independent ECU that was to be used for the testing process while on a bench. See photos.

This engine is NOT ULEZ compliant.

Due to the nature of this unique listing we insist on a viewing in person before considering any sale.