ZF5 Transmission

Specifications

The ZF5 transmission is a heavy-duty, fully synchronized 5-speed manual gearbox developed by ZF Friedrichshafen and widely used in Ford, Chevrolet, and Dodge diesel and gas trucks from the late 1980s through the late 1990s. It is known for its exceptional strength and durability, making it ideal for towing and commercial use. The ZF5 features five forward gears with overdrive and a granny-low first gear for improved launch under heavy loads. It was commonly paired with engines such as the Ford 7.3L IDI and Power Stroke diesel, 6.9L diesel, and big-block gasoline engines.

Depending on the variant, the ZF5 handles torque ratings of around 420–470 lb-ft, uses synthetic manual transmission fluid (ATF or Mercon, model-dependent), and employs an internal hydraulic clutch system. Its cast-iron case, top-mounted shifter, and smooth gear engagement make the ZF5 a legendary manual transmission valued for longevity, reliability, and strong performance in demanding truck applications.

Transmission Variants

S5-42 (1987–1994)

The ZF S5-42 is the original ZF5 manual transmission used primarily in Ford F-250 and F-350 trucks. Rated for approximately 420 lb-ft of torque, it was commonly paired with gasoline engines and early diesel platforms such as the 6.9L and 7.3L IDI. It featured a cast-iron case, fully synchronized five-speed design, a granny-low first gear, and overdrive, making it well suited for towing and general heavy-duty use.

S5-47 (1995–1997)

The ZF S5-47 was an upgraded version of the ZF5, incorporating stronger internal components, improved metallurgy, and enhanced bearings to increase torque capacity to about 470 lb-ft. While retaining the same gear ratios as the S5-42, it was designed to handle higher-output engines, most notably the 7.3L Power Stroke diesel and big-block gasoline engines, and was used in F-250, F-350, and F-450 trucks.

S5-47M

The ZF S5-47M is a medium-duty variant of the S5-47 developed for commercial and high-GVWR applications. Sharing the same basic design and torque rating, it was configured for compatibility with larger trucks such as the F-550, often featuring provisions for heavier clutch assemblies and PTO use. This version was optimized for sustained heavy loads and vocational service, emphasizing durability and long-term reliability.

Frequently Asked Questions