It’s overwhelming to shop for a pickup, especially if you are looking for a diesel pickup with a manual transmission. In fact, there are few diesel pickups available today. Here are the three best manual transmissions for diesel trucks available today.
ZF6
Produced by ZF Friedrichshafen AG of Germany, the ZF6 six-speed transmission is practically legendary. Everything the ZF5 transmission was and more, the ZF6 stands as it was the most powerful manual diesel truck transmission ever manufactured.
The ZF6 featured a forward gear and an all-aluminum body. The transmission is unique because it features an internal oil pump. This design reduces friction between the main shaft gears and constant mesh by circulating oil to an exterior cooler at the front.
Virtually no light-duty manual transmissions had this feature before the ZF6’s introduction.
Chevrolet adopted the ZF6 later to power its Duramax Diesel engine. This transmission was an alternative to the Allison. The ZF6 received a new bell-housing design and an external oil pump. It also had a higher cut gear, quieter operation, and a lower operating noise. This transmission was the last one GM used for light-duty diesels, before discontinuing all manual transmissions. Read more about the rebuilt ZF6 transmissions here.
NV5600
The NV5600 manual transmission was designed to replace the 5-speed NV4500. It is a 6-speed manual transmission that was developed by the New Venture Gear transmission partnership between General Motors, Chrysler, and General Motors. The NV5600 was used in Dodge trucks from 1998 to 2005.
While the NV5600 had a better gear spread and greater torque capacity than its predecessor, design issues necessitated a redesign of the shaft, clutch, and synchronizer assemblies in 2001. Some NV5600 units manufactured between 1998 and 2000 also had problems with their synchronizers and a weak input shaft.
An upgrade improved the clutch, input shaft, and synchro design, which addressed many of the issues that owners were having, particularly when towing heavy loads. There’s access to an NV5600 transmission compatibility chart here, https://reman-transmission.com/transmission-codes/?code=NV5600.
Cummins Turbo Diesel
The 2018 Ram 2500 was one of the very last pickups you could purchase with both a diesel engine and manual transmission. If towing power is your chief concern, considered that equipped with a fifth wheel, the Ram 2500 can tow up to 31,210 pounds.
FAQs About Manual Transmissions for Diesel Engines
What are the advantages of a manual transmission?
Manual transmissions are more fun to drive because you have full control over which gears to use and when to shift. They are also less likely to be less expensive than vehicles with an automatic and cost less to repair.
What are the disadvantages of a manual transmission?
Learning to drive a manual transmission can prove difficult. They can also be difficult to use in heavy traffic.
Can you still get a new pickup with a manual transmission?
Pickups with manual transmissions are rare. The last pickups you can buy with a manual transmission include the Toyota Tacoma and the Jeep Gladiator. The Nissan Frontier used to have a manual transmission, but that option was removed by the automaker.
The Bottom Line
Both the Cummins Turbo Diesel engine and the New Venture Gear 5600 have many advantages. But history and experience have shown that the ZF6 transmission is the best manual transmission available for diesel trucks.
