The 6T40 is a General Motors Hydra-Matic six-speed automatic transmission. It is designed for front-wheel-drive cars with the increasingly common transverse crankshaft orientation. The GM 6T40 and its sibling Hydra-Matic six-speed transmissions are designed for greater simplicity, and streamlined to reduce their dimensions and weight. The GM Hydra-Matic 6T40 six-speed automatic transmission also features clutch-to-clutch functionality that allows it to fit into about the same amount of space as an automatic four-speed transmission. The compact design means fuel savings for car owners.

The 6T40 has an expanded drive ratio, with first gear at a very high ratio for quick acceleration from a stopped position. But, the sixth gear ratio is for overdrive to minimize engine friction and maximize fuel economy during highway driving. 

The 6T40 transmission features the on-axis design for which the GM transaxles are known. The 6T40 has all gearing aligned with the crankshaft centerline of the engine. That arrangement affords vehicle owners the benefit of a shorter-length car and a vertically shorter powertrain, for the overall result of more room in the car cabin interior.

Its three planetary gear sets, two rotating clutches, and electronic clutch controls enable the realization of the 6T40’s particular clutch-to-clutch design concept for optimized shift timing.

The special MHH version of the 6T40 transmission is designed to employ its eAssist system, which administers mild electrification to boost fuel economy. Internal modifications to the hardware and clutch controls are substantial in the 6T40 MHH featuring the eAssist. This advancement improves shifting responsiveness and efficiency while maintaining optimum driving and acceleration performance and eliminating superfluous automatic shifting.

When your 6T40 transmission eventually exhibits symptoms of wear and tear, of course, it must be replaced as quickly as possible to restore your vehicle to reliable condition. Instead of buying a new 6T40 transmission or having your existing 6T40 rebuilt, installing a remanufactured transmission typically offers the best overall value.

Installing a used transmission naturally means you can expect a shorter life expectancy from this major component than from a new or remanufactured one. A rebuilt transmission contains only enough replacement parts to update just the defective or worn-out components. Logically, this is a less than entirely practical long-term alternative to a remanufactured transmission. Merely rebuilding sets up a situation in which old and new internal parts are becoming unequally worn. That operating condition lends to additional potential problems before the end of the lifespan you should expect from a replacement transmission.

A remanufactured transmission is not the same as a rebuilt one. Remanufacturing means that every internal working part is replaced with a new or re-machined component. That process produces a 6T40 transmission replacement unit that can deliver the greater strength, long-term durability, and reliable functioning you need for your vehicle. 

We also correct all known defects in the original manufacturing of the transmission parts. So, our remanufactured 6T40 transmission may last longer than the original new factory-built transmission.

Buying and installing a remanufactured 6T40 transmission typically costs significantly less than a new unit. Quality remanufacturing provides the dependability you need in a transmission to ensure your safety and convenience and peace of mind when driving your vehicle. 

Reman-Transmissions offers up to a 36-month / unlimited mileage warranty for the 6T40 transmission. We do not charge a core charge for the first 30 days. The warranty on a used 6T40 transmission from Reman-Transmissions is 6 months or 6,000 miles. We charge only $270 for shipping. We also provide the industry’s best customer support for the 6T40.