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4L80E Transmission Spotlight

4L80E Transmission

The 4L80E was a series of automatic transmissions from General Motors designed for longitudinal engine configurations. It was a new model based on the design of the Turbo-Hydramatic 400, first produced in the year 1963. 4L80Es were initially only available in Chevrolet or GMC trucks, vans, and commercial vehicles, as well as the Hummer H1. It was also adopted by Rolls Royce in 1991 and modified initially for use in the Bentley Continental R, and later other Rolls Royce, Bentley, and Aston Martin luxury vehicles.

The 4L80 nomenclature denotes that the transmission is a 4-Speed, Longitudinally-mounted, and for 8000 lbs. vehicle weights. Maximum engine input torque for the 4L80 is 440 ft. lbs. and the maximum output torque is 885 ft. lbs. The case is die-cast aluminum and was designed for vehicles up to 16,500 lbs. It’s RPO code is “MT1″ and has been domestically manufactured in GM’s Ypsilanti and Willow Run plants.

The torque converter is a fluid turbine drive and like those on its predecessor transmissions; the TH350C, 700R4, and 4L60, the 4L80E features a lock-up pressure plate for direct mechanically coupled driving from the engine crank. The 4L80E also features a 310 mm torque converter. As to length, this transmission is 26-1/4” long. This transmission typically accepts a 6.3-quart fill and features a dry weight of 254 lbs. that can weight up to ~268 lbs. when full. Like some earlier automatic transmissions, the 4L80E features one line pressure tap available for testing and diagnostic purposes, and also feature transmission cooling ports for external transmission oil coolers.

The 4L80E is intended to operate between the duty range of the 4L60E and the Allison series transmissions, and prior to the current high-powered light-duty (2500-3500 series) truck diesel revolution, Allison transmissions were essentially only used in the medium-duty class (4000 series) trucks. This made the 4L80E the go-to transmission of the era, amongst the popular Big Block style gas and diesel engines of the 1990’s.

In 2006, with the introduction of the landmark and innovative upstart, the 4L80 began to be replaced in several applications, which was without a doubt GM engineers’ ultimate intention. Yet, the 4L80 continued to be used in the GM’s truck line-up such as in 2007 when it was introduced into the Suburban and Yukon XL vehicles with the 6.0L engine.

The 4L80’s staying power found it installed in several vehicles through 2009, such as the G-series vans, the AM General Hummvee, the W-Series, Isuzu and Workhorse chassis trucks. GM 4L80E transmissions are often overlooked, yet is a top-rated leading option. This four-speed overdrive trans works with just about any power level and engine combination. It is based largely on the TH400 in strength and parts. The difference is the added overdrive gear, advanced electronic controls, and a lock-up torque converter.