Today I went back to Turbo Hydromatic again, the third time attachment We are looking at us at an important point in the timeline of automatic transmissions. Fuel economy pressure and consumer performance demands from the government have increased significantly in the meantime since the debut of THM in 1964. In other words, THM400, the main shifter. GM has branched into THM350, THM250, and the very problematic THM200 and so on.
In 1987, GM moved away from the traditional THM naming scheme and switched to a new combination of letters and numbers. The number, layout, and strength of gears combined to turn the THM400 into a 3L80. By then, however, large gearboxes were limited to larger truck applications.The passenger car has moved to four Forward gear after the dawn of the 80’s.
General Motors followed a costly class action proceeding in 1979 regarding the fragile THM200. With two goals in mind, General has set the transmission engineer to make some changes to the THM200. And we will be able to meet the needs of passenger cars in the future.
To that end, all problematic components of the THM200 have been replaced with improved and redesigned components. While they were tinkering with the 200, engineers added a handy additional 4th gear in a 0.67: 1 ratio. The improved box was called the THM200-4R when it debuted in 1981.
The 200-4R uses a multi-case bell housing and is compatible with various rear-wheel drive vehicles included in the GM lineup. The multi-case featured a dual-bolt pattern as opposed to the standard-case single-bolt pattern, which only fits the specific vehicle designed. The mounting position of 200-4R matches the mounting position of THM400. The new 4-speed is about the same size as the old THM350, and the 200-4R is an easy upgrade to the old model so equipped.
GM was convinced that the 200-4R was a better transmission and that the mainline car needed 4th gear. In this way, the new transmission was rolled out in 1981 with a full lineup of full-size B-body. Pontiac Bonneville, Oldsmobile Delta 88, Buick LeSabre and others benefited from the 200-4R. It has also been used in large C-body cars such as the Buick Electra and Cadillac Deville since 1981.
The additional use of the 200-4R occurred in 1983 when it was used in medium-sized G-body cars such as the Buick Regal and Oldsmobile Cutlass Supreme. When GM introduced a miniaturized front-wheel drive vehicle in 1985, the C-body was renamed to D. So the 200-4R continued with a special luxury usage: Cadillac Fleetwood Broam.
4th gear found a high performance niche in the 80’s when it was chosen as the gearbox for the Buick Grand National. In 1989, it was used in the Indy 500 pace car version of the Pontiac Firebird Trans Am. The 200-4R performed well, but was phased out in 1990 after the last outing with B-body and D-body cars.
A year after the 200-4R, another 4-speed appeared: THM700R4. From the 1982 model, the 700R4 was mainly used on Chevrolet and GMC cars. The application was more limited due to the single case bell housing, but it was widespread in many models given its development. The transmission adopted GM’s new naming scheme when it became 4L60 in 1990. 4-speed, vertical layout, 60 strength rating. From now on, we will use modern naming.
Additional improvements between 1984 and 1987 included updated internal components such as oil pump housings and ring gears. In late 1986, the 4L60 was also equipped with a new auxiliary valve body. The next major change occurred in the 1993 model, with the introduction of the 4L60-E version.
The -E suffix means that electronic controls have been added. In short, the transmission relied on the powertrain control module (PCM) to indicate when to shift. Newly modernized-E was implemented in GM’s trucks, vans and SUVs in 1993. In 1994, it was widely used in GM’s rear-wheel drive passenger cars.
From there, the box has been updated with a bolt-on bell housing, which makes it much easier to fit in other vehicles. By 1998, all cars equipped with the 4L60-E were equipped with bolt-on bell housings, and the box became popular on more models. That year, a new torque converter with a more rugged design was introduced. It was also revised in the 90’s to comply with the new OBD-II regulations.
4L60-E has been available since 1993 2013.. GM actually kept 4th gear as much as possible, but other manufacturers upgraded to 5-speed, 6-speed, and even 8-speed automatic. Longtime enthusiasts of the 60-E included the Chevrolet Suburban 1500, which used it from 1993 to 2009. The Camaro had four speeds in the F-body guise from 1994 to 2002 when it was canceled.
Elsewhere, Chevrolet Colorado used it from 2004 to 2012, and Australians found it in Holden Caprice from 1994 to 2008. It was also used on the GMT360 SUV, including the exclusive and very different Saab 9-7X. Its last use was the 2013 Chevrolet Express Van (a van that is still in production).
In the heyday of 4L60-E, a more robust version, 4L65-E, was introduced. Introduced in 2001, it was only used in passenger cars with a larger V8 engine (usually 6.0 liters of Vortec). The main uses were GMC Sierra and Yukon Denali, Cadillac Escalade, and the dreaded Hummer H2.
It was also shipped to Australia for use with the 6.0 liter Holden Commodore and sent to Kentucky for the 2005 Corvette. A quick cry to the 4L70-E, which was a 4L65-E with an internal speed sensor. Since 2013, the 4L60 and 65 have been replaced by the 6-speed 6L80 and 6L90. Return to THM400 / 3L80.
As mentioned last time, the 3L80 was last used in 1990 in GM’s large vans like the G20 and Bandura. It’s rugged and popular, but it’s time for the 3-speed to give way to the 4-speed version. Production of the 4L80-E began in 1991. The 4-speed with electronic control was the first major change to the old THM400 since its debut in 1964.
Unlike its predecessor, which had to play the role of many passenger cars, the widespread use of GM’s 4L60 meant that the 4L80 was limited to pickups, vans, and commercial vehicles. All 4L80s were manufactured on the Willow Run transmission (1953-2010) in Ypsilanti, Michigan. The 80-E has a rated torque of up to 440lb-ft and a maximum GVWR of 18,000 pounds.
GM used the 4L80 throughout the pickup line on the 1500, 2500, and 3500 versions of the Chevrolet Silverado, GMC Sierra, Chevrolet Express and GMC Sabana. It was also used in the often forgotten 2500 version of Chevy Avalanche. It continued until 2013 with the use of vans until 2009, and with the use of trucks and SUVs in GM.
However, like its 3-speed four-bearer, the 4L80 was used by non-GM companies that needed a transmission that could motivate great power and weight. Most THM400 users only migrated to 4L80 when it became available. One of the first manufacturers to buy a 4-speed was Bentley and Rolls-Royce (at the time together as one company).
Bentley used it for all versions of the Eight, Turbo R, and the very expensive Continental Coupe. After that, under the guidance of BMW, it continued to be used in all versions of Arnage from 1999 to 2006. Rolls-Royce continued to use THM400 as part of its lineup, so it was used in Silver Spirit and Silver Spur (1992-1998).
The 4L80 was added to the Hummer H1 in 1992 when the military truck was edited for the use of wealthy individual consumers by the Hollywood people. A year later, Jaguar added it to the dilapidated XJS and remained until the end of the 1996 coupe run. It was also the motivation for the Haipo XJR from 1994 to 1997. It was also paired with the company’s V12 sedan. (XJ12 and Daimler Double Six) Between 1993 and 1997.
The British also used another 4L80. Probably the most amazing. In 1996 Aston Martin (Ford’s property) called GM for some 4 speeds for the new DB7. To be fair, the 4L80 was limited to the in-line 6-cylinder version of the DB7. This is because other flavors of V12 used ZF or Tremec boxes.
The low usage was the rugged take of 4L80, 4L95-E. It was designed for use on vehicles with a torque of up to 690 lb-ft and a GVWR of 18,000 lbs. The 85 was used exclusively on older 8.1-liter V8 GM cars. Used when Express and Savana are equipped with a Duramax diesel engine.
It was also used in the Local Motors (2007-2022) Rally Fighter, an off-road dune buggy built between 2010 and 2016. The rally fighter was a combination of a small 6.2-liter V8 and a 4L95, and was used in all 30 units. Examples created in those 7 years.
And with the completion of the 4L60 and 4L80 in 2013, the history of Turbo-Hydramatic has come to an end. GM has moved to a 6-speed transmission, a product that was not designed on its own. The lateral application saw a 6L80 based on the 6T70 and ZF 6-speed co-developed by Ford-GM. Are there any suggestions that need to be covered next with abandoned history submissions?
Become a TTAC insider.Get the latest news, features, TTAC takes and all the truth about all the cars first Our subscription Newsletter..
General Motors Turbo Hydromatic Transmission (Part III)
Source link General Motors Turbo Hydromatic Transmission (Part III)