- #History of the 700r4 transmission update
- #History of the 700r4 transmission manual
- #History of the 700r4 transmission tv
The transmission was further updated later in the '90s, garnering a removable bell housing, a 13 vane oil pump, and a 300 mm torque converter. The entire system was controlled by a computer (with processing duties shared between an on-board controller and the vehicle's ECU), which decided when it was time to shift the transmission.
#History of the 700r4 transmission tv
How did this work? Mechanically, the two transmissions were nearly identical, save for the lack of a valve body, TV cable, and governor, which were replaced by a vehicle speed sensor and a set of solenoids and actuators that shifted the gearbox from one ratio to the next.
Rather than continue to use a mechanical, hydraulic-based throttle valve shifting system, the 4L60 gained an 'E' in its title to reflect the fact that shifts were now controlled electronically.
#History of the 700r4 transmission update
The '4' referred to the number of forward gears, the 'L' indicated that it was intended for longitudinal drivetrains, and the '60' denoted it was appropriate to use with a gross vehicle weight rating of 6,000 lbs.ĭespite the new name the transmission soldiered forward status quo until 1993 when a major update was made. In 1990 the 700R4 lost its 'Turbo' tag permanently and was renamed the 4L60. These can be identified by looking for the auxiliary valve body, which is located underneath the pan. By 1987 the gearbox had reached its most reliable form, and the run of automatics produced between '87 and '93 are regarded as the most desirable of the lot. Much of this development came about after weak spots in the design were identified through its use in the third-generation F-Body Chevrolet Camaros and Pontiac Firebirds, as well as heavy-duty trucks. These included a revised oil pumps (moving to a 10 vane design), improved internal sealing, and stronger pump rings and pump seals. The transmission was largely a work in progress for GM, which continued to make changes and upgrades to the 700R4 throughout its lifespan. Highway rpm in some vehicles dropped by as much as 30 percent thanks to the 700R4. This spread helped give the transmission respectable off-the-line performance without drinking down too much gas at speeds above 55 mph, making it a major improvement in terms of drivability over the TH350 and the TH400 that had preceded it. All 700R4 transmissions offered a lock-up torque converter and a 0.69:1 overdrive gear, with a 3.06:1 first, a 1.625:1 second, and a direct-drive third gear ratio. Originally featuring a 27-spline output shaft, by 1985 the gearbox came to include a 30-spline output. Although the 'TH' stood for 'Turbo Hydra-Matic, the gearbox quickly became known simply as the 700R4, thanks in large part to being included across a surprisingly wide spectrum of rear-wheel drive and 4x4 vehicles. One of the easiest ways to do this was invest in a new generation of overdrive-equipped automatic transmissions that could keep the revs down at highway speeds. Deep Rootsīy the end of the 1970s General Motors was looking for ways to reduce fuel consumption across its entire range of vehicles. Together, the 700R4 and its 4L60E update have shifted generations of modern Chevrolet, Pontiac, Oldsmobile, Buick, and GMC eight-cylinder engines, and their history ties back to the very first Turbo-Hydramatic transmissions built by General Motors. If you're upgrading, modifying, or swapping in a GM-sourced V8 engine, there's an even stronger possibility that you've looked at either the 700R4 or the 4L60E, two of the most common, and popular, automatic transmissions of the past 40 years. Whether you're building a comfortable restomod cruiser or a lightning-fast drag car, chances are you've at least considered an automatic gearbox.
#History of the 700r4 transmission manual
Although manual gearboxes get all the glory on the high performance scene, the reality is that automatic transmissions are far more common-and in some applications, much quicker in a straight line than a clutch-equipped vehicle.
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