Controlling the GM 4L60E with the COMPUSHIFT Transmission Control System

Introduction

The GM 4L60E introduced in 1993 is the successor to the Turbo-Hydromatic 350 (TH350). It is General Motors first automatic transmission with overdrive and electronic controls, which brought about a new era of sophistication and more precise control of automatic transmissions.

History of the 4L60E

The 4L60 transmission was in production for over 25 years and it has gone through a number of different iterations and name changes in that time. In 1982, GM came out with the 700R4 transmission. A longitudinal 4-speed automatic overdrive transmission which later got renamed to be the 4L60 in 1990.

In 1993, the 4L60 had the E added to it to become 4L60E, which indicated the use of electronic shift controls in the transmission. Then in 1995 GM added a Pulse-Width-Modulation (PWM) torque converter clutch solenoid for smoother engagement.

There are an early and late model 4L60E transmissions. The later models introduced from 1996 have a removable bell housing which isn’t interchangeable with the early models. From 1998 onwards, all models of the 4L60E produced were late models. The advantage of the removable bell housing is that multiple engine bell housing patterns can be adapted to the same transmission case.

In 2001 the 4L65E was released as an upgrade. It looked just like the 4L60E on the outside but had stronger internal parts including a five-pinion planetary carrier, along with a better torque converter and input shaft. GM later introduced the stronger 4L70E in 2006 which was just like the 4L65, but had an input shaft speed sensor located in the pump and eventually they added a more reliable internal mode switch (IMS). The 4L60E and 4L65E were both very successful transmissions and were featured in GM vehicles until 2013, before getting phased out to make way for newer 6-speed automatic transmissions.

Specifications of the 4L60E

Manufacturer General Motors
Type 4 Speed Longitudinal Automatic
Predecessor TH350
Length 21.9"
Input Shaft 298 mm
Overdrive Yes
Case Material Die Cast Aluminum
Weight 146 pounds dry
Fluid Capacity 8.8 to 11.4 quarts
Max Input Torque 4L60E: 350 lb-ft
4L65E: 380 lb-ft
4L70E: 400 lb-ft
Max GVWR 8,600 lbs
Max GCWR 15,500 lbs
RPO Code 4L60E: M30
4L65E: M32
4L70E: M70

Gear Ratios

1st 2nd 3rd 4th R
3.06:1 1.62:1 1.00:1 0.70:1 2.29:1

The 4L60E provides a wide range of gear ratios. The high 1st gear ratio is ideal for pulling off quickly under acceleration and is especially good off-road or when carrying/pulling a heavy load. The 4th gear, also known as the overdrive gear, allows lower RPMs to be achieved at cruising speeds as well as a potentially higher overall top speed.

Strengths

The 4L60E is very capable of transmitting a lot of power and torque. It can be used in vehicles up to 8600 lbs. gross vehicle weight and can handle up to 360 ft·lbf or 480 Nm of torque. This makes it very fit for use in trucks, SUVs, jeeps, and even muscle cars.

The transmission is known for its good fuel economy. Overall it has lower gear ratios as well as an overdrive gear leading to better fuel economy and less wear on the engine over time. The torque converter can also lock up, which makes the input speed of the transmission the same as the engine output speed. Any extra slippage in the torque converter at highway or cruising speeds is energy wasted, and the Torque Converter Clutch (TCC) lockup allows for a direct drive from the engine to the transmission. Earlier GM transmissions used a fixed displacement gerotor pump that regulated pressure by bleeding off excess fluid. The pump introduced in the 4L60E is a variable displacement vane pump. This type of pump only moves the fluid necessary to achieve the pressure and flow needed in the transmission. The variable displacement style is much more efficient, especially at lower pressures associated with cruising. This improves the overall fuel economy of the vehicle.

The Pulse Width Modulation (PWM) torque converter clutch solenoid, which comes on all late models of the 4L60E, allows a smooth application and release of the torque converter clutch, and the adapted valve body which is controlled by electronic actuators and solenoid, makes the 4L60E easily controllable with a modern electronic transmission controller such as the COMPUSHIFT.

Interchangeability is a strong attribute of the 4L60E. The transmission is compatible with Chevrolet small block or big block V6 or V8 engines, as well as Inline 6 engines. A well built and maintained 4L60E is capable of potentially handling up to 700 horsepower.

Common problems

While the 4L60E is known to be quite a reliable transmission. There are a few problems that often show up over time. They are:

Failure of the 3-4 clutch pack. This specific clutch pack is known to have problems where the clutches burn due to slippage from oil leaking into the clutch pack. This clutch pack failure leads to slippage in 3rd gear.

Broken drive shell / sunshell. The sunshell is susceptible to break on the 4L60E. It is a common weak point that results in no 2nd, 4th and reverse gear. This sunshell in the 4L60E is often swapped out for a stronger aftermarket one if problems arise.

A worn Torque Converter Clutch (TCC) regulator valve. A worn TCC regulator valve causes an oil leak and this prevents the TCC from engaging, leading to slippage. When this happens, the engine RPM will rise much faster than the increase in the vehicle’s speed.

On the customer end, using the wrong TCC in the transmission or badly programming the COMPUSHIFT can lead to burning up the torque converter or erratic shifting.

Popular Vehicles that use the 4L60E

The 4L60E transmission was a very popular transmission during its production and had been featured in many different types of vehicles, as well as in various automakers overseas.

Being designed by General Motors, it was heavily used in the Detroit automaker’s own vehicles, as well as by other brands owned by GM, such as Chevrolet, Cadillac and Buick.

You can find a 4L60E in SUVs like the Chevrolet Suburban, muscle cars like the Corvette and even in sedans like the Holden Commodore made all the way down in Australia.


A 2007 Chevrolet Suburban


A 2001 Chevrolet Corvette Z06


A Holden VR Commodore from Australia

The 4L60E can also work well in Jeeps too and is good for 4x4 applications due to its ability to handle high input torque. However, it might not be very suitable for vehicles with a short wheelbase as the 4L60E is a bit long lengthwise.

When using the transmission in a 4x4 vehicle, the transfer case has to have a speed sensor to work with the COMPUSHIFT. If the transfer case doesn’t have a speed sensor, there are aftermarket kits to add an output speed sensor.

Controlling the 4L60E using the COMPUSHIFT

The 4L60E can come with either the 13-pin or 15-pin case plug. At the moment, not many transmissions are still currently using the 13-pin case plug, and it’s recommended that you upgrade to the 4L60 with the 15-pin case plug. There’s a 17-pin case plug as well but it’s only used with the 4L70E which has the internal mode switch.

Depending on the case plug you have, you will need to get the appropriate wiring harness for your transmission. In case you’re wondering, the COMPUSHIFT 4L80’s harness and 4L60’s harness are interchangeable.

Once you’ve got the right wiring harness, the COMPUSHIFT transmission controller can be programmed via Bluetooth using a smartphone to control shift speeds, shift quality and the torque converter clutch.

The controller needs to be connected to the TOSS, otherwise it won’t shift due to safety concerns.

Note that the Torque Converter Clutch engagement strategy is different on a diesel and petrol engine. There are presets already included for gasoline and diesel engines, and within the diesel category, you have two broad categories: low-speed diesels and high-speed diesels.

On a diesel engine, the TCC engagement strategy is different as it is tuned to get the engagement done sooner. Diesels have a peakier torque curve and you want to be able to increase throttle without the torque converter unlocking immediately.

On a gasoline engine which has a relatively flatter torque band, you can unlock the TCC to multiply torque.

To learn more about controlling your 4L60/65/70 transmission and to get the right kit for your build. Head on over to our dedicated page for more information on our 4L60E transmission controller.