General Motors 4L60-E Transmission • Problems & Solutions

Introduction to the 4L60-E Transmission:

     Known as one of the most mass-produced transmissions in automotive history, there are no shortage of 4L60-E transmissions on the road. As with most mass-produced transmissions, their cheap factory design is fertile for reliability and drivability concerns in almost any application. 

     Additionally, it can be difficult to find credible information on this unit. At Next Gen Drivetrain, our years of engineering and manufacturing expertise allow us to offer the highest quality 4L60-E transmissions and torque converters in existence.

      In this installment of our popular Drivetrain 101 series, we will be publicizing much of our internal information as product of years and years of research and development. Our goal is to empower consumers and transmission experts alike as to the 4L60-E transmission, how it fails, and how it can be made superior for any application.

In this Drivetrain 101, we will be addressing:

- The most popular failures we witness on the 4L60-E transmission

- Ways to get the most out of your transmission

- The strengths (believe it or not, there are a few!) of this transmission

- Resources for relevant updates and upgrades

And much, much more!

>>> View our 4L60-E Transmissions & Parts Catalog Here!

General Motors 4L60-E Product Resources:

- 4L60-E Transmissions
- 4L60-E Torque Converters
- 4L60-E Rebuild Kits
- 4L60-E Valve Bodies
- 4L60-E Parts

Popular Transmission Information Resources:

- Top 5 Benefits of an Upgraded or Built Transmission
- Calculating Torque Multiplication Factor, Why is it So Important?
- Top 5 Ways to Extend the Life of a Factory Transmission

A Brief History of the 4L60-E Transmission:

     The 4L60-E transmission is an electronic evolution of the historical 700R4/4L60 transmission of years passed. This means that instead of using a mechanical governor device to manage line pressure, it uses electronics inside the transmission to do so.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     As the popularity of electronically managed transmissions grew, the 4L60-E transmission was implemented in model year 1993 in large trucks and SUV’s, later making its way to passenger vehicles in 1994. This served as a permanent shift from purely mechanical to electronic transmissions for General Motors vehicles.

     Come 2013, the demand for 5 and 6 speed transmissions had forced an end to the 4L60-E transmission. It’s successor, the 6L80-E transmission then became commonplace in General Motors vehicles for years to come, signaling a retirement of the 4L60-E transmission indefinitely. Without further ado, let us analyze the prolific problems of this transmission and how we resolve them.

Problem #1 - The Valve Body

     As with most units, the 4L60-E transmission’s valve body is designed to be cheap for mass manufacturing, and not superior for longevity, performance and drivability. They are known for driving fine off the lot, and developing poor shift quality and unpredictable behavior as the miles tack on, especially in demanding applications.

     One major problem is the separator plate. It’s quite thin and offers little protection against crossleakage. The 4L60-E transmission case featured many oil circuits and acts as the upper part of the valve body, similar to transmissions like the Ford E40D. This means the separator plate has a highly demanding job to which it often begins to fail.

     In resolution, a thicker separator plate with thicker paper bonding materials is standard in all Next Gen 4L60-E transmissions. This, coupled with our precision flatted valve body mating surfaces insulates the valve body of the transmission from these concerns as the mileage tacks on, ensuring consistent shift quality at any stage of life.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     Further, the valves in this transmission are mostly made of aluminum like many General Motors products. Although this is not directly an issue, the aluminum valves are connected to bore wear in the valve body as well as sticking valves. As the valves begin to pierce the bore, they no longer stay straight. This further exacerbated the issue and results in oil draining out of certain circuits under pressure causing clutches to burnt or shifts to flare.

     As is commonplace in many Next Gen products, we utilize CNC ground steel valves that prevent these problems from developing in the first place. These valves, coupled with modified springs designed to optimize for reliability and shift quality, result in the best shifting valve bodies available with near infinite personalizability.

Problem #2 - The OEM Servos

     The 4L60-E transmission utilized a servo to activate 2nd gear and 4th gear. As is consistent with General Motors orthodoxy, they are almost all made of plastic. As one could imagine, the intense heat and large amounts of pressure contribute to physical failure of these servos in even OEM applications.

     Even worse, these systems are “oil dams.” Oil dams are surfaces that when broken, oil will billow out under pressure, causing catastrophic failure to the transmission. Fortunately, there are multiple resolutions to these problems that can be implemented during a remanufacturing process.

     General Motors recognized this flaw and used a congruent servo, but simply made of cast aluminum, in the Corvette of the time. These servos can be directly interchanged in other units as a massive longevity upgrade, allowing this failure to be not of concern.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     For applications where there are large power demands and likely abuse, a physically oversized CNC machined billet aluminum alternative exists for both the 2nd gear and 4th gear servo to ensure not only unmatched reliability, but added holding force to support heavy vehicles or vehicles with large power potential.

     Regardless of execution, upgrading the OEM servos is absolutely necessary to ensure a reliable 4L60-E transmission. This is a frequently overlooked modification that is standard in all levels of Next Gen Drivetrain product. 

Problem #3 - The Torque Converter

     Historically, the Achilles’ Heel of most General Motors transmissions is the torque converter assembly. The 4L60-E transmission is in keeping with its heritage as having a wildly unreliable torque converter assembly from the factory. Furthermore, it robs the vehicle of power and contributes to excess heat in operation.

     The most common problem encountered in day to day use is flexion of the cover of the torque converter, causing a vibration during lockup as well as inadequate holding force when the converter clutches are applied. It is because of this that a billet CNC machined cover is standard on all Next Gen Drivetrain 4L60-E torque converters. 

     Stall speed is another point of concern. The factory stall speed is fine for the most basic applications but certainly doesn’t support modified vehicles. It can be very complicated to modify stall speed to support the individual needs of the application.

     We specialize strongly in modifying stall speed to enable the most out of any vehicle. From billet stator assemblies to fin modifications, we can adjust stall speed to virtually any reasonable number. This is a critical aspect of any proper 4L60-E transmission build.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     As a standard across all Next Gen 4L60-E transmissions, the torque converter is upgraded to support a reliable and comfortable driving experience. This is a large reason for our coveted Next Gen smoothness and low operating temperatures.

Problem #4 - The High Pressure Oil Pump

     Following the pattern of race and vane style pumps of General Motors transmissions from years passed, the 4L60-E transmission is known for a variety of pump problems. These will often result in poor line pressure, high temperatures, flared shifts and other generic drivability concerns.

     Additionally, the oil pump of the 4L60-E transmission features multiple sets of valves, similar to the valve body, that are prone to bore wear. This results in a loss of line pressure that becomes progressively worse as more line pressure is commanded.

     Bore wear is prevented with the use of our sleeved boost valve assembly, and CNC machined steel pressure regulator valve that is physically oversized to permanently insulate the oil pump from the problems associated with valve bore wear.

     Further, the use of coated steel pump vanes prevents the oil pump from losing efficiency as miles tack on. The result is a 4L60-E transmission that maintains its oil pump efficiency indefinitely and with no regard to mileage or application; another large contributor to our coveted shift quality.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

Problem #5 - The Input Shaft Assembly

     The input shaft is the mechanical component in the transmission that splines into the torque converter and allows power flow to continue to the inner gearsets of the 4L60-E transmission. Although for modest applications it can be generally reliable, those applying added power or weight to their vehicles can find this to be a liability.

     When the input shaft fails, this can cause catastrophic collateral damage to nearby components such as the oil pump assembly and the input drum. This is an excellent “peace of mind” upgrade recommended for almost any extracurricular application.

     As one could imagine, Next Gen Drivetrain offers multiple solutions to this problem. We manufacture two different billet input shafts for the 4L60-E transmission. One, is a 300M billet steel material for general use and is intermediate level builds. The other is an AERMET billet steel material, designed to support the most ridiculous applications imaginable.

Problem #6 - The Intermediate Shaft Assembly

     The intermediate shaft, you guessed it, is the next shaft behind the input shaft of the 4L60-E transmission. This is sometimes referred to as the main shaft or output shaft in some publications. When it fails, it can be exceptionally destructive failure, often wiping out much of the core.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     Much like the input shaft, it can be upgraded with higher quality materials that negate these concerns. Also akin to the input shaft, we offer both a 300M and AERMET billet steel alternative, standard in all relevant builds.

Problem #7 - The Input Drum Assembly

     Consisting of the overrun and 3-4 clutch assemblies, the input drum is notorious for failure in applications with added power or weight. This further contributes to poor shift quality into 4th gear, compromising highway performance for a variety of vehicles.

     Plus, when these clutches fail, the 4L60-E transmission requires a complete rebuild, an expensive proposition. Physically adding clutches to the assembly is critical for demanding applications, but can even be justified for lower level builds simply looking for the most reliable product.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     At Next Gen, even our most entry level builds will contain higher quality frictions in this critical area. But, as the demands of the build increase, we offer a billet drum assembly with bolt together anchor system that enables us to add multiple additional friction plates over stock, compounding the load capacity of the 4L60-E transmission.

Problem #8 - The Reaction Shell Assembly

     The reaction shell found in the 4L60-E transmission is stamped steel, and very weak. A common negligent practice when driving a vehicle is shifting into drive while backing up before completed stopping the vehicle. On many transmissions, the torque converter absorbs the load and this is of minimal concern. On the 4L60-E transmission, this shreds the factory reaction shell at the splines.

     This problem is easily resolved with the use of a hardened steel reinforced reaction shell, ensuring that aggressive use at low speeds does not plague the 4L60-E transmission. This is especially important on heavier vehicles but applies to everybody.

Problem #9 - The Intermediate Band Assembly

     An easy area for improvement is the factory intermediate band. The OEM band assembly is very thin, not adequately utilizing the entire outer drum as friction surface. Analogically speaking, this would be like having brake pads that are half the width of the rotor itself. You could make the brakes double the size and still use the factory rotors, equating to better braking force.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

     This is the complication with the factory band, it can be made nearly twice as thick and still function perfectly, equating to a roughly proportionate load capacity increase. An oversized kevlar material band is standard on all Next Gen Drivetrain 4L60-E transmissions.

Problem #10 - The Oil Pan

    The factory transmission oil pan was designed to accomplish one thing and one thing only, save money. This pan is stamped from a heated up sheet of steel that isn’t strong enough to withstand any level of shock or maltreatment. The pans are also incredibly shallow, barely even allowing the factory filters to function properly.

     This is an objectively horrible decision and does not contribute to the longevity, health or operation of the transmission. Something to take into consideration when considering a deep transmission pan is the added time between transmission service intervals. Adding 20-30% more oil extends the amount of time between transmission services by a roughly similar figure. The same logic also applies to heat.

     Added benefits of an aftermarket pan include the implementation of a drain plug. This makes the act of servicing your transmission extremely fast, easy and clean. The factory pan does not come with any of these benefits, leaving it the least qualified option of any. A deep pan be among your first considerations when upgrading the problematic 4L60-E transmission.

>>> View our 4L60-E Transmissions & Parts Catalog Here!

Conclusion to the 4L60-E Transmission:

     Few transmissions have been produced in greater numbers than the prolific 4L60-E transmission. Fortunately, this massive volume has paid for explosive amounts of research and development across the transmission industry.

     At Next Gen Drivetrain, we pride ourselves in being at the front line of these efforts, designing and manufacturing 4L60-E transmissions to only the highest standards. Still have questions about your 4L60-E transmission? Call in and speak to one of our knowledgeable experts today!