4L60E Transmission Mods That You Can Count On

It is every car lover’s dream for their vehicle to be fast, optimally use fuel, and offer an acceptable level of performance. One way each of these can be made possible is through simple 4L60E performance transmission upgrades.

Now, the automatic transmission has come a long way because, for almost 40 years, car manufacturers have had their fair share of hassle while trying to design the best fuel economy engine. Their attempts are evident in the use of a computer-operated carburetors and even an electronic throttle body fuel injection in a bid to slow down fuel consumption.

These aside, there are 4L60E mods that can make your car the dream ride you’ve envisioned and that is why we’ve outlined some upgrades which you can definitely count on to build a performance car with the toughest transmission.

History of the 4L60E Transmission

Before the advent of the 4L60E transmission, car manufacturers had a bone of contention while striving to bring about a vehicle’s fuel economy.

General Motors, for instance, devised the Turbo-Hydramatic 700R4 overdrive automatic transmission in 1982 as an upgrade to the TH350 three-speed automatic.

The 700R4 was quite unique in comparison with previous models which were designed by the company. This is because its shift modulation was carried out with the use of a device known as the throttle valve (TV) cable.

While the TV cable was able to modulate shift programming using throttle position and vehicle speed, it was still unable to bring about a perfect balance between fuel economy, driveability, and longevity.

Another problem that was posed, is irregularities in the line pressure and timing when a car owner improperly adjusts the TV cable. The latter could potentially lead to the 700R4 transmission being burnt.

Years later, the 700R4 was appended to 4L60 where the “4” denotes “four-speed”, “L” for “longitudinal installation,” and “6” for “light-to-medium-duty use and 6,000-pounds gross vehicle weight.” Despite this, the problem of shift programming which was evident in the 700R4 also reared its ugly head in the 4L60.

This led to the development of 4L60E, a computer-controlled transmission that is still based on the 700R4. The new 4L60E featured a powertrain control module (PCM) which is able to control shifts using the feedback provided by the throttle position sensor (TPS), vehicle speed sensor (VSS), and other sensors.

Today, you can find the 4L60E transmissions in GM vehicles such as:

• Chevy Camaro
• Chevy Silverado
• Cadillac Escalade
• Pontiac Trans Am

Now that’s out of the way, let’s show you a step by step 4L60E transmission rebuild.

4L60E Mods for Performance Enthusiasts

There are several 4L60E mods you can count on as a performance enthusiast, but no matter how tempting it may be to do it yourself, you need to ensure that you are a transmission builder who has garnered a lot of experience.

If that isn’t feasible, then you’re better off letting a mechanic do the work for you. Accordingly, highlighted below are some of performance upgrades for greater torque capacity which you can try out.

Keep in mind that the goal is to increase the torque capacity to handle 400-500 horsepower. Now, let’s dive in:

1. Lay out the important parts on an assembly bench.
   As a rule, always lay out the high-performance parts on an assembly bench in order to ensure that you do not miss out on the parts that are in dire need of enhancement. You can then proceed to thoroughly clean, inspect, and paint the transmission core.
2. Rebuild with an improved, thicker sun shell.
   4L60E has a weakness and that is the factory sun reaction shell where it breaks around the hub and will, therefore, not stand the test of time. On the other hand, 4L60E builds carried out with a thicker sun shell that is stronger can prevent failure.
3. Use five-pinion front/rear planetary.
   An OEM five-pinion front/rear planet will help to increase the torque capacity and distribute the torque across a larger mechanical surface area. It will also enable your 4L60E transmission to handle 400-500 horsepower which is equivalent to a 20 percent increase in torque capacity. There’s also the order of 6,500-7,000-pound gross weight it can help your machine achieve. To that effect, use the five-pinion front planet as well as a ring gear instead of the original four-pinion front/rear planetary.
4. Use a larger clutch with an input drum reinforcement sleeve.
   In this case, you can try out a larger 3-4 clutch overrun clutch apply piston while also using a reinforcement sleeve. The result is increased stability and hydraulic holding power. Keep in mind that stability and smoothness are also determined by having less friction and as such, consideration has to be given to the Teflon-impregnated stator support bushing.
5. Stamped Steel forward clutch apply pistons.
   You have the option of settling for a forward clutch apply pistons that are made of steel or cast piece. When either is compared, one with a stamped steel is the better option because it is less prone to failure while in use. Thus, it should be what you’re out to get while building your 4L60E transmission.
6. Use more clutches and larger gear band servo pistons.
   For a greater band-apply capacity of around 18 percent, use larger gear band servo pistons. There’s also the need to use seven clutches (3-4 clutches/drum) including the Raybestos forward, reverse input clutches, and overrun. A Raybestos ZPak 3-4 clutch pack, for instance, features materials that reduce friction and as such, help to dissipate heat.
7. 4L60E Trio series input shafts.
   Another easy 4L60E mod is the use of a trio 4L60E series input shaft in order to improve the transmission’s toughness. These input shafts include the stock 4L60E input shaft, a  heavy-duty 4L60E input shaft (4L75E), and a hardened 4L60E input shaft.
8. Use a high-volume 13-element pump.
   You can also upgrade your 4L60E to a high-volume 13-element (vane) pump which will handle pressure and volume.
9. Inspect Transmission soft and hard parts.
   There’s also a need to inspect and upgrade the transmission’s soft and hard parts as the case may be. For the soft parts, this will include clutches, seals, bushings, among others.
10. Use an Anti-chatter spring.
    You may have gotten a five-pinion rear planet and Raybestos high-performance clutches installed on the 4L60E build, but you can take it one step further. But this time around, it’s with the use of an anti-chatter spring.
11. Resurface clutch drums.
    Another needful step in your need for more power is to resurface clutch drums in order to provide better band engagement.
12. Load reverse input clutch drum with Raybestos high-performance clutch frictions.
    In a bid to eliminate clutch slippage and excessive heat that could kill the automatic transmission, you can load the reverse input clutch drum with Raybestos high-performance clutch frictions. Raybestos high-performance frictions are known to provide a firmer grip and without slippage. Nonetheless, it is still normal to have some amount of clutch slippage but when excessive, it calls for it to be checked in order not to shorten transmission life. This is because clutch slippage in itself is the greatest generator of heat.
13. Use Teflon sealing rings.
    Instead of relying on the usual iron sealing rings that do not last, you can take advantage of Teflon sealing rings. However, Teflon sealing rings are harder to install even though they are tougher and do not break like iron.
14. Load the reverse input drum onto the input drum.
    Proceed to load the reverse input drum onto the input drum which has already been fitted with a hardened input shaft.
15. Install the Raybestos Pro Series band.
    As one of the final approaches to the 4L60E modification, install the Raybestos Pro Series band and tie it to the servo. You also need to ensure that it has been properly adjusted.
16. Install the 13-element high-capacity front pump.
    Right before you install the torque converter, install the 13-element high-capacity front pump. For the torque converter’s installment, you will need to ascertain the stall speed and where the engine’s curve begins in order to get the best performance.

The Reward That Keeps on Rewarding

The 4L60E mods we have outlined above can ensure that whether you are a builder or a car fanatic with some level of experience, you can increase the horsepower and torque capacity of your car.

The result can be quite rewarding starting from a higher level of performance, and reduction in fuel consumption. If you want a more speedy ride, then these 4L60E transmission mods will surely suffice.