Preparing A 4L85e Transmission For Towing
The 4L85E is built and designed by the popular General Motors, with a four-speed automatic transmission. It comes from the same group of transmission with the 4L80E. They are both heavy duty transmissions, with the 4L80E rated to carry over 440 lb-ft of torque. While the 4L85E, on the other hand, is rated slightly higher at about 460 lb-ft.
These transmissions are based on an original heavy-duty TH400 three-speed transmitter. General Motors made use of the 4L85E in some of the vehicles, including the Chevy Express, Chevy Avalanche, the Chevy Express van, GMC Yukon XL, and the GMC Savana. Also, it was used in the Chevrolet Suburban. Here we will suggest how to prepare the 4L85E transmission for towing.
The primary challenge you are probably going to experience when towing is the creation of excessive and damaging heat. Typically, your 4L85E transmission is supposed to operate at the highest temperature of about 200°. For every 20° you go beyond this limit, you risk reducing the lifespan of the transmitter by a factor of two.
Getting Rid Of Excessive Heat
The best way to get rid of the excessive heat generated from towing in your transmission is to put in an aftermarket transmission cooler to support the factory cooler. You may want to buy the largest cooler that's going to befit the constraints of the Suburban. It must be installed in a position that will get access to adequate and sufficient airflow during the movement of your vehicle. If that is impossible, consider getting a cooler that has its in-built electric fan. This will help you to mount your cooler almost anywhere you'd like to.
Another good method to get your 4L65E ready for towing is by the installation of a shift kit. A shift kit key has many advantages. First, the kit will come along with components and modifications that raise the line pressure of the transmission. This will enhance the clamping force on the clutches and band and also help to prevent them from ever slipping under the heavy load.
Secondly, a shift kit gives you more control manually to your transmission, giving you the chance to downshift to a lesser gear at a higher speed. This will, in turn, slow down the vehicle speed through the engine braking, preventing you from wearing your brakes out. Lastly, the shift kit will bring down the time it takes for your clutch packs to apply entirely. This will reduce both excessive wear and heat.
With the proper maintenance and care, the 4L85E transmission in your Suburban will serve you very well, more than you expected, for a very long time. Just like everything else, it requires the proper maintenance and care. Be sure enough to get your transmission on a scheduled service plan regularly. Notwithstanding, Chevy recommended that you can go much longer in between the services. It is recommended that you get your transmission serviced every 24000 miles, especially if you're always towing a heavy load. This is a way to a happy, and safe towing with your 4L85E transmission Chevrolet Suburban.