4l60e Transmission

4L60E Shift Kit

So somebody suggested that you should install a 4L60E shift kit in your transmission, or perhaps that you’ve just heard someone talk about them before and you want to know what it is.  Well, this page will explain to you exactly what a shift kit is, and what you should look for in your 4L60E shift kit.

Shift kits are an aftermarket component that is specifically designed to be an upgrade for your transmission to change the shifting pattern.  In a normal automatic transmission it works by altering the shifting pattern to make it so there isn’t as much overlap in the shifts.  In normal operation an automatic transmission is engineered to provide a smooth shift.  In order to achieve this task, the transmission essentially will put itself in to two gears at once as it’s shifting.  This is known as a shift overlap.

A 4L60E shift kit is designed to alter this shifting pattern so that there isn’t as much overlap in the shifts.  The severity and aggressiveness of these kits varies.  Basically with a 4L60E shift kit installed the transmission will appear to bank in to gear, and feels like a more aggressive shift.  A traditional 460e shift kit works by re-valving the transmission.

However, before you run off and buy yourself a new shift kit, you really have to consider your application.  There are basically three different levels of shift kits.  A mild shift that just gives a firmer shift and is great for the highways, a moderate change which will have the tendency to raise the rpm range the transmission shifts at as well as making it more aggressive, and an aggressive setting that’s likely to make your tires chirp and yank your vehicle around that is designed for extreme off-roading or racing conditions.

A 4L60E shift kit can have the benefits of causing less wear on your bands and clutches (since there’s less overlap and intentional slippage) and help your transmission run cooler as well.  However, it can be harder on your other components of your transmission.  Imagine all of the gears in your transmission, and the difference it would make between a hard hit vs a soft release. Then look at the rest of your drivetrain. Can your axles, driveshaft, transfer case, etc. hold up to the significantly firmer shifts from your new 4L60E shift kit?

The most common 4L60E shift kit brands you will find include brand names such as Lokar, B&M, TCI Auto, and quite a few other brands. For street driving when you should aim for a mild-moderate 4L60E shift kit. However, before you install, make sure you have a pretty solid transmission. With a high horsepower engine, the more aggressive your 4L60E shift kit, the more strain it will put on your components. So don’t install an extremely aggressive shift kit in a stock transmission with a powerful engine, because your transmission will not hold up to the power.

The most aggressive 4L60E shift kit you can install is normally only reserved for either extreme 4wd situations, or racing. Since they kick in so suddenly when they shift, it can cause problems, especially when the roads are wet. So make sure that you don’t ever select something more than your setup can handle.