Transmission Rebuild: How To Convert Your 4l60e Into 4l65e Specifics




The used 4L60E transmission has been an essential part of the General's range of transmissions. The 4L60E trans, a successor to the 700R4 is a model with a long history backing up several powerful motors. GM first began using 4L60E rear-wheel drive cars in 1994. Demand for performance grew as did the need for a new engine. The 4L65E was released. Although the platform was the identical as the 60 and the 4L65E had a few modifications. The 4L60E is equipped with four-pinion planetary carriers. These carriers are rated to 360 ft. lbs of torque. The 4L65E uses 5-pinion planetaries together with an input shaft that is hardened, that boosted performance to the level of 380 ft.lbs. The best part of this is that the 5-lug parts can be easily converted into the 4L60E and give you the option of upgrading your current tranny, without needing to purchase the new model.

Removing the planet's carriers requires the complete teardown. This isn't the best time to begin if you've never done it before. It's not the most difficult thing to build but it is certainly not the easiest. To finish the job properly it is necessary to have some tools that are specialized. A Rear Clutch Spring Compressor Universal Pump Remover, Front Pump Alignment Band, Turbine Shaft Installer and a Teflon Stator Shaft Installer are all required to take apart and rebuild the 4L60E transmission.

The 4L60E automatic transmission, an electronic controlled unit, is notated with the "E" after the name. In 1993, when the 4L60E was first introduced, the 700R4 was renamed 4L60. This is important as while they share a few parts, they are different transmissions. GM changed the 4L60E lockup circuit into a Pulse Width Modulated in 1995. This lockup circuit allows for a smoother transition because it pulses the signal rather than all simultaneously. The pump will bear an "PWM" label on it if it is a PWM-type tranny. It is vital to know that the tranny type must be compatible with the computer in the vehicle.

In this build we made use of several kits. We utilized a Trans-Go Reprogramming Tool and the Sonnax 4th-gear "Super Hold” Servo, a Raybestos Z-pack clutch set, and Red Eagle Red-Oxide Clutches. We chosen the clutch kit making use of the Z-pack to make the 3-4 gear clutches. They're specifically designed to not bow and come with greater holding power. The Red-Oxide clutches have better hold for the first 1-2.



A sturdy sun gear is an additional essential element for any high-performance 4L60E transmission vehicle. It is crucial in reverse and 2nd application. The standard components tend to strip the gears at the neck during high-performance applications. The market responded with the "Beast" sun shell. This unit is made of a thicker overall material and also comes with a new thrust washer.

Valve Body

The valve body is an essential step in modifying the 4L60E for use in performance applications. The Trans-Go Reprogramming Kit comes with everything required to repair the valve body and to make it compatible for high horsepower. Before the valve body is able to be bolted on, the separator plate needs to be changed.

The separator plate sits between the transmission body and valve body. It is a thin piece of sheet metal that has been cut with 50 or 60 holes within it. The instructions for reprogramming tools provide 10 holes that have to be made. These are the relief ports and the pressure ports. They can be opened up to an maximum of.093" which increases the firmness of the shift and also adjusts each shift's timing. Although it is not included in the kit instructions, we suggest drilling the solenoid B and B ports to .040". This can slightly extend the duration of the shift, and makes it more enjoyable to shift.

The valve body is upgraded with an updated spring and valve, which alters the converter regulator and isolator to permit the use of any type of torque converter lockup plate.