A short guide to 700-R4, 4L60E and 4L65E transmission
The ‘89 Turbo-Hydramatic TH700-R4, '92 4L60E, '05 4L65E, and the newer version of 4L70E were all designed so as to replace the much tried and tested TH350. These transmissions use lower gears ratios, are composed of a different valve body, and provide the much required fourth gear. In addition to all these, they are also equipped with a lock-up torque converter. The earlier 4L60E was fitted with a PWM torque converter lock-up control. Subsequently, this particular design was modified and a bolt-on bell housing design was made. The 2001 4L60E model featured sufficient enhancements to increase the capacity of the torque, and later on its name was changed to 4L65E. The major improvement of interest to enthusiasts is its 5-pinion planetary carrier. A number of pinion gears allowed loading to spread uniformly, ensuring that the 4L65E transmission is able to handle the torque better than its 4L60E sibling. In addition to that, a smoother 3-4 clutch, enhanced input shaft, and a large