Chevrolet Silverado Transmission - Way Beyond The Power

GM recognized the 4L60E's sun shell as a weak link and slightly upgraded it for the stock 4L65s. FLT goes several steps further, modifying the legendary "Beast" sun shell to accept a Torrington roller bearing in place of the stock thrust bearing.

This cracked OEM sun shell was well on its way to failure, ultimately resulting in the loss of all gears except First. With a Beast sun shell, this sort of failure is eliminated.

Modified to accept the Torrington roller bearing, FLT's modified sun shell will spin effortlessly. This reduction in friction frees up power and increases durability.

The 4L60E's four pinion planetary gears are upgraded to a pair of new genuine GM five pinion parts. FLT has found GM planetaries to be the best available and avoids the inconsistent quality of used and imported parts.

On the left is a used pump housing showing signs of wear on the machined surfaces. FLT machines the pump surfaces to ensure a leak-free parallel surface.

On the top are the OEM sprag and low roller clutch; underneath are Borg-Warner parts FLT upgrades, too.

This close-up of the Borg-Warner sprag (left) shows its double cages and the larger cross-sectional area than the OEM sprag.

In FLT's experience, failure of the 3-4 clutch is the most common clutch failure. FLT addresses that by upgrading to an eight-clutch pack over the 4L60E's six-clutch pack.

For my blown 5.3L '01 4x4 applicataion, the Level 5's cryo-treated output shaft is plenty strong. Now for the guys who are combining power adders like getting stroked and blown, a stronger shaft is in order: FLT now offers a forged 4340 version to prevent unexpected shaft failure.

In blown applications using a vacuum modulater, a blower bypass check valve must be used to prevent boost pressure from entering the vacuum circuit.