700R4/4L60E 4-Pin Front and Rear Planet Set with HD Shell

Front and rear planetary carrier set for the GM 700R4, 4L60 and 4L60E, shipped as a complete assembly with a new heavy-duty reaction sun shell, thrust washers and bearings already installed. The front planet is the 4-pinion design and is machined to run with either the bearing-style or thrust-washer-style front ring gear, so it drops into both the early 700R4/4L60 cases and the later 4L60E without you having to identify which ring gear setup the core came with. Manufacturer part number ER74583K.

The reaction sun shell is the reason most of these units come apart. The shell carries torque between the reaction sun gear and the input drum, and the splines wear round on the sun gear end. As they go, you lose second and fourth gear and the transmission slips into what feels like a neutral condition on the 1-2 shift, or reverse quits entirely. A stock stamped shell that has been through one heat cycle too many will crack around the spline teeth even if it still measures acceptable on the bench. Replacing the shell alone without inspecting the planets is why the same unit comes back.

On the bench, pull the input drum and sun gear, check the reaction sun gear splines against the new shell for slop, then set the front and rear planets in place and verify end play before you button up the case. Because the washers and bearings ship installed, you are not sorting loose thrust washers by thickness during assembly. Inspect the planet pinion gears for pitting and the pinion pin ends for walking before reuse of any surrounding hard parts.

Fits 700R4, 4L60 and 4L60E units. This is a rebuilt and inspected assembly, not a bag of loose components.