T-0151 Rear Clutch Spring Compressor - 4L60E/700R4 Low & Reverse

This is the T-0151 rear clutch spring compressor, the tool you reach for when you have the case flipped over and need to get the low and reverse clutch piston out. The return spring sits under a retainer held by a snap ring, and it is under enough load that trying to pry the ring out cold is how techs lose fingers and eyes. This tool clamps down on the retainer, pushes the spring back far enough to expose the snap ring groove, and holds it there while you work the ring out.

It fits the GM Turbo Hydramatic and later overdrive families that all share the same rear low/reverse setup: 250, 250C, 350, 350C, 700R4, 4L60, 4L60-E, 4L65E, 4L70, 4L70E, and 4T80-E. The legs engage the lugs cast into the case, so the load is carried by the case instead of by a pried edge. Wind the center screw down, snap ring comes out, back the screw off, and the retainer and spring lift straight out.

On reassembly you run it in reverse: set the spring and retainer, compress until the groove clears, drop the snap ring in, and confirm it seated all the way around before you release. The body is carbon steel. It is a specialty tool that gets a rebuild apart in a couple of minutes instead of fighting a spring under load the whole way. Bench-mounting the base or clamping it in a vise makes it steadier on the deeper drums.