Powerglide Deep Sump Cast Aluminum Transmission Pan

This is a cast aluminum deep sump pan for the GM aluminum Powerglide two-speed, Transmission Specialties part number 2553. It replaces the shallow stamped steel factory pan and comes with the drain plug, the mounting bolts, and the filter extension block you need to drop the stock pickup down into the added depth. Cast in the United States. Package weight is right at 10 pounds, so it is a substantial piece next to the thin OEM stamping.

Two things a deep aluminum pan actually fixes on a Powerglide. First, fluid volume: a stock shallow pan holds so little ATF that a hard pass or a long day of laps heats it fast, and hot fluid is what cooks the clutches and the direct drum bushing. More fluid in the sump means more thermal mass and a longer time to temperature. Second, heat rejection: the ribs cast into the outside of this pan give the aluminum far more surface area than a flat steel pan, and aluminum sheds heat to the air much better than steel does. The drain plug is the third thing you will appreciate the first time you change fluid without pulling eleven bolts and wearing the pan.

Installation is straightforward on the bench or under the car. Drain the old pan, unbolt it, pull the filter, and scrape both sealing surfaces clean. Bolt the supplied extension block onto the filter neck so the pickup sits at the correct height in the new deeper sump, then set the filter, lay the gasket, and run the pan bolts up in a criss-cross pattern to a light, even torque. Aluminum pans do not need to be gorilla tightened; overtorquing is the usual cause of a leak on one of these. Refill and check the level hot with the engine running in neutral, because a deep pan takes more fluid than the dipstick markings assume off a dry rebuild.