The Speedmaster PCE676.1011 is a billet aluminum intermediate piston engineered specifically for the GM TH400 automatic transmission. Machined to a 0.250" oversize specification with a 5.867" diameter, this piston is designed to restore or upgrade clutch pack clamping performance in worn or bored TH400 housings, delivering a precise, reliable fit where a standard-size piston can no longer seal effectively.
Crafted from billet aluminum for improved strength and reduced weight compared to OEM-style components, this oversize intermediate piston is an ideal choice for performance rebuilds and hard-use applications on vehicles equipped with the GM TH400 transmission. It is a direct drop-in solution for TH400 units that have been bored 0.250" oversize, making it a go-to upgrade for transmission builders seeking quality and consistency.
