Pull a driveshaft with the transmission still full and the fluid follows it out onto the floor. A tailshaft plug slips into the output housing in its place and seals it, which is what makes it possible to move or store a car with the driveshaft out without draining the transmission first.

FTI Performance F12005 Transmission Tailshaft Plug Features:

• Fits GM Powerglide, TH350 and 200-4R transmissions.
• 27 spline.
• Seals the tailshaft housing when the driveshaft is removed.
• Moulded plastic in red so it is not left in by mistake.
• Sold individually.