Clutch Disc Alignment Tool
A clutch kit typically contains a plastic clutch alignment tool. It has the same dimensions as the transmission's input shaft. It has splines that match the splines on the clutch disc and a pilot that fits into the pilot bearing. It aligns the clutch disc to the flywheel and the pressure plate before torquing its cover.
The clutch pilot bearing is a ball, roller, or brass bushing that centers the transmission's input shaft in the crankshaft flange. After assembling the clutch disc and pressure plate to the flywheel, slide the alignment tool through the pressure plate's diaphragm and the clutch disc's splines into the pilot bearing.
Remove and replace the pressure plate's bolts according to specifications in a criss-cross pattern. Make sure the tool and clutch disc are centered while torquing the bolts. Ideally, the transmission input shaft will slide through the clutch splines and into the pilot bearing. It usually takes a bit of wiggling around to get it aligned and then the transmission aligned with the engine.