BMW SAC Clutch Alignment Tool Kit, 16-Piece Mandrel Set

A self-adjusting clutch (SAC) like the ones BMW uses on its manual gearboxes has to go on with the disc dead center on the flywheel, or the gearbox input shaft will not slide into the pilot bearing and the disc hub can get damaged when the bolts are drawn down. This kit gives you six stepped mandrels, each with a center bolt, so you can pick the one that matches the pilot bore and the disc spline and hold the disc in place while the pressure plate is torqued.

The pilot ends step down to 22, 25, 27 and 32 mm, with bodies from 35 to 75 mm long, which covers the common BMW SAC disc and pilot combinations. The center bolt lets you snug the mandrel in so it does not walk while you start the pressure plate bolts. The kit works on a brand-new SAC assembly and on a previously pre-tensioned one being reinstalled after the adjuster has been reset.

On the bench: slide the disc onto the mandrel with the correct face toward the flywheel, seat the pilot end in the crank bearing, start the pressure plate bolts by hand, then draw them down evenly in a cross pattern before pulling the mandrel out. If the mandrel does not come out freely, the disc has shifted and the bolts need to be backed off and re-centered before the gearbox goes up.