This starter bushing supports the pinion shaft inside the starter motor housing, maintaining correct gear engagement with the flywheel ring gear during cranking. It acts as a plain bearing that absorbs radial loads each time the starter is energized. Wear on the bushing bore allows the pinion to wobble, which produces a grinding noise and can damage both the starter drive and the flywheel ring teeth. The bushing is machined to the original shaft clearance specified by AGCO, so no shimming or reaming is required during replacement. On installation, ensure the bushing is fully seated in the housing bore and lubricate the inner surface before fitting the shaft.