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Crank walk – symptoms and fix on older engines?
1998 BMW 325i (M52) has slight axial play in crank- about 0.5mm measured at pulley. No clutch issues yet, but worried about thrust bearing wear. Common? Better to replace thrust washers now or wait for rebuild?

Crank walk (excess end float) on M52s often from thrust bearing failure- oil starvation or debris. Excessive play can damage crank flange or block thrust surfaces. If over spec (usually max 0.3-0.4mm), replace thrust bearings ASAP during next clutch job. I measured 0.6mm on mine- did thrust washers and checked crank flange for scoring. Got oversized thrust bearings from https://elartcom.eu/categories/engine-block-and-crankshaft-141 - they carry main bearing sets including thrust for BMW inline-6. Installed with proper preload, play back to 0.15mm. No more clunk on engagement. If doing clutch, do this- prevents bigger damage. Their category has good coverage for older BMW cranks and bearings.