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?
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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.