Original BMW Crankshaft Pulley Bolt for 3 Series, 5 Series, M3, X3, X5, Z3, and Z4 (1991–2006)

Torqued to 410 Nm, this Original BMW hex bolt secures the crankshaft pulley and harmonic balancer to the crankshaft on M50, M52, M54, M56, S50, and S52 engines in the BMW 3 Series, 5 Series, M3, X3, X5, Z3, and Z4. A crankshaft pulley bolt carries the full clamping load that keeps the balancer locked to the crank snout, so it works harder than almost any other fastener on the front of the engine. BMW calls it a hex bolt, and each bolt weighs 314 g (0.7 lb). One is required per car. BMW TIS classes it as a one-time-use bolt that must be replaced whenever it is removed.

Original BMW Parts carry a 24-month parts warranty.

This number replaces the earlier 11-21-7-749-856. BMW notes that the change is not interchangeable retrospectively. BMW has supplied this bolt since September 1989, so it covers a long run of engines, from the E34 and E36 through the E46, E39, E53, and E83, as well as both generations of roadster. Because of that spread, confirm your engine code rather than going by chassis alone.

Technical Details

• Manufacturer: BMW (Original BMW part)
• Part number: 11-21-1-720-633
• Supersedes: 11-21-7-749-856
• BMW name: hex bolt
• Weight: 314 g (0.7 lb)
• Production start: September 1989
• Quantity: one per car
• Made in Germany
• Warranty: 24-month parts warranty

Installation & Tuning Notes

Tightening this bolt to 410 Nm requires a counter hold to keep the crankshaft from turning. BMW special tools 118 190 and 118 200 serve that purpose.

Common Questions

Can I reuse my old crankshaft pulley bolt?
No. BMW TIS treats it as a one-time-use bolt and calls for a new one.

How many do I need?
One per car.

Fitment & Compatibility

Confirm your model year and submodel against the table below before ordering. PMB Performance can confirm this against your VIN, backed by more than 20 years of parts and fitment work.