Adjusting Pulley

All E9X M3’s use p/n 11287838194 as the tensioner arm on the alternator and water pump drive site. It uses a pulley marked F-233151.06 which is sold on its own as INA 5320342100 which cross-references to a BMW idler pulley (OE# 11281440237). Instead of replacing the entire tensioner pulley assembly (pulley + cast lever arm the hydraulic damper attached to), you can just replace the pulley which is a massive cost saving.

To install this pulley you will need to discard the included backing plate and mounting screw as it's not compatible with the tensioner arm for the S65 V8. You will reuse the original mounting bolt that held the original pulley to the tensioner arm. The tensioner pulley as sold by BMW should only be replaced as an assembly if the threads for mounting the hydraulic damper are damaged or the pivot point bushings are worn (both of which are unlikely scenarios under normal circumstances).

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