Timing Chain Tensioning Rail - Modified
90bmw17 Group 11 EngineBulletin Number 11 10 90 (3144)
Woodcllff Lake, NJ October 1990 Service Engineering
SUBJECT: Modified Timing Chain Tensioning Rail
MODEL: E31, E32 (with M70 engine)
Situation: A modified timing chain tensioning rail has been phased into production as of mid-June 1990. The new style timing chain tensioning rail incorporates a roller (sprocket) in addition to the plastic-coated sliding surface. The new configuration reduces the relatively high friction loads in cold operating conditions and thus reduces wear.
Installation
Note: The timing chain adjustment distance has been reduced by 1 mm to
5 +/- 0.5 mm due to the use of the new style timing chain tensioning rail. See repair manual for details on adjusting bming chain tension.
Parts
Information: The new tensioning rail (P/N 11 31 1 725 682) can be installed retroactively whenever engine repairs are performed. Upon depletion of the current parts inventory the old part number will be superseded to the new part number, 11 31 1 725 682.