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Sheared Crankshaft Sprocket Keys Found on Some GM 6.2L Diesel Engines
This bulletin affects 1982-1989 Light-Duty Trucks, Vans with 6.2L diesel engines
A new hardened washer, p/n 23504011, is availalbe for improved clamp
load of the crankshaft sprocket to the crankshaft by the crankshaft
bolt. Installation torques for the hardened washer have been increased
to 177 to 185 ft.lbs. (240 N.m /250 N.m).
Parts are currently available from GM and other suppliers should damper
loosening occur, resulting in the crankshaft sprocket shearing the lead
alignment key, repairs should be made using the new washer and torque
Examine the crankshaft sprocket, and assure before reassembly that
there is no damage to the keyway. During the assembly of the crankshaft
sprocket to the crankshaft, GM Goodwrench Thread Locker 272, p/n
12345492 or equivalent should be applied to the crankshaft post for 360
degrees at the rear' crankshaft key area only. Thread Locker 272
material should not be applied to the sprocket inside diameter (see Figure 1).
Some or all of the technical information was provided by the
Automotive Parts Remanufacturers Association (APRA). For more
information on technical bulletins available through APRA call
703-968-2772 or visit www.AutoBulletins.com.