F 250 2WD Pickup V8-7.3L DSL (1990)
Technical Service Bulletin # 921A9
Date: 920126
Driveline - Modification Guidelines
Article No.
92-1A-9
01/26/92
TRANSMISSlON - E40D AUTOMATIC - MEASURING FOR CORRECT DRIVELINE ANGLE
LIGHT TRUCK:
1989 and after BRONCO, ECONOLINE, F SUPER DUTY, F-150-350 SERIES
ISSUE:
Qualified Vehicle Modifier (QVM) Bulletin Number 14 provided guidelines for modifying light truck drivelines to help ensure proper
driveline integrity. The bulletin is printed here as an added aid to the service technician.
ACTION:
Refer to the following pages.
Guidelines For Modifying Light Truck Drivelines
Improper driveline modifications were found to influence recent service claims for transmission damage, premature wear-out of U-joints, and noise and
vibration. When modifying a driveline use the following guidelines to help ensure proper driveline integrity. Although these guidelines cover the most
immediate concerns, they are not comprehensive. The reader is encouraged to further consult the references listed at the end of this bulletin.
In general, limit the amount of balance weight to approximately 3 ounces or less at each end of a shaft. Excessive weight required to balance indicates
that the shaft is likely to be distorted beyond the runout specifications and should not be used. Compare the runout of the shaft against the following
specifications to determine whether a shaft is worth balancing.
A list entitied "Things-Gone-Wrong" follows. This list contains the "things-gone-wrong" commonly found on vehicles with modified drivelines. Vehicle
modifiers are encouraged to use this list to quickly identify problem areas in their build process.
