Campaign - Ball Joints/Alignment: Overview
91chevy16
GMC NUMBER: 90-3C-60(B)
GROUP: 3C Front Suspension
DATE: August, 1991
SUBJECT: SPECIAL POLICY ADJUSTMENT - GREASEABLE UPPER & LOWER CONTROL ARM BALL JOINTS AND FRONT END ALIGNMENT PARTS KIT
MODELS: 1988-90 C/K TRUCKS
THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN 90-3C-60(A) DATED DECEMBER, 1990 TO REVISE THE SERVICE PROCEDURE AND THE LABOR TIMES. ALL COPIES OF 90-3C-60(A) SHOULD BE DISCARDED.
REVISIONS TO THIS BULLETIN INCLUDE ADDITION OF A REQUIREMENT TO CHECK THE CONDITION OF 1990 MODEL YEAR C/K MAINTENANCE-FREE BALL JOINTS BEFORE REPLACEMENT, ELIMINATION OF CASTER/CAMBER ALIGNMENT AND ADDITION OF TOE-IN ALIGNMENT.
Ball Joints:
A contaminated front suspension ball joint can cause squeaking while turning and/or require more frequent steering input while driving down the road. Contamination could also cause a ball joint to wear out and eventually to separate. 1988-1989 Some of the maintenance-free front suspension ball joints used on 1988 and 1989 model C/K trucks have experienced contamination.
1990
Later design maintenance-free ball joints were used in early 1990 model C truck front suspension upper control arms and K truck front suspension upper and lower control arms. Those maintenance-free front suspension ball joints used in the 1990 model C/K trucks incorporated two significant design changes that greatly reduce the possibility of contamination.
An enhancement was made at the neck of the ball stud by changing the material of the seal insert to glass-filled nylon for greater stiffness and less shrinkage when cold. In addition, the composition of the seal was changed to make it more flexible in cold weather.
Since the first publication of the Special Policy Adjustment Bulletin, stringent lab testing, proving ground durability tests and a fleet field test have demonstrated the durability of the 1990 model C/K maintenance-free front suspension ball joints.
Therefore to determine whether a customer complaint is attributable to contamination of a maintenance-free ball joint on a 1990 model truck, do not replace any such ball joint unless the ball joint wear check included in this bulletin indicates over 1 mm (0.040 inch) of lash.
Greaseable ball joints were also used in 1990 model year production as follows since:
start of production on the C truck front suspension lower control arms;
interim production on the C truck front suspension upper control arms; and
interim production on the K truck front suspension upper and lower control arms.
The greaseable style ball joint incorporates a zerk fitting to facilitate maintenance and is designed to allow grease to purge at the interface of the rubber dust cover and the ball joint shell (or socket).
Figure 1:
Replacement Ball Joints
Greaseable ball joints should be used as replacements for contaminated maintenance-free ball joints. Since it is important to lubricate the greaseable ball joint, customers must be given the information slip, shown in figure 1, which explains the greaseable ball joint maintenance requirements. This slip is packaged ineach service ball joint kit.
Front Wheel Caster/Camber Alignment Parts Kit:
The 1988-90 C/K trucks incorporate a front suspension feature designed to improve the vehicle's ability to maintain front wheel caster/camber alignment.
The front wheel alignment set by the assembly plant will not change and should not need adjustment except in cases where accident or road hazard damage has occurred. Through the listed VIN breakpoints, in customer pay situations if caster/camber alignment was performed, the customer was also charged for the required alignment parts kit. Due to the cost of the parts kit, the charge for a wheel alignment would not be competitive in today's marketplace. In view of this, GMC Truck has issued a special policy to cover the cost of the caster/camber alignment parts kit but not the installation cost. This kit is included in vehicles currently being produced.
VEHICLES INVOLVED - BALL JOINTS
YEAR MODEL PLANT FROM THROUGH COMPONENTS INVOLVED
1988 C/K Ft. Wayne (Z) SOP EOP All Ball Joints
1988 C/K Oshawa (1) SOP EOP All Ball Joints
1988 C/K Pontiac (E) SOP EOP All Ball Joints
1989 C/K Ft. Wayne (Z) SOP EOP All Ball Joints
1989 C/K Oshawa (1) SOP EOP All Ball Joints
1989 C/K Pontiac (E) SOP EOP All Ball Joints
1990 C Ft. Wayne (Z) SOP LZ531411 Upper Ball Joints
1990 K Ft. Wayne (Z) SOP LZ532770 All Ball Joints
1990 C Oshawa (1) SOP L1539478 Upper Ball Joints
1990 K Oshawa (1) SOP L1539477 All Ball Joints
1990 C Pontiac (E) SOP LE530629 Upper Ball Joints
1990 K Pontiac (E) SOP LE530628 All Ball Joints
VEHICLES INVOLVED - ALIGNMENT PARTS KIT
YEAR MODEL PLANT FROM THROUGH
1988 C/K Ft. Wayne (Z) SOP EOP
1988 C/K Oshawa (1) SOP EOP
1988 C/K Pontiac (E) SOP EOP
1989 C/K Ft. Wayne (Z) SOP EOP
1989 C/K Oshawa (1) SOP EOP
1989 C/K Pontiac (E) SOP EOP
1990 C/K Ft. Wayne (Z) SOP LZ525988
1990 C/K Oshawa (1) SOP L1536879
1990 C/K Pontiac (E) SOP LE530905