Door Locks - Binding or Sticking/Key Hard to Insert

BULLETIN NUMBER: 93-10A1-52

SECTION: 10A1

NUMBER: 3

CORPORATE REFERENCE NUMBER: 13107OR

DATE: March 1993

SUBJECT:
DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION)

MODELS:
1993 AND PRIOR TRUCKS - ALL MODELS

THIS BULLETIN CANCELS AND REPLACES GMC TRUCK BULLETIN # 92-10A1-29 DATED DECEMBER 1991. ALL COPIES OF 92-10A1-29 SHOULD BE DISCARDED.

Customer comments of binding/sticking door lock cylinders or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication.

The recommended materials for lubricating these components are (in order of preference):

- GM # 12345120 Multipurpose Lubricant (9 oz. spray) or # 12345121 (12 oz.).

- 5 W 30 Motor Oil

- GM # 1052276 or # 1052277 spray type Silicone 1.5 oz. or 12 oz. cans).

Penetrating oil type lubricants (such as GM # 1052949 or # 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubricating and eventually evaporate, leaving little or no lubricating material. However, if these materials are used to "unfreeze" or loosen lock cylinder components, refer to Steps 2 through 4 listed below for the proper methods of lubricating.

NOTE:
DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN BOUND.

If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multipurpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder.

Parts are currently available from GMSPO.

Frozen cylinders due to cold weather may be repaired using the following procedure:

1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces.
2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blowgun attachment.
3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder.
4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key.

Use applicable Labor Time Number and Time allowance.