Additional information has been developed to reduce high key lock or interior manual lock effort found on some 1986 S/T trucks equipped with power door locks. This additional information is intended to supplement the procedure for adjusting the power door lock motor found in Chevrolet Dealer Service Bulletin 86-44 dated March, 1986, (Group 10) and GMC Truck Service Bulletin 86-B- 44 dated March, 1986, (Group 2B).
The additional checks and procedures are as follows:
Trim Panel interference With Lock Rods
o Before removing the door trim panel, remove the two screws attaching the arm rest to the arm rest brackets (Figure No. 1).
o Gently pull the arm rest away from the door and operate the power door lock switch.
o If an improvement in door lock operation is noticed, replace the lock rod with new lock rod, P/N 15564849 LH or P/N 15564850, RH.
Foam Door insulator And Insulator Strips
o With the door trim panel removed, cut the foam door insulator and add tape strip to retain cut area as shown in Figure No. 2.
o Cut lock rod insulator strip in half lengthwise (Figure No. 3).
Power Window And Door Lock Switch Wiring
o Inspect for any power window and door lock switch wiring that may be contacting the door lock rods in the area behind the door lock lever. If contact exists, move the wiring so that it does not contact the door lock rods or manual lock barrel in housing assembly.
Power Door Lock Effod
o Remove power door lock thumb lever assembly (Figure No. 3) and check for binding or tightness of lock thumb lever. If binding or tightness exists, replace lever assembly, making sure thumb lever has no friction load on roll pin to housing, before new lever assembly is installed.
Door Lock Rod Guides
o Lubricate both lock rod guides as shown in Figure No. 3.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.