REDUCED HUB CAP RETENTION REPLACE WHEELS NUTS

VEHICLES AFFECTED: 1989 T TRUCKS

1989 T trucks equipped with steel wheels that were built between the following breakpoints may experience an inability to install the hub cap or reduced hub cap retention. This condition is due to an incorrect wheel nut being installed during assembly.

Moraine (2) GMC 1GTDT19ZOK2542853 thru 1GTDT19Z4K2543326

Chev 1GCCT19R3K2266440 thru 1GCCT14RXK2269696

Pontiac (0) GMC 1GKCT18ZIKO526321 thru 1GKCT18Z2KO526442

Chev 1GNCT18Z5KO189591 thru 1GNCT18ZOKOI90096

Shreveport (8) GMC 1GKCT18Z7K8536935 thru 1GKCT18Z2K8537989

Chev 1GNCT18Z9K8247848 thru 1GNCT18Z7K8251588

The hub caps on these vehicles are retained by an interference fit with the wheel nuts. If reduced retention is experienced, wheel nut P/N 14066920 (20 required per vehicle) should be installed on all four wheels and torqued to 140 N.m (100 lb/ft).

The correct wheel nut can be identified by a shoulder located between the tapered end and the hex fitting, and also it is approximately 1/4" taller than the incorrect wheel nut.

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.