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Service bulletins for the 1998 GMC T-Series

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

70 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Bulletins, newest first
990603004A1999-11-02. Service bulletin. ELECTRICAL SYSTEM. SOME CUSTOMERS MAY COMMENT ABOUT THE HORN SOUNDING AND A NO START CONDITION DUE TO WATER INTRUSION INTO THE ACCESSORY WIRING JUNCTION BLOCK. *TT
9907290041999-09-29. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION. SOME MEDIUM DUTY MODELS EQUIPPED WITH MANUAL TRANSMISSIONS MAY EXHIBIT A HIGH SHIFT EFFORT OR HARD SHIFTING CONDITION. *TT
9908500141999-09-29. Service bulletin. SEATS:FRONT ASSEMBLY:POWER ADJUST. CONCERNS WITH DRIVER / PASSENGER SEAT ADJUSTER SWITCH BEZEL AT SEAT WILL NOT STAY FASTENED. *TT
9907300131999-09-29. Service bulletin. UNKNOWN OR OTHER. SOME CUSTOMERS MAY COMMENT ABOUT THE SERVICE ENGINE SOON LIGHT ILLUMINATING. *TT
9906030041999-09-01. Service bulletin. ELECTRICAL SYSTEM. CUSTOMER MAY COMPLAIN ABOUT HORN SOUNDING, NO START DUE TO WATER INTRUSION INTO ACCESSORY WIRING JUNCTION BLOCK. *TT
990232004A1999-08-26. Service bulletin. STEERING:HYDRAULIC POWER ASSIST:PUMP. SOME OWNERS / OPERATORS OF MEDIUM DUTY MODELS MAY COMMEND ABOUT WATER ENTERING THE POWER STEERING RESERVOIR AND CONTAMINATING THE POWER STEERING FLUID. *TT
9908420021999-08-06. Service bulletin. EXTERIOR LIGHTING:HEADLIGHTS. SOME CUSTOMERS MAY COMPLAIN THAT THE DAYTIME RUNNING LIGHTS ARE INOPERATIVE. *TT
9902320041999-08-06. Service bulletin. STEERING:HYDRAULIC POWER ASSIST:PUMP. SOME MEDIUM DUTY MODELS MAY HAVE WATER INTRUSION INTO THE POWER STEERING RESERVOIR. *TT
9908490071999-08-06. Service bulletin. FUEL SYSTEM, OTHER. SOME VEHICLES BUILT WITHIN VIN BREAKPOINTS XJ105482 AND XJ510031 MAY EXHIBIT INACCURATE FUEL GUAGE READINGS, VEHICLE RUNS OUT OF FUEL, OR FUEL GAUGE REGISTERS FULL BUT MAY STILL ADD FUEL. *TT
866503A1999-03-08. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE. SUBJECT REGARDING OBD II DIAGNOSTIC TROUBLE CODE (DTC) P1404 (REFLASH VCM). *YC
8674041999-03-08. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. COMMENTS ABOUT A LOW TRANSMISSION FLUID LEVEL OR THAT THE TRANSFER CASE FLUID IS OVERFILLED. *YC
8632101999-02-01. Service bulletin. SUSPENSION:FRONT. SOME OPERATORS MAY COMMENT ABOUT A FRONT END SHKE OR A VIBRATION IN THE FRONT END. *YC
8632081999-01-11. Service bulletin. SUSPENSION:FRONT. COMMENTS ABOUT A SHAKE OR VIBRATION IN THE FRONT END OF THE VEHICLE. *YC
980531999-01-06. Service bulletin. SUSPENSION:REAR. SOME VEHICLES EXHIBIT AN OVERHEAT CONDITION OF THE REAR AXLE OIL, RESULTING IN A NOTICEABLE
980531999-01-05. Service bulletin. SUSPENSION:REAR. SOME VEHCLES MAY EXPERIENCE REAR AXLE OIL LEVEL LOW. *YC
988612081998-08-28. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. COMMENTS THAT THE HVAC BLOWER FAN RUNS CONTINUOUSLY WITH IGNITION OFF. *YC
987760021998-08-28. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE. SUBJECT ON ACCESSORY DRIVE BELT NOISE DUE TO POWER STEERING PUMP PULLEY MISALIGNMENT. *YC
988371101998-08-04. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION. TECHNICIANS MAY EXPERIENCE DIFFICULTY IN REMOVING THE CONNECTORS FROM THE PARK/NEUTRAL POSITION SWITCH, USUALLY WHEN TRYING TO REMOVE THE SWITCH DURING TRANSMISSION SERVICE. *YC
988643061998-08-03. Service bulletin. POWER TRAIN:AXLE ASSEMBLY. COMMENTS ABOUT FLUID LEAKING ONTO THE GROUND NEAR THE FRONT WHEELS OR FRONT ENGINE AREA OR LEAKING ONTO THE SURROUNDING COMPONENTS. *YC
7682101998-04-29. Service bulletin. EXTERIOR LIGHTING:HEADLIGHTS. CONDITION WITH HEADLAMP BOOT LOOSE. *YC

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.