Service bulletins for the 2021 GMC Sierra
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.
1649 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
By topic
Only bulletins with component: Transfer case are shown. Show all
| PIP5810A | 2022-10-17. Service bulletin. POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE). This Preliminary information communicates that the tool for the HD transfer cases to install the input seal during a repair is incorrect and a new tool is in development. |
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| N212336800 | 2021-08-09. Service bulletin. EQUIPMENT:ELECTRICAL; POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE); EQUIPMENT. Service Update. On certain vehicles, the thrust washer was not installed on the transfer case reduction carrier assembly. Dealers are to replace the transfer case. |
| 19NA136 | 2021-02-01. Service bulletin. PARKING BRAKE; EQUIPMENT; POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE). This service bulletin provides a diagnostic procedure to aid in correcting a customer concern of a Howling, Whining/Whirring Noise, Shudder/Vibration and/or Grinding Noise While in 4HI, 4HI Auto and/or During Parking Lot Maneuvers in Auto Mode. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.