TSB 667406 — GMC Service bulletin

667406 is a service bulletin on file with NHTSA for the GMC Yukon, 1992–1994 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.

What the bulletin says. TRANSFER CASE HOPS OUT OF 4-HIGH, OR NO DRIVE IN 2 OR 4-HIGH RANGES AND/OR GRINDING NOISE (INSTALL MAINSHAFT/RANGE HUB KIT)

NHTSA's own summary of the document, quoted from the public manufacturer-communications file.

1Document filed
1Vehicle named
3Model years

Vehicles and model years 667406 names

VehicleModel years
GMC Yukon 1992, 1993, 1994

Every document filed under 667406

Document IDFiledType
667406 December 1, 1996 Service bulletin

What 667406 covers

Transmission & drivetrain — the component vocabulary NHTSA files this communication under.

← All GMC Yukon TSB years TSB lookup by model

Questions buyers ask

What is TSB 667406?

667406 is a service bulletin filed with NHTSA by GMC, covering the GMC Yukon across the 1992–1994 model years. NHTSA's summary reads: TRANSFER CASE HOPS OUT OF 4-HIGH, OR NO DRIVE IN 2 OR 4-HIGH RANGES AND/OR GRINDING NOISE (INSTALL MAINSHAFT/RANGE HUB KIT)

Which vehicles does 667406 cover?

NHTSA's file names GMC Yukon (1992–1994). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.

Is TSB 667406 a recall, and is the repair free?

No. 667406 is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.

How do I get the full text of 667406?

Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under 667406, its date, and NHTSA's own summary from the public file.

Data updated 2026-08-20 from NHTSA's public records

Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under 667406. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.