The loudest gen-four year — brakes, the 8-speed, and the AC all show up, but most of the expensive fixes are covered.

The 8-speed automatic on this year shudders and shakes and can hunt for gears; in the file it escalates to torque-converter failure and full rebuilds at 96,000, 140,900, and 155,000 miles, with metal shavings found in the pan. GM's first move is a fluid flush with a revised spec, which helps some trucks; when it doesn't, a rebuild is a several-thousand-dollar job. There is no blanket recall for this year's transmission. Test-drive for a shudder under light throttle and a hard 1–2 shift, and prefer a truck with a documented fluid service.

The gen-four Tahoe's air-conditioning condenser can crack from thermal cycling and lose refrigerant, killing the AC — the 'AC disaster' owners and mechanics describe. GM ran a Special Coverage (documents in the 10207716 family) for 2015–2017 Suburban and Tahoe covering an inspect-and-replace for 5 years or 60,000 miles. Most used trucks are now outside that window, so on a hot-climate example confirm the AC blows cold and ask whether the condenser was ever replaced — an out-of-coverage replacement is roughly a four-figure job.

Both V8s use Active Fuel Management (AFM) — cylinder deactivation that shuts off four cylinders to save fuel. The collapsible lifters that make it work can stick or fail, and a failed lifter chews up the camshaft, turning the repair into lifters plus a cam for several thousand dollars. Mechanics say it shows as a tick or tap, misfire codes, and lost power, and that gen-four AFM generally fails later than the gen-five DFM version. There's no recall — only a class action and reactive warranty repairs. Cold-start and listen for a valvetrain tick; a disabler tune (~$150) is cheap insurance against the deactivation cycling.

Two safety recalls on this year are must-verify. Recall 16V256 is a PARK-IT (do-not-drive) campaign for front upper control-arm welds that can let the arm separate and compromise steering — dealers replace both arms and realign, free. Recalls 16V651 and 17V437 address airbag sensing-and-diagnostic-module (SDM) software that could enter a self-test and fail to deploy the frontal airbags or pretensioners in a crash; the fix is a free reflash. Confirm all three are closed by VIN before you trust the truck.