A solid mid-generation truck with two expensive habits — buy one that's had the transmission and lifters checked, not promised.

2016 is roughly when the 8-speed 8L90 arrived in the Silverado, and it brought a signature shudder — a shake you feel through the truck — plus harsh, clunky shifts. GM's fix was a transmission fluid flush with a revised fluid, which helps many trucks; mechanics also point to the older 6L80's high torque-converter failure rate. When the transmission or converter actually lets go, a rebuild or replacement is $4,000–$6,000. On a test drive, feel for shudder at light throttle around 25–45 mph and any lurch from a stop — a fluid service can mask early symptoms, so weight the maintenance records.

On trucks with the power sliding rear window, GM documented "areas of high electrical resistance on the rear defroster circuit," caused partly by the mechanical stress of opening and closing the window, debris getting in, and use of the defroster. GM's own wording is that over time the heat "could melt the areas surrounding the circuit" and, in rare instances, "cause a non-propagating fire." The Customer Satisfaction Program covers the buss bar and contact covers, and the glass itself where it has already been damaged. The program's stated scope runs 2014 through 2019, so this year sits inside it. Establish whether the truck has the power sliding window, run the defroster and cycle the window through its full travel while watching for anything that smells hot, and check the program by VIN.

GM's third-gen trucks are notorious for A/C condensers that crack and leak, and there was never a recall — if yours goes, you pay, typically around $1,000, and the compressor can fail too. It's common enough that mechanics treat a working, recently serviced A/C as a checkmark, not a given. A quick used-buying tell: an upgraded replacement condenser is marked in the top-right corner. Test the A/C cold on the drive, especially on a hot day.

The engine-mounted mechanical vacuum pump that powers brake assist can lose output over time, giving a harder pedal and longer stopping distances — the subject of recall 19V645 (2014–2018) and a related GM Special Coverage. GM notes that skipped oil changes contribute. A 'Service brake assist' message and a firmer-than-normal pedal are the tells; the remedy (reprogram or pump replacement) is covered under the recall/coverage, so verify by VIN it was addressed.

The factory frame coating is a wax that hardens and flakes with age, and the area around the fuel tank rusts badly in salt-belt trucks. Mechanics recommend fluid-film treatment yearly to arrest it. On any Northern truck, inspect the frame rails, crossmembers, and fuel-tank straps closely — surface scale is normal at this age, but flaking scale and thinning metal are not.