GMC Trucksrepair & diagnostics
GMC medium-duty trucks (TopKick, Kodiak, and older W-series) run a mix of Duramax, Caterpillar, and gas engines. We handle GMC electrical and charging faults, no-starts, and air brake service.
Shop & mobile service for GMC Trucks
Connect the right laptop, pull active and inactive codes, and read live data before recommending parts.
Forced (parked) regens, SCR/DEF dosing faults, NOx sensor diagnosis, and derate clearing.
Slack adjusters, chambers, relay valves, drums, linings, and ABS blink-code reading.
Alternators, batteries, parasitic draws, 7-way, and crank/no-start diagnosis.
Air ride ride height, air bags, leveling valves, and walking-beam service.
Preventative maintenance A/B/C and annual DOT inspections that leave you compliant.
Commercial tire sales, mounting, balancing, wheel seals, bearings, and hubs.
Lights, brakes, suspension, landing gear, doors, and reefer refrigeration troubleshooting.
The faults we see most
Alternator failures, parasitic draws, and ground faults on GMC medium-duty chassis.
Crank/no-start and no-crank paths — fuel, cranking, and ECM command.
Air brake and foundation brake service for GMC medium-duty.
GMC Trucks engine platforms
We connect the right diagnostic laptop for each engine platform GMC Trucks runs, pull the fault codes, and read live data before recommending a single part. Below are the engines we service on GMC Trucks.
Read the diagnostic path
MTG Shops does not perform engine overhauls or major component rebuilds in-house. We have quality partners in every market who specialize in GMC Trucks overhauls and in-frame / out-of-frame rebuilds. We handle the diagnosis, get the truck to the right specialist, and coordinate the handoff. You get an honest answer about what we fix and what goes to a trusted partner.
Get a bay time and a straight estimate.