Javen Coughlin’s first car was a 1966 El Camino, which he restored at 16. He trained at Universal Technical Institute, became ASE Certified, earned his GM certifications and worked at General Motors and Buick dealerships. In 2021 he started Floorjack Auto Repair. The shop works on all makes, with the most depth on GM, Ford and Ram, and GM is the make Javen trained on.
The GM vehicles we work on
The GM vehicles that come through include Silverado and Sierra pickups, the 2500 and 3500 HD among them, and Tahoe, Yukon and Suburban. Equinox and Malibu come in as daily drivers, and so do Buick and Cadillac models. Each one gets the same process: find the fault, explain it, and give you the price before any work starts.
A Silverado 2500 HD with a steering wobble
A 2019 Chevrolet Silverado 2500 HD came in with a steering wheel that shook after bumps and took almost 30 seconds to settle. Javen found play in the center link and the idler arm. On this truck the steering box swings a pitman arm that moves the center link, the idler arm holds up the other end, and the tie rods run from the center link out to each front wheel. When those joints get loose, a bump can start the front wheels shaking until it dies out on its own.
He replaced the center link and the idler arm, then did an alignment, since an alignment won’t hold while the linkage is loose. The truck got an oil change and a new air filter on the same visit.
Big tires and heavy front ends put more load on steering joints. If your HD wanders on the freeway or shakes after a bump, the linkage is one of the first places to look. Steering and suspension work is part of our brake and chassis service.
GM problems worth knowing about
The 6.2L V8 engine recall
GM recall 25V-274 covers certain 2021 to 2024 Silverado 1500, Sierra 1500, Tahoe, Suburban, Yukon, Yukon XL, Escalade and Escalade ESV models with the 6.2L V8 (RPO L87). The recall is for crankshaft and connecting rod problems that can lead to engine failure. Recall work is free at a GM dealer, so put your VIN into NHTSA’s recall lookup before you pay anyone. If your truck isn’t covered and the engine is making noise, bring it here for a diagnosis.
Eight-speed shudder
GM service bulletin 18-NA-355 covers torque converter shudder in the 8L45 and 8L90 eight-speed automatics used in many 2015 to 2019 Chevrolet, GMC and Cadillac models. The bulletin tests for it at about 40 to 55 mph on light throttle, where it can feel like driving over rumble strips.
Check engine lights
A code tells us which system reported a fault. It doesn’t say which part failed. Finding the part is the diagnosis, and you get the price once we know. More on that is on our check engine light page.
When a GM engine or transmission needs replacing
Diagnosis, removal and installation all happen in our shop. Engines are usually replaced with a new unit rather than rebuilt. A transmission that’s worth rebuilding goes to a transmission builder in Phoenix. If it isn’t worth rebuilding, we install a replacement unit. We go with whichever costs you less.
Duramax diesels
The 6.6L and 3.0L Duramax have their own page, organized by engine generation: Duramax repair in Phoenix.
What should go to the dealer
Some GM work belongs at the dealer. Recall repairs and repairs covered by GM’s factory warranty cost you nothing there, and we’ll tell you when that’s the case. For maintenance and repairs you’re paying for either way, the FTC says a dealer can’t deny your warranty coverage because the work was done somewhere else. Keep your receipts.
Here, you hear the price before any work starts. Payment plans through American First Finance are on our financing page.
Booking a GM
Tell us the year, the model and the engine, and what it’s doing. If you have the VIN handy, send that too.
More GM work at Floorjack
- Duramax repair in Phoenix: every 6.6L generation and the 3.0L, by engine.
- Tire and wheel alignment: what an alignment does after steering or suspension work.
- Brake and chassis service: brakes, steering and suspension on trucks and SUVs.
- Check engine light in Phoenix: what a code means and how the fault gets found.