Sierra 1500
Half-ton Sierra, gas and the 3.0 Duramax — 8- and 10-speed shifts, brakes, A/C and the everyday work a light-duty truck asks for.
GMC Trucks & SUVs · Denton, TX · Since 1995
Professional Grade means you paid for something better — and keeping a Sierra, Yukon or Acadia that way takes a shop that knows GM inside out. Since 1995 we've serviced the Allison-and-Duramax HD trucks, the 8- and 10-speed automatics, the AT4 off-road hardware and the everyday brakes and A/C. One shop for the whole truck, Denali to work-spec.
Prefer to talk it through? Call (940) 514-8690
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Every System, One Shop
A Professional Grade truck deserves one shop that sees the whole picture. Every card links to that service's page; the transmission specialty leads the way.
The Allison behind a Duramax Sierra HD, the 8-speed (8L90) torque-converter shudder, 6L80 wear and the 10-speed — GMC drivetrains diagnosed and rebuilt in-house, backed by honored warranties and free 40-mile towing on major repair.
AFM/DFM lifter failure on 5.3 and 6.2 V8s, 3.6 V6 timing wear, water pumps — GM engine work diagnosed before parts, delete options where it makes sense.
A Yukon or Sierra that tows goes through brakes faster. Grinding, a soft pedal or a light on — inspected, measured, then fixed for how you use the truck.
Blowing warm in the Texas heat? Recharge by weight, leak detection and compressor work — Denali tri-zone and Yukon rear-zone systems included.
Towing a Duramax in July is a cooling test — and heat kills transmissions. Radiator, water pump, thermostat and coolant service keep the temps in range.
A light on your GMC is a symptom, not a diagnosis. We scan, test and trace it to the real cause — no parts cannon on a premium truck.
Quick, done-right oil changes with a free multi-point inspection — the honest habit that protects a Denali's drivetrain over the long haul.
GMC Models We Service
Work truck, Denali or family hauler — every GMC is welcome. Don't see yours? We service them all; just call with your model.
Half-ton Sierra, gas and the 3.0 Duramax — 8- and 10-speed shifts, brakes, A/C and the everyday work a light-duty truck asks for.
The Duramax-and-Allison HD — towing heat, transmission service, heavy brakes and cooling on trucks that earn their keep.
Full-size GMC SUVs, Denali included — V8 and 10-speed patterns, rear-zone A/C and heavy brake duty for family and trailer.
GMC's midsize crossover — transmission service, brakes, cooling and the check-engine lights that come with the miles.
The midsize truck — 8-speed shifts, cooling under tow load, and the brake and suspension wear off-pavement use brings.
Compact Terrain commuters and the Denali trim across the line — premium hardware serviced with the care it was built with.
Professional Grade
A Sierra HD's Duramax-and-Allison combination is one of the best tow rigs on the road — and the transmission and cooling that make it capable are exactly what heavy work stresses hardest. AT4 owners add off-road miles on top. Here's what keeps a Professional Grade GMC professional.
Real Google Reviews
4.3 · from 288 Google reviews
I had a great experience with Eagle Transmission. The staff was very friendly, professional, and honest throughout the entire process. They carefully diagnosed my car, explained the issue clearly, and never pressured me into unnecessary repairs. Their pricing was very reasonable compared to other shops, and the quality of the work was excellent. My car is driving much better now, and I truly appreciate their honesty, customer service, and attention to detail. I highly recommend Eagle Transmission to anyone looking for reliable repairs at a fair price. Thank you for the excellent service!
Nice people and easy to work with. Gave me updates every step of the way. Would come here again for any service they provide!
Lived close by and picked this place these guys were professional and friendly my kind of place! I would recommend them And it was FAST!
Where to Next
Know what your GMC needs? Jump straight there. Most owners want one of these three.
8-speed shudder, an Allison acting up, harsh shifts or a warning light — our transmission page covers GM and Allison units in depth, with free 40-mile towing on major repair.
Transmission RepairA V8 tick, a misfire, a timing rattle — GM engine work, AFM/DFM lifters included, diagnosed before parts.
Engine RepairChevy, Ford, Ram, Toyota, Honda and more — foreign or domestic, start from your make.
Vehicles We FixGood to Know
Yes — the Allison transmission behind the Duramax in a Sierra 2500/3500 HD is a real Eagle specialty, rebuilt in-house rather than shipped out, along with the cooling and drivetrain a work truck leans on. We handle the transmission and drivetrain side of diesel trucks; for engine-internal Duramax work we'll point you to the right people.
Mechanically they're close cousins — a Sierra and a Silverado share the same GM drivetrains, so the same 8-speed shudder and AFM/DFM V8 lifter patterns can show up. What GMC adds is the premium Denali and off-road AT4 hardware. We know both sides, and we treat a Denali like the investment it is.
A light-throttle shudder usually points to GM's 8-speed torque converter; a tick or misfire on a 5.3 or 6.2 V8 often traces to a collapsed AFM/DFM lifter. Two different fixes — so we diagnose which one you actually have, and put it in writing before any work.
Yes — full repair. Transmission and drivetrain is our specialty, but the same shop handles your GMC's brakes, A/C, engine, cooling, electrical, diagnostics and oil changes, Sierra to Terrain. One trusted shop for the whole truck.
Denton, TX · Since 1995
Call now or request a free quote — honest diagnosis, warranty-backed work, and one shop for every system on your truck. Serving Denton, Lewisville, Flower Mound and nearby.