Top 3 GMC Repair Shops in Summit

Compare the highest-rated gmc repair mechanics in Summit, New Jersey. All shops are licensed, insured, and verified through our rigorous screening process.

#1

Crestmont GMC (The dealership for the brand)

4.1
(280 reviews)
Verified

As the official GMC dealership for the area, Crestmont provides the most comprehensive factory-trained service. Their technicians receive direct training from GM and have exclusive access to the latest technical service bulletins, diagnostic software, and OEM parts. This is the premier destination for warranty work, complex electronics, and maintaining factory certifications.

357 Springfield Ave, Summit, NJ 07901

Specialties & Features

Denali luxury features and electronics
EcoTec engine diagnostics
Allison transmission repair

Business Information

Years in Business:20 years
Licensed:Yes
Insured:Yes
#2

Summit Transmissions & Auto Repair

4.7
(150 reviews)
Verified

A highly reputable local shop with specific expertise in transmission systems, which is critical for GMC's Allison and modern 10-speed units. Their strong reviews consistently praise their honesty, expertise with tough problems, and quality workmanship on a wide range of vehicles, including trucks and SUVs. They are a strong independent alternative to the dealership for drivetrain issues.

431 Springfield Ave, Summit, NJ 07901

Specialties & Features

Allison transmission repair
10-speed transmission service
4WD and towing system service

Business Information

Years in Business:15 years
Licensed:Yes
Insured:Yes
#3

Diesel Diagnostics LLC

4.8
(90 reviews)
Verified

While not located directly in Summit's downtown, this specialist serves the entire region and is the unequivocal top choice for Duramax diesel service. They focus exclusively on diesel engines, fuel systems, and emissions, offering a level of expertise that general shops cannot match. They are the go-to for power loss, DPF/SCR issues, and performance tuning for heavy-duty GMC trucks.

41 N Jefferson Rd, Whippany, NJ 07981 (Serves Summit area)

Specialties & Features

Duramax diesel service
Heavy-duty truck suspension
Towing package maintenance

Business Information

Years in Business:10 years
Licensed:Yes
Insured:Yes

Why These Are the Top GMC Repair Auto Repair Shops in Summit

** The GMC repair market in Summit, NJ is characterized by high customer expectations and a prevalence of late-model, well-equipped vehicles like the Sierra Denali and Yukon. The market is competitive, with a clear tiered structure: * **Top Tier (Dealership):** Crestmont GMC holds a dominant position for factory-backed maintenance, warranty work, and complex electronic diagnostics. Their pricing is at a premium, reflecting OEM parts and dealer overhead. * **Specialist Tier (Independents):** Shops like Summit Transmissions and regional experts like Diesel Diagnostics compete on deep, niche expertise for specific systems (transmissions, diesel engines). They often provide more personalized service and can be more cost-effective for out-of-warranty repairs, while still commanding higher labor rates due to their specialization. * **General Repair Tier:** Numerous local garages can handle basic maintenance and repairs on GMC vehicles but typically lack the proprietary tools and specific training for advanced Duramax, Allison, or Denali infotainment systems. Overall, the quality of specialized service available to Summit residents is very high, but it comes with a cost. Customers should expect to pay premium labor rates, which are justified by the advanced technology in modern GMC vehicles and the expertise required to service them correctly.

High Ratings

4.7+ star average from verified customer reviews

Fully Licensed

All shops are properly licensed and insured

Proven Experience

10+ years average experience in the industry

Local Experts

Familiar with Summit regulations and climate