Simmons Diesel Performance, LLC

I purchased a 2023 GMC 2500 HD last year. I had dealings with the local GM dealer an they could not deliver the level of honesty I needed out of a dealer. Simmons Diesel was recommended as an alternative to taking it to a local dealer. After each service, they addressed my concerns, made educated recommendations. His pricing is right and though I have not had any major repairs, I will certainly value his opinion and will continue to use Simmons as my "Go-To for my maintenance on my GMC!

There was an amazing experience at Simmons Diesel. They didn't just fix the problem with the truck; they went the extra mile and found massive amounts of missing hardware on the front end, removed cross-threaded bolts, and even fixed all the wiring. Their machine shop in the back is seriously impressive – it could easily compete with bigger shops in the state. The meticulous care and attention to detail shown made me feel really comfortable spending a large amount of money there. Simmons Diesel is highly recommended, and I will definitely be taking the truck back to them for everything, no matter how big or small.

I had a cp4 disaster kit and crack case bypass along with a full service and vacuum pump gasket. Priced was fair service was excellent 👍 I'll always return here. 2015 F250

Turbo actuator went out on my truck, called to schedule and dropped it off same day. It was ready the next day. 5 star all around, great people!

This place of business is one of the most professional and knowledgeable shops. I have come across The owner had to install 4 different Allison, 1000 transmissions. In my duramax. This man has worked with me. And took very good care of me. While He was trying to take care of other customers. This man went through a lot to get my truck up and running due to faulty transmissions. And for the customers who've been waiting on their vehicles, I apologize to y'all. Because i'm the reason why he fell behind if you're looking for an honest shop to not rip you off and tell you what it is and work with you. This is the shop for you. He has been dealing with my truck for almost 6 months or 5I should say, and he stuck with it every step. Dealing with warranty claims corporate Policies and everything h