Fast & Great service would recomend to everyone that need services on the truck. Even does annuel…read moreinspections.

I took my Cummins Diesel Motorhome to a high end truck shop, they spent the whole day with it and…read morecouldn't figure out the issue, I called Juan and he came to my house, diagnosed and fixed my motorhome, he changed the lift pump and fuel filter and had me back on the road! Juan, Andres and Jerry are good hardworking men, I will definitely call them back if I need help in the future.

Came in for a coolant leak and check engine light. Mechanics were able to get repair the leak and…read morelet me know what the check engine like was for. I was back up and running in under 2 hours.

Martin and his crew did a great job! We emailed late when we found a leaking axle seal......They…read moreresponded immediately and had it fixed the very next day for a fair price. VERY happy. Would definitely recommend and will use them again!

Had a good experience at Mad Tech the other day. My diesel truck kept running the battery down if I…read morelet it sit for too long so I found a diesel shop that was able to find the problem. I can't tell you if the price was fair or not but the problem was fixed.

I purchased a used 2014 Ram 3500 and needed to get it inspected for any outstanding issues. I have…read morenever owned a diesel before so I googled what coud go wrong with the 6.7 Cummins engine and brought the list in with the truck. Trenton went over every item in the list giving me a ballpark estimate of the possible future repairs. Left the truck for inspection and there were a number of items that needed to be repaired. Trenton gave me a wealth of information of what to look out for and how to drive the truck for maximun longevity. Mad Tech Diesel Workz is where I will be taking my truck for future service.

As a business owner trying to find a central location to have my loaded trailers stored safetly is…read morediffcult to find. Luckily Rafael Was able to answer any doubts and questions i had. Great Pricing I will be working with R&R fleet moving foward! Thank You R&R

From the owner: Located in the center of Fontana. We provide Secure Truck & Trailer Parking - We offer Truck,…read moreTrailer & Tire Repair

Get business Had my truck ready in 2 days. They did a great…read morejob. They replaced an injector and a few sensors that we're setting off the check engine light and causing the engine to go into protection mode.

Good work reasonable with the prices good customer service they fixed my truck runs like newread more

Superb service and support! FTR really got me out of a difficult situation with my vehicle which…read moreneeded a full engine replacement! The team went the extra mile to help me get it to the shop. They were helpfully informative with their diagnosis and repair plan. They took care of finding good quality parts while ensuring that the job was completed in a timely manner. I was back on the road before I knew it! For context, I went with this after receiving a ridiculously high quote from a different shop. This place offered me a reasonable price while giving me a piece of mind.

Great honest and reliable service. They have serviced our diesel motorhome and truck several times…read moreover the years. They also do house calls. I recommend their service.

Robert and Alexis were great. This was my first visit bringing in my 2007 Dodge Ram 3500. They were…read morevery accommodating when I ask to drop the truck off and pick it up the next day. I will say, they aren't the cheapest, but finding a good diesel repair shop in socal is tough to do. Thanks guys! I'll be back soon.

Stay away from this place. I only brought my work truck here because my regular mechanic was sick…read moreand I needed to get back on the road. Big mistake. I told them right from the start I was pretty sure it was the alternator. Their "expert" argued with me, insisted it was the computer (PCM), and tried to quote me $4,800. I didn't trust it, so I took my truck back. Sure enough, once my regular mechanic looked at it, it was just the alternator. The worst part happened later. The owner, Robert, texted me admitting his tech messed up ("technician misdiagnosed the vehicle") and refunded my diagnostic fee. That was fair. But then he tried to offer me a free oil change if I would "show forgiveness" (delete my bad review). I said no way. A free oil change doesn't make up for the 3 days of work I missed (that's over $2,000 in lost income) because my truck was sitting there for nothing. If I didn't know about trucks, they would've taken $4,800 from me for a part I didn't even need. Don't risk it.

These guys are a bunch of haks with absolutely zero mechanical integrity or accountability for…read moreservices not rendered properly. I experienced what I assumed was transmission problems while driving through Fontana, CA. in Nov 2025. I was driving a 1999 Fleetwood Pace Arrow with the Ford V10 F-53 chasis. Good Sam towed me to J&L where it was discovered that my flywheel had broken. They jacked up the front end & backed the transmission off so they could get to the flywheel. in doing so they broke a cooling line and spliced it instead of replacing it. They installed the wrong flywheel then left a main transmission wiring harness unsecured which allowed it to fall onto my header and short out three solenoids in my transmission causing catastrophic failure. Additionally, the compression fitting that was used to splice the cooling line leaked so they shoved an O ring in it which eventually clogged the line causing further damage

From the owner: J & L Truck Repair LLC has proudly served Fontana and the Inland Empire since 2015, specializing in…read moreprofessional diesel semi-truck repair and maintenance. We know how important it is to keep your trucks on the road, so our team provides fast, reliable, and affordable service for both independent drivers and fleet operators. Our services include complete diagnostics, engine repair, brakes, transmissions, suspension, preventative maintenance, and more. Whether it’s a minor fix or a major repair, we get the job done right the first time. We take pride in honest service, competitive pricing, and quality workmanship that truck drivers can count on. Walk-ins are welcome, and we work hard to minimize downtime so you can get back on the road quickly. At J & L Truck Repair LLC, your rig is in good hands.