performance diesel
Transmissions
strong & reliable

Maximum Durability
Dodge/RAM & Chevy/GMC
Solving transmission issues
We solve the problems that cause diesel truck transmissions to fail. Whether you’re dealing with slipping, overheating, or a unit that can’t handle towing or horsepower, we build proven solutions for Cummins and Duramax trucks. We specialize in 68RFE, 48RE, 47RE, and Allison 1000 transmissions, and we build them to eliminate weak points and handle real-world stress with reliable, consistent performance.
builds
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Performance Diesel Transmissions Built to Handle Real Power
At RedLine Transmissions, we eat, sleep, breathe, and live diesel performance. Our custom performance diesel transmissions are built and durability-tested for real-world use — heavy towing, high horsepower, daily driving, or weekend fun — we’ve got the perfect build for your truck. We engineer and build every transmission for reliability, precision, and maximum performance using high-quality components, expert assembly, and real-world testing.
If you want a transmission that shifts crisp, handles your truck’s full power, and makes driving fun and effortless, RedLine has you covered.
RedLine Transmissions engineers, assembles, and tests every 68RFE, 48RE, 47RE, 47RH, and Allison 1000 unit in-house to put your power to the ground and keep your truck moving strong.
RedLine Builds It Better. Built for how you actually use your truck.
Diesel Performance Parts & Upgrades
We understand that diesel enthusiasts have diverse needs, from daily driving and heavy towing to exhilarating drag racing and competitive truck pulling. That’s why we offer an extensive range of products, including cold air intakes, turbochargers, twin turbo kits, and 48-state legal tuners, carefully selected from the industry’s best brands.
RAM 2500/3500 Transmission Parts
From Valvebodies to Billet Heavy Duty Output Shafts, Front Pumps, Billet Flex Plates, and Torque Converters, our products are the result of rigorous testing and real-world experience. We don’t just sell these parts; we use them in our own transmission builds to ensure they stand up to the toughest challenges. When it comes to transmission parts, we’re committed to doing whatever it takes to keep your Dodge Ram Cummins Transmission running smoothly and reliably.
Experience-Built Automatic Transmissions
With nearly 25 years in the industry, we KNOW Cummins and Duramax transmissions. We build performance transmissions for Dodge RAM 68RFE, 48RE, and 47RE, as well as Chevy Allison 1000/2000. Our diesel transmissions are custom-built in-house with QUALITY USA parts, designed for longevity, with the added benefits of power and performance.
We know the truck. we build the transmission.
Years of hands-on experience with diesel trucks drive every transmission we develop. We understand how these trucks work, where they fall short, and what it takes to build a transmission that performs.
Work
Your truck earns its keep. Whether it's pulling equipment, hauling a load, or putting in long days, you need a transmission that works as hard as you do.
Tow
Hook up. Load heavy. Keep moving.
You didn't buy a diesel to leave it sitting. From the camper to the equipment trailer, you expect your truck to pull with confidence and handle the miles ahead.
Perform
More power. More capability. No compromises.
You know what your truck can do, and you're always looking for more. You want a build that puts power to the ground and keeps up with the way you drive.
Tech Talk
Helpful information, advise and knowledge for the experts about automatic diesel transmissions and performance upgrades. If is has horsepower or you want to add more horsepower, this is the place for you.


2018 RAM 2500
68RFE Transmission - "The 550"
Solid Transmission Build!
"Have had a RedLine Transmission in my truck for 1,200 miles. Transmission is very solid and you can feel the transmission holding on to the gears longer while in use. Another big plus is that they had my truck in and out in five days. This is great because my truck is a daily driver and tow rig. 100% recommend this company. Can't wait to tow the fifth wheel this summer.
- Tim B.

2002 Dodge Ram 2000
47RE Transmission - "The 650"
Built & Shipped!
I purchased a built 47RE Transmission for my Ram pickup and it has been driving beautifully so far. Amazing customer service, great product and a pleasure to work with. Definitely recommend!
- Deagan O.

2016 Ram 2500
68RFE Transmission - "The 700"
Highly Recommended
"Had by 2016 68RFE rebuilt at RedLine. Nothing but good things to say. They are priced right. It's been 8 months and 10,000 miles and it is running super strong with no issues. Highly recommended!
- Aris A.

2020 RAM 2500
68RFE Transmission - "The 550"
Nothing but the best!
Quality of the work and the service you receive. Worth it to check them out and get your work done.
- Steve Z.












