If you use your diesel truck for what it was actually built for, you know, like towing heavy loads, your daily work truck, or long haul transport, you know that the "factory" OEM setup doesn't always hit the mark. Ultimately, between the weight of the trailer and the heat of the road… it'll take a toll on your drivetrain.

The Ready Run Heavy Hauler collection is designed to solve that exact problem. It’s a designated lineup of "drop in" performance upgrades built specifically for the challenges of heavy duty Cummins diesel engines.

What is the "Ready Run" Concept?

The "Ready Run" philosophy is simple: Less time in the shop, more time on the road. Unlike custom builds that require weeks of waiting or complex installation of individual parts, these are complete, dyno tested units (transmissions, long blocks, and components) that arrive ready to install. They are designed to replace your stock engine (and all that goes with it) with something significantly more robust that you can truly depend on. 

Key Highlights of the Heavy Hauler Series

1. Transmissions

The heart of the collection is the Heavy Hauler transmission. These units are upgraded to handle the "death by a thousand tows" that kills basic stock transmissions.

• Increased Holding Power: Features up to 25% more clutch material and reprogrammed valve bodies for higher line pressure.

• Heat Management: Every unit comes with a heavy duty, deep sump aluminum pan for extra fluid capacity and better cooling.

• Reduced Friction: Stock thrust washers are replaced with high strength roller Torrington bearings to prevent internal metal shavings and heat buildup.

2. The Heavy Hauler Long Block

For those looking for a complete engine refresh, the Heavy Hauler Long Blocks (available for Cummins  5.9L &  6.7L) are built for endurance.

• Improved Airflow: Many models feature CNC ported heads for better breathing.

• Lower EGTs: Equipped with street/towing performance camshafts designed to lower Exhaust Gas Temperatures (EGTs) by 200–300 degrees. Yes, EGTs do matter!

• Maximum Strength: Using ARP head studs and reinforced internals, these engines are rated for up to 700+ HP while remaining reliable for daily work.

3. Peace of Mind Warranty

D&J Precision Machine doesn't just build these for power; they build them for longevity. Most Heavy Hauler packages come with a competitive 3-year or 150,000-mile warranty, covering parts and labor. Let's be honest, that's a rarity in the performance aftermarket world.

Is a Heavy Hauler Right For You?

If you find yourself watching your transmission temperatures climb every time you hit a grade, or if your stock engine is struggling to keep up with your payload, the Heavy Hauler series is your answer.

By addressing the known failure points of factory components (like the weak overdrive clutches in the 68RFE or the heat issues in the Allison 1000), this will ensure that your truck stays on the road, not a project.