TRANSMISSION / TRANSFER CASE — 2003–2007 DODGE RAM 5.9L CUMMINS

Meet the backbone of your build. CPP Diesel engineers and supplies a CPP-exclusive Extreme Duty manual lineup—NV4500, NV5600, and G56—built in-house for real Cummins torque. Pair our manuals with proven 48RE options, deep pans, coolers, and NP271/NP273 parts to tow harder, race smarter, and daily with confidence.

Automatic (48RE) — Towing & Performance

• 03–07 48RE Transmissions (Category)
• SunCoast 48RE Guardian — with Converter (’04.5–’07 4WD)
• BD / ATS 48RE Packages & Builds
• Mag-Hytec 727-DD Double-Deep Pan (48RE)
• BD 1060602 Metal Pressure Transducer Upgrade  •  BD 1060604 Adapter
• CPP Braided Transmission Line Bypass Kit (’94–’07)  •  Mopar 52028920AI Cooler Line (48RE)

Manual Clutches & Hydraulics

• South Bend Clutches (’03–’07 Category) — NV5600/G56 single & dual disc
• Valair Clutches (’03–’07 Category) — Street, towing & dual disc
• NV5600 Clutch Kits (category)

Transfer Case — NP271 / NP273

• NP271 / NP273 Parts (’03–’07 Category)
• Rebuild kits, chains, input shafts (23/29-spline), range forks & sliders, pumps, seals & gaskets.

Why Buy Drivetrain from CPP Diesel?

• CPP-exclusive Extreme Duty manuals: purpose-built NV4500/NV5600/G56 options for serious torque and towing.
• Complete 48RE coverage: proven SunCoast, BD, ATS builds plus pans, coolers, and electronics fixes.
• End-to-end parts: clutches, hydraulics, lines, and NP271/NP273 internals for one-stop service.

Tech Notes & Fitment

• Year splits: NV5600 through early ’05; G56 from ~’05.5–’07. 48RE automatics across ’03–’07.
• Cooling & ATF: Deep pans and cooler line upgrades help keep 48RE temps in check under load.
• Manual clutch break-in: Most SB/Valair kits require 500–1,000 gentle miles prior to hard pulls.

Frequently Asked Questions

What’s special about CPP’s Extreme Duty NV4500/NV5600/G56?

They’re CPP-exclusive manual builds with upgraded internals and assembly practices to handle Cummins torque with smoother shifts and higher durability. See our manuals hub for specs and availability by year.

Should I choose NV5600 or G56 for my 03–07?

’03–’05 trucks typically use NV5600; ’05.5–’07 use G56. If you’re swapping, NV5600 is a cast-iron tank with close ratios; G56 is lighter with great shift feel. We can match gearing, clutch, and hydraulics to your power and use case.

Best reliability upgrades for a 48RE tow rig?

Start with a quality build (SunCoast/BD), add a deep pan, metal pressure transducer upgrade, and braided line/bypass kit to control heat and line pressure.

Which transfer case parts do I need for a rebuild?

Match NP271 vs NP273, then choose a rebuild kit (bearings/seals), chain, input/output shafts, and any worn forks. Our 271/273 section groups everything by platform.