Key Features
- 600 lb-ft torque capacity - strongest 4WD transmission available on the aftermarket
- Granny low 6.16:1 first gear for crawling, climbing, and obstacle navigation
- 0.76:1 overdrive fifth gear reduces highway RPM for better fuel economy
- 10-spline input shaft (1.125" diameter) with NV4500 bolt pattern for direct replacement
- 23-spline output shaft with 6-bolt transfer case mounting pattern - compatible with NP231, NP241, and similar Jeep transfer cases
- Die-cast aluminum alloy housing - 164 lbs total weight, 31 lbs lighter than cast-iron NV4500
- Standard right-side 6-bolt PTO provision for hydraulic pumps
- High-contact constant-mesh helical gears with tapered bearings on all shafts
- All forward gears and reverse fully synchronized with carbon friction material
- 109mm center distance for maximum gear strength
- Overall length: 27.80", shifter location 9.45" from transmission face
- 100% brand-new OEM-quality materials with 12-month/12,000-mile TREMEC warranty
- MDL extends warranty by one extra year from date of install plus a 1-year grace period
Description
The NV4500 has been out of production since 2007, leaving 4WD truck and off-road builders scrambling for used units with dwindling parts availability. The TREMEC TR4050 solves that problem - a brand-new, currently-in-production 5-speed with 600 lb-ft torque capacity that uses the same NV4500 bolt pattern for direct replacement in your classic K-Series, Blazer, Jimmy, Suburban, Ford F-Series, or Bronco build.
The gear ratio spread makes this transmission ideal for 4WD applications. The 6.16:1 granny low first gear delivers massive torque multiplication for crawling technical terrain, pulling through mud, or moving heavy loads from a dead stop - the kind of low gearing that 2WD performance transmissions like the TKO and Magnum simply cannot provide. Fifth gear's 0.76:1 overdrive brings highway RPMs down for comfortable cruising and improved fuel economy. Ratios are 6.16, 3.11, 1.71, 1.00, 0.76 with a 6.03 reverse.
Engineering choices prioritize durability and refinement. The die-cast aluminum alloy housing saves 31 lbs over the cast-iron NV4500 while maintaining rigidity under load. A massive 109mm center distance gives the helical gears plenty of tooth contact area for strength. Tapered roller bearings on the input, main, and counter shafts provide superior internal stability compared to needle bearings alone, while the counter-shaft-mounted 5th gear synchronizer reduces noise, vibration, and harshness in overdrive. All forward gears plus reverse are fully synchronized with carbon friction material for smooth, low-effort shifts - a major improvement over older truck transmissions.
The 23-spline output shaft uses a 6-bolt transfer case mounting pattern compatible with late-model Jeep transfer cases including NP231, NP241, and similar units. The standard right-side 6-bolt PTO provision allows running hydraulic pumps for winches, plows, or other auxiliary equipment. Oil capacity is 3.5 liters (3.7 quarts) using TREMEC-approved T-M99 Synthetic ATF. Quick Draw Brand bellhousing adapters are available for Chevy small-block, LS, big-block, and Duramax; Ford Windsor and Modular; Mopar small-block and Gen III Hemi; Cummins 4BT, 6BT, 5.0L, and R2.8; plus Isuzu, IH Scout, and Detroit diesel applications. The TR4050 is an ideal replacement for AX15, NV3500, NV3550, and NV4500 5-speeds as well as NP435, T18, T19, T98, SM420, and SM465 4-speeds.
Kit Includes
- TREMEC TR4050 5-speed 4WD transmission assembly
- Die-cast aluminum alloy housing (end-loading design)
- 10-spline input shaft, 1.125" diameter
- 23-spline output shaft with 6-bolt transfer case mounting flange
- Right-side 6-bolt PTO cover
- Internal multi-rail shifter mechanism
- Reverse light switch
- Fill and drain plugs
- 12-month/12,000-mile TREMEC factory warranty
- MDL extended warranty: extra year from date of install plus 1-year grace period
- Lifetime technical support when purchased as part of complete MDL conversion package