Improve Jeep and 4×4 Performance with the TREMEC TR-4050 5-speed Manual Transmission


Improve Jeep and 4×4 Performance with the TREMEC TR-4050 5-speed Manual Transmission

The Jeep Wrangler is an iconic off-road vehicle. But through the years, the various models haven’t always had the best manual transmissions. For example, the Jeep YJ (1987-1995 model years) and Jeep TJ (1997-2006) lacked a decent First gear ratio, and owners found the transmissions to be less durable once larger tires and weight were added to the Jeep, including heavier axles and other off-road equipment. The factory NSG370 6-speed transmission found in the Jeep JK (2007-2018) was better, but there was still room for improvement in the eyes of Wrangler enthusiasts. The superior First gear ratio and incredible strength of the TREMEC TR-4050 5-speed manual transmission has made it a desirable upgrade not only for the Jeep Wrangler, but also many other light trucks and 4×4 SUVs.

The TREMEC TR-4050 5-speed has superior torque handling, shifting and off-road performance compared with most factory 4×4 manual transmissions. The high-contact constant mesh gears contribute to the 600 lb-ft torque capacity. Tapered roller bearings on the input, main and counter shafts increase internal stability and strength under heavy loads. And smooth shifting is made possible by single- and double-cone synchronizers with carbon friction material on all gears.

TREMEC TR-4050 5-speed Gear Ratios

The TREMEC TR-4050 5-speed was specifically built for light- and medium-duty trucks and 4x4s. With First through Fifth gears of 6.16, 3.11, 1.71, 1.00, .076 and a 6.03 Reverse gear, the TREMEC TR-4050 has a torque input rating of 600 lb-ft (more than twice the torque rating of factory transmissions found in 2018-and-earlier Jeep Wranglers).

Transmission1St Gear Ratio2nd Gear Ratio3rd Gear Ratio4th Gear Ratio5th Gear Ratio6th Gear RatioReverse Gear RatioTorque Rating
TREMEC TR-40506.16:13.11:11.71:11.00:10.76:1N/A6.03:1600 lb-ft
NSG3704.46:12.61:11.72:11.25:11.00:10.84:14.06:1260 lb-ft
NV35504.01:12.32:11.40:11.00:10.78:1N/A3.57:1300 lb-ft
Aisin AX153.83:12.33:11.44:11.00:10.79:1N/A4.22:1Up to 300 lb-ft depending on configuration

What Makes the TREMEC TR-4050 So Strong?

All forward gears in the TREMEC TR-4050 are fully synchronized using carbon friction material single- and double-cone synchronizers. For strength and increased internal stability, the input, main and counter shafts use tapered roller bearings. The TREMEC TR-4050 uses standard, readily available Dexron III/Mercon fluid for lubrication. A bonus is that the TREMEC TR-4050 also has a power take off (PTO) accessory port. The TREMEC transmission can be mated to a variety of original equipment and aftermarket transfer cases, including the Atlas from Advance Adapters.

The shorter case dimensions of the TREMEC TR-4050 allow for installation into most vehicles without modifications to the factory transmission tunnel. Multiple shifter locations make it possible to be swapped into a variety of older 4×4 vehicles. There’s also a built-in port for PTO accessories.

Swapping in a TREMEC TR-4050

In addition to its strength and smooth shifting, the TR-4050 has a more compact design than the NSG 370. This means there won’t be clearance issues inside the factory transmission tunnel. Multiple shifter locations also eliminates extensive modifications to the transmission tunnel when swapping the TREMEC TR-4050 into many older 4x4s. The shorter overall length of the TREMEC TR-4050 also makes it ideal for short-wheelbase 4x4s, such as the early Jeep CJ and first-generation Ford Bronco.