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For Gas/Diesel & Extreme EV-Powered Race Trucks.
Fits Behind TH400/4L80-4x2 Transmissions or direct to most electric motors.


The rx TorqueBox® will take you across the finish line every time.

The Problem
Larger diameter tires on race trucks require higher numerical ring and pinion ratios — the higher the numerical ratio, the higher the gear tooth surface speed and greater the fatigue. Under tough race conditions, it isn’t unusual for the ring and pinion to fail due to this increased surface speed. This kind of failure can be extremely costly, and not just because you lost a race. Replacement is expensive.

RX gearbox

The Solution
The rx TorqueBox® is the solution. With it's sheer brute strength, it creates the perfect gearing combination to prevent high gear tooth surface speed and catastrophic failure — no matter what size tires you are running. Designed specifically for the pounding a vehicle can take in off-road racing, from Baja to Dakar and everything in between. This high endurance unit will see your truck across the finish line every time. This reduction gearbox is Torque Tough to the Extreme!

The Application
The rx TorqueBox® comes with a complete installation kit, including an HD mount plate, splined coupler, billet fixed yoke, mounting hardware, and a step by step installation guide/service manual.

Note: Units are shipped without lubrication, fill after installation...see manual enclosed with the product for details.

Torque Trends - RX TORQUEBOX

To order call:
623 755 8214


  • Weight (THE BRUTE) - 36 lbs / 16.36 kg

  • Length - under 10 inches / under 25 cm

  • Diameter - 8 inches . 20.3 cm

  • Torque rating (ENGINE TORQUE) - 1250 lbf / 16057.1 Nm

  • Fluid Requirements -

    • synthetic ATF (cooler required)

  • Housings - 6061 T-6 aluminum 

  • Input Shaft - through hardened 300M with rolled splines

  • Gear Set - 9310 material, cryo-hardened, shot peened, RIM polished straight cut gears

  • Output Shaft - through hardened 300M with rolled splines

  • Yokes - billet 1350 or 1480 available

  • Alternator Drive - yoke-mounted billet alt. pulley available

  • Whole Unit - fully rollerized & balanced

  • Test Run - before shipping

CALL 623 755 8214

1480 Yoke
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