Traxxas TRX-4 Ford Bronco

Stock is as the vehicle ships. Calculated is worked from the stock figures on this page rather than stored beside them, so the two cannot drift apart. Not published means it exists but no source we could find prints it.

How does this gearing compare with similar cars? What's a normal final drive for your RC?

Gearing parts

Tooth counts are the ones in the specifications above. Pitch is given as metric module (Mod 1, Mod 0.8) or diametral pitch (32P, 48P). They are different standards and are not interchangeable, even where the numbers look close. Bore is the pinion’s hole, listed separately from the motor shaft (3 mm on the stock motor). Linked part numbers go to the maker's or official distributor's page for that part.

Buying a new pinion or spur? Check what’s fitted first: Why your RC's gear specs might not add up

How these numbers were settled

Two-speed, shifted from the transmitter.

• The owner's manual says the truck is 'equipped from the factory with a 45-tooth spur gear and 11-tooth pinion' and prints two formulas: spur divided by pinion times 6.32 in high gear, and times 15.8 in low.
• That gives 25.85:1 in high, used here as the final drive, and 64.64:1 in low.
• The parts list names the 11-tooth pinion (6747) and 45-tooth spur (8053) in regular type, the mark Traxxas uses for stock parts, and both part pages list the Bronco as a stock fitment.
• The stock tires are 1.9 in Canyon Trail, which Traxxas's TRX-4 comparison chart sizes at 4.64 in (117.9 mm) tall.
• The Titan 21T motor is brushed, so it has no KV rating.
• Portal axles.
• Traxxas publishes no portal reduction for the 1/10 TRX-4; 2.5559 is worked back from its printed high and low figures.
• Mechanically the Bronco matches the TRX-4 Land Rover Defender, with a different body and a lighter weight.

Documents

• ManualOwner's manual, model 92076-4 (Traxxas PDF) (opens in a new tab)Gearing p. 27
• Gearing chartGearing charts, high and low (in the owner's manual) (opens in a new tab)p. 27
• Parts listParts list, 92076-4 (Traxxas PDF) (opens in a new tab)Pinion and spur gears, p. 5

Sources

• trx-4-ford-bronco-92076-4traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• 6747-11-tooth-pinion-gear-3…traxxas.com (opens in a new tab)
• 8053-45-tooth-spur-gear-32-…traxxas.com (opens in a new tab)

Every figure on this page traces to one of these. Where they disagreed, the note above says which was used and why.

More from Traxxas

• Summit 4WD
• T-Maxx 3.3
• TRX-4 Chevrolet K10 High Trail Edition
• TRX-4 Defender
• TRX-4 Sport
• TRX-4 Sport High Trail Edition
• TRX-4M Chevrolet K10 High Trail Edition
• TRX-4M Defender