INJORA 9.7:1 Overdrive Transmission Gear Set – Stainless Steel – Fits TRX4M 1/18 RC Crawlers
INJORA 9.7:1 Overdrive Transmission Gear Set – Stainless Steel – Fits TRX4M 1/18 RC Crawlers
This INJORA gear set is a stainless steel transmission upgrade for 1/18 RC crawlers like the TRX4M Defender, Bronco, K10 High Trail, and F150. It features a 9.7:1 overdrive ratio that increases wheel speed by approximately 71% while maintaining durability with CNC-machined construction.
What makes the 9.7:1 overdrive gear set different?
Overdrive gears route more power to the axles, which effectively lifts the front of the vehicle and improves ground clearance during climbs. The 9.7:1 ratio delivers about a 71% speed increase at the wheels, helping the crawler push over obstacles more aggressively.
Technical details at a glance
| Material | Stainless steel |
| Weight | 15 g |
| Ratio | 9.7:1 overdrive |
| Speed increase | Approximately 71% |
| Included | All transmission gears and an 11-tooth motor pinion |
| Compatibility | TRX4M Defender, Bronco, K10 High Trail, F150 |
What comes in the box and what vehicles does it fit?
The set includes all transmission gears needed for the upgrade plus a separate 11-tooth motor pinion. It's designed as a direct replacement for the stock gear set in 1/18 scale TRX4M models—specifically the Defender, Bronco, K10 High Trail, and F150. No additional parts are required beyond the included components.
Why stainless steel matters for RC crawling
Stainless steel offers excellent resistance to rust and corrosion, which is a real advantage when running in wet or muddy conditions. The CNC machining process ensures precise tooth profiles and a smooth surface finish, which helps reduce wear over time. Combined, these qualities contribute to a longer service life compared to standard plastic or less durable metal gears.
Frequently asked questions about this upgrade
Do I need to grease the gears before installation?
Yes, the manufacturer recommends greasing the gears to ensure smooth operation and to protect the metal surfaces during use.
Will this fit my stock TRX4M without modification?
It is designed as a direct replacement for the listed TRX4M models. No modifications should be needed for those specific vehicles.
How much does the set weigh?
The complete gear set weighs 15 grams.
What is the tooth count on the pinion?
The set includes an 11-tooth motor pinion.