YijiaLink 48P Pinion Gear Set 5-Pack (14T-18T) Steel, 3.175mm Shaft for 1/10 RC Cars

This 5-pack of steel 48-pitch pinion gears from YijiaLink includes five common tooth counts—14T, 15T, 16T, 17T, and 18T—each with a 3.175mm (1/8-inch) bore designed for 1/10 scale RC cars and trucks using a standard 3.175mm motor shaft. Each gear comes with its own grub screw and a small wrench is included for installation. They are made from hardened steel for long-term durability and reuse across multiple builds or replacements.

Which cars are these gears meant for?

The 3.175mm bore fits the vast majority of 1/10 scale brushless and brushed motors available. Brands such as Arrma, HPI, Kyosho, Losi, Axial, Traxxas, Tamiya, and Associated are listed as compatible, but any 1/10 RC car or truck that uses a 3.175mm motor shaft and a 48P spur gear should work.

How do I make sure these pinion gears fit my RC motor?

Two checks are critical. First, measure the motor shaft diameter—it must be exactly 3.175mm. Second, check that your spur gear is also 48 pitch (48P). If the pitches don't match, the teeth will not mesh properly. This set is not compatible with 32P, 64P, or other pitch sizes.

Choosing the right tooth count and avoiding overheating

Changing the pinion gear changes the gear ratio, which directly affects motor and ESC load. A larger pinion (e.g., 18T) raises top speed but increases heat. A smaller pinion (e.g., 14T) improves acceleration but lowers top speed. After installing a new pinion, check the ESC and motor temperatures regularly during the first run to avoid overheating.

Frequently asked questions

Does the set include a tool for tightening the screws?
Yes, a small wrench is included in the package.

Are these gears made of steel or aluminum?
They are made of steel, which offers good durability and can be reused multiple times.

Can I use these on a 1/8 scale RC car?
The set is specified for 1/10 scale. 1/8 scale cars typically use larger shafts (5mm) and different pitch gears, so these will not fit.