Hot Racing Steel Helical Diff Ring/Pinion Overdrive 33T/12T for Traxxas TRX-4 TRXF9312


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UPC: 083745308969 SKU: TRXF9312 Categories: ,


Hot Racing steel helical spiral overdrive 33T/12T gear set for 1/10 Traxxas TRX-4


– Precision machined helical spiral cut gears offer inherently greater strength and smooth operation than the factory Straight cut bevel gears

– High carbon steel construction

– Less vibration, less noise, less wear then stock straight cut bevel gears

– 33T/12T provides 9% overdrive (vs stock 34T/11T) increases the wheel speed and is commonly used in the front end for digs

– Works on front or rear. Use cases are typically front and rear at the same time, or front only to increase front digs


– One (1) 33 tooth spiral cut ring gear

– One (1) 12 tooth spiral cut pinion gear


– Installation following kit manual

– Medium threadlock (blue threadlocking compound) if screws are threaded into metal

– Hot Racing SPL10G05 high temp grease recommended


– Replaces Traxxas 8287

Option – overdrive the front axle, and underdrive the rear axle.

Combinations One. TRXF9312 in the front and TRXF9411 in the rear.

Combinstion Two. TRXF9411 in the front and TRXF9510 in the rear.

Combinstion Three TRXF9312 in the front and TRXF9510 in the rear.

Straight Bevel Gear

Spiral Bevel Gear

Teeth of this type of gear are straight and are cut along the axis on a cone.

Here the teeth are spiral and are cut in the form of spiral curve on the pitch cone.

Two teeth of the mating gears comes in sudden contact. The contact is always a line of length equals to face width of teeth.

Teeth of two mating gears gradually comes in contact. Engagement starts with a point and gradually becomes a line.

Due to sudden contact, teeth are also subjected to impact or shock loading.

Here teeth are subjected to gradual loading.

Sudden contact also causes noise.

Its operation is quite.

Shock loading induces vibration and thus its operation is not smooth.

Due to gradual building up of load, it produces less vibration and thus the operation is smooth.

Designing and manufacturing of straight teeth bevel gear are easier and thus these are cheaper.

Complicated design and manufacturing leads to higher cost for this type of gear.

It exerts less thrust force on the bearings that hold the shafts.

It exerts more thrust force on bearings.

Additional information

Weight 2 oz
Part Color

Part Type

Fit Vehicle


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