GPM Racing 20CR Steel Spiral-Cut Front Differential Gear 13T/37T for Traxxas 1/10 Slash 4x4 Lcg (SLA1337FS)

Technical overview of the SLA1337FS front differential

The SLA1337FS is a precision aftermarket front differential gear set engineered for TRAXXAS platforms that accept the #5379X/#5379R ring and pinion. Machined with helical spiral teeth from 20Cr carbon steel and supplied with a hardened black finish, the matched 37-tooth ring and 13-tooth pinion are intended for installation inside the front gearbox to transmit motor torque through the drivetrain.

Helical tooth geometry reduces peak contact stress by distributing load across multiple teeth during engagement, producing smoother rotation and improved load sharing under acceleration. The gears are cut for the correct spiral direction and matched for reliable mesh straight from the package.

Confirm the factory front diff part number in the chassis service manual before ordering. Installation requires access to the front gearbox, accurate shim placement and standard gear mesh checks to ensure correct contact patterns and bearing preload.

Packing includes

• 37-tooth diff spiral cut ring gear – 1pcs
• 13-tooth spiral cut pinion gear – 1pcs

Original Name / Part No:

5379X,5379R

Compatible Models

• TRAXXAS 1/10 SLASH 4X4
• TRAXXAS-XO-01-64077-3
• TRAXXAS 1/10 4WD FORD GT 4-TEC 2.0 -83056-4
• TRAXXAS 1/10 RUSTLER 4X4 VXL-67076-4
• TRAXXAS 1/10 4WD HOSS 4X4 VXL 3S-90076-4
• TRAXXAS 1/8 Jato 4X4 VXL-4S-90386-4
• TRAXXAS 1/10 4TEC 2.0 AWD CHASSIS WITH BRUSHED POWER SYSTEM 83024-4
• TRAXXAS 1/10 4TEC 2.0 AWD CHASSIS WITH VELINEON BRUSHLESS SYSTEM 83076-4
• TRAXXAS 1/10 CORVETTE AWD ON-ROAD CAR 93054-4
• TRAXXAS 1/10 Factory Five '33 Hot Rod Coupe AWD ON-ROAD 93044-4
• TRAXXAS 1/10 Factory Five '35 Hot Rod Truck AWD ON-ROAD 93034-4
• TRAXXAS 1/10 RAPTOR PRO 4WD OFF-ROAD TRUCK 101076-4
• TRAXXAS 1/10 Fiesta ST Rally FORD FIESTA AWD RALLY CAR 74054-4
• TRAXXAS 1/10 Mustang GT AWD ON-ROAD CAR 83044-4
• TRAXXAS 1/10 Slash 4X4 Ultimate BRUSHLESS PRO 4WD SHORT COURSE RACE TRUCK 68077-4
• TRAXXAS 1/10 Slash 4X4 VXL 4WD BRUSHLESS SHORT-COURSE TRUCK 68086-4
• TRAXXAS 1/10 Stampede 4X4 VXL 4WD BRUSHLESS MONSTER TRUCK 67086-4
• TRAXXAS 1/10 Toyota GR Supra GT4 AWD ON-ROAD CAR 93064-4
• TRAXXAS 1/10 Rustler 4X4 STADIUM TRUCK 67064-1
• TRAXXAS 1/10 Rustler 4X4 STADIUM TRUCK 67064-61
• TRAXXAS 1/10 Slash 4X4 SHORT COURSE TRUCK 68054-1
• TRAXXAS 1/10 Slash 4X4 SHORT COURSE TRUCK 68054-61
• TRAXXAS 1/10 Stampede 4X4 4WD MONSTER TRUCK 67054-61
• TRAXXAS 1/10 BIGFOOT 4X4 BL-2S-67134-4
• TRAXXAS 1/10 Ford Fiesta ST BL-2S-74154-4
• TRAXXAS 1/10 Ford Fiesta ST Rally VXL-74276-4
• TRAXXAS 1/8 Jato 4X4 BL-2S-90154-4
• TRAXXAS 1/10 Revo 3.3-53097-3
• TRAXXAS 1/10 Rustler 4X4 BL-2S-67164-4
• TRAXXAS 1/10 Rustler 4X4 VXL-67376-4
• TRAXXAS 1/10 Rustler 4X4 VXL Ultimate-67097-4
• TRAXXAS 1/10 Slash 4X4 BL-2S-68154-4
• TRAXXAS 1/10 Slash 4X4 VXL-68386-4
• TRAXXAS 1/10 Slash 4X4 VXL Ultimate-68277-4
• TRAXXAS 1/10 Slayer Pro 4X4-59076-3
• TRAXXAS 1/10 Stampede 4X4 BL-2S-67154-4
• TRAXXAS 1/10 Stampede 4X4 VXL-90376-4
• TRAXXAS 1/10 T-Maxx 3.3-49077-3

As a matched ring and pinion set, the SLA1337FS is supplied for front gearbox installation on compatible TRAXXAS models; follow the chassis service manual for correct assembly, shim placement and gear mesh verification.

What tolerances should I check after installation?

Check backlash, axial play and bearing preload. Ensure the contact pattern sits centrally across the tooth face and adjust shims if contact is off centre.

Does the set include a heat treatment?

The gears are supplied with a hardened finish for improved wear resistance; follow normal break-in and inspection routines when first fitted.

Can I use these gears in a high-torque build?

20Cr carbon steel with proper heat treatment provides good durability, but final suitability depends on motor power, gearing and how well mesh and bearings are maintained under load.

How should I set initial gear mesh?

Start with a light mesh, mark contact with gear marking compound, then adjust shims until the contact patch is correct. Recheck under rotation and after a short run.

Any special maintenance tips?

Inspect tooth surfaces periodically for pitting or uneven wear, maintain correct lubrication inside the gearbox and replace bearings if play increases to preserve gear life. Write Product Review Please sign in your account before you can write any review. Sign In Close

Made to order: GPM Racing parts are shipped to us from GPM’s factory, so please allow around 14 days for dispatch.