The right go kart rear differential or axle assembly depends on your frame, wheel hubs, chain, and powertrain. The 40-inch WPHMOTO axle kit is a useful candidate for buyers needing a longer axle, while the Yier 32-inch kit specifies a 25 mm shaft and 4-bolt hubs. The Yier housing is intended for a matching CV axle and drive shaft. For a build that needs reverse rather than a rear differential, the maXpeedingrods gearbox is a separate type of drivetrain component.
| Product | Best suited for | Key listed specification |
|---|---|---|
| maXpeedingrods Forward Reverse Gearbox | 30 Series setups needing reverse | 5/8-inch shaft; sprockets for listed chains |
| Yier Rear Drive Shaft Housing | DIY builds with matching CV components | 20 mm axle; 11:38 gear ratio |
| WPHMOTO 40-Inch Differential Axle | Builds needing a 40-inch axle | 16-tooth drive axle |
| Yier 32-Inch Differential Axle Kit | Builds using 25 mm axle and 4-bolt hubs | 110 mm hub bolt spacing |
| TJHSM 40-Inch Electric Rear Axle Kit | Electric builds considering a motor-and-axle kit | Options list 48V motors |
maXpeedingrods Forward Reverse Gearbox
This is a forward-and-reverse gearbox, not a rear differential. It is best for a go-kart builder using a 30 Series setup who needs reverse gear and a compatible gearbox rather than an axle differential. The listed engine limit is up to 14 HP, and the kit includes 10-tooth and 12-tooth sprockets for specified chain types.
Listed specifications include a 5/8-inch shaft with a 3/16-inch keyway, a gearbox speed of 5/13 of clutch speed, and forward and reverse ratios of 1:1.3 and 1:2.6. Mounting plates, shifter parts, and cables are included. Avoid choosing it as a replacement differential: its stated application is a 30 Series gearbox, and the chain and shaft requirements need to match.
Yier Rear Drive Shaft Housing
This rear drive shaft assembly is best for a DIY ATV, go-kart, quad, or buggy project whose other drivetrain parts match its dimensions. The listing gives a 20 mm axle diameter, M12 thread diameter, 6T spline, and 11:38 gear ratio. Those measurements make it easier to compare against an existing axle and related components before purchase.
The key limitation is explicit: it fits only the seller’s CV axle and drive shaft. Buyers should verify the mating components, spline, and thread details rather than assume it works with a standard go-kart axle. It is selected for builds that need a housing and gear-set assembly, not simply a bare axle.
WPHMOTO 40-Inch Differential Axle Kit
This kit is best for builders who need a 40-inch rear axle and want a listed 16-tooth drive axle. The product description says the axle is made from high-strength chrome and is designed to adjust wheel-speed differences for vehicle stability. It also states that it can support more than 500 pounds.
Check the axle length and the fit of the drive, hubs, and frame before selecting it. The supplied details do not specify shaft diameter or hub bolt pattern, so those dimensions should be confirmed for your build. This kit is a better starting point when 40 inches is the needed length than when a compact axle is required.
Yier 32-Inch Differential Axle Kit
This kit is best for a build that calls for a 32-inch axle, a 25 mm drive shaft, and 4-stud wheel hubs. Listed details include a 6T spline, 110 mm hub bolt spacing, and a disc rotor outer diameter of 190 mm. Those measurements provide useful checkpoints when replacing a rear assembly or planning a compatible vehicle build.
Choose this kit if its shaft, spline, hub pattern, and rotor dimensions match the parts already selected. The listing also describes it for electric vehicles and several small-vehicle types, but the supplied details do not specify every mounting measurement. Confirm frame and component fit before ordering.
TJHSM 40-Inch Electric Rear Axle Kit
This option is best for buyers comparing an electric motor and rear axle package for a go-kart, golf cart, or ATV-style build. The listing describes 48V motor configurations: a 500W option with a stated 3,000 rpm and a 1,000W option with a stated 4,800 rpm. It also lists different speed ranges for the two configurations.
The listing’s motor details do not provide the axle diameter, hub pattern, or other fitment dimensions in the supplied information. Verify which configuration is included and whether the axle fits your frame and wheels. Avoid choosing it based on motor speed alone if your main requirement is a specific differential ratio or axle interface.
Buying Guide: How To Choose A Go Kart Rear Differential
Do you need a differential, axle, or gearbox?
A differential or differential axle helps drive the rear wheels while accommodating different wheel speeds in a turn. An axle kit may include the axle and hubs, while a gearbox changes direction or gear ratio. The maXpeedingrods product is a forward-reverse gearbox, so it should not be treated as a rear differential replacement.
Which measurements should you check first?
- Axle length: Compare the listed 32-inch or 40-inch length with your frame and wheel spacing.
- Shaft diameter and spline: Match measurements such as 25 mm or 20 mm diameter and the specified 6T spline.
- Hub fit: Check bolt count and spacing, including the Yier kit’s 4-stud, 110 mm pattern.
- Drive interface: Confirm chain size, sprocket teeth, keyway, or CV axle requirements where applicable.
- Brake and frame clearance: Compare rotor and mounting dimensions with your existing parts; do not assume they fit from axle length alone.
How should you compare electric and engine-driven options?
Start with the powertrain already planned for the kart. A gearbox listing specifies engine and chain requirements, while an electric kit lists motor voltage and power. Check that the axle, drive components, and frame layout work together. The product details supplied here do not establish universal compatibility among these parts.
Frequently Asked Questions
Is a rear axle the same as a rear differential?
No. An axle supports and transfers drive to the wheels, while a differential allows the driven wheels to rotate at different speeds in a turn. Product listings may package these components together, so check the stated parts and specifications.
Can a forward-reverse gearbox replace a differential?
No. A forward-reverse gearbox changes drive direction; it is not the same component as a rear differential. The maXpeedingrods kit is specified for 30 Series use.
What does 6T spline mean?
It describes a six-tooth spline interface. Confirm that the mating component uses the same spline and fits the shaft dimensions before ordering.
Should I choose the 32-inch or 40-inch axle?
Choose based on the required axle length and the frame and wheel layout. Length alone does not confirm compatibility; also check shaft diameter, hubs, spline, and brake dimensions.
Does the Yier housing fit any CV axle?
No. Its listing says it fits only the seller’s CV axle and drive shaft. Verify those matching parts before buying.