Best 90 Degree Gearbox For Go Kart: Compare 10 Options

#1 · Best Overall

1. Holdia 40 HP Two-Shaft Gearbox

• Weight: 22.5 lb
• Package Dimensions: 10.1 x 10.1 x 5 in

Best for: Two-shaft 40 HP replacements.

Why it ranks #1: Its 1:1 CW/CW drive, two 1-inch keyed shafts, 1,800-rpm maximum input speed, and stated 40 HP rating are clearly specified.

A stated 40 HP input rating paired with two keyed 1-inch shafts makes this Holdia gearbox a defined option for a substantial right-angle drive. Its CW-to-CW 1:1 operation preserves rotational direction and ratio, while the specified 1,800 RPM maximum helps frame operating requirements.

Both shafts measure 1 inch by 2-1/4 inches and use 1/4-inch keyways, giving buyers matching keyed connection dimensions at the input and output. The 4-1/4-inch square pattern with 3/8-inch tapped holes sets the mounting interface, and the 5-7/8 x 6-1/4 x 4-1/8-inch body dimensions help with layout planning. Together, the rating, direction, shaft details, and mounting pattern support a more specific compatibility check before installation.

Skip it if you need stated lubricant type and fill quantity before setup; the supplied Holdia details do not specify them.

This Holdia suits buyers seeking a 40 HP-rated, two-shaft 1:1 gearbox with a defined mounting pattern and keyed connections. Match its dimensions and rotation to the kart layout, and resolve lubrication needs before operation.

Listed on Amazon as: 40 HP Right Angle Bevel Gearbox 19455-SR-KW-KW-GR with 2 Keyed Shafts 1:1

#2 · Cast-Iron Housing

2. Lamerto 40 HP Two-Shaft Gearbox

• Weight: 23.9 lb
• Package Dimensions: 10.5 x 10 x 6.5 in

Best for: High-capacity keyed-shaft setups.

Why it ranks #2: The 1:1 gearbox has two 1-inch keyed shafts and a 40 HP rating; its cast-iron housing is described as sealed and it ships without oil.

A stated 40 HP input rating and two 1-inch keyed shafts distinguish this Lamerto right-angle gearbox for higher-capacity drive layouts. Its 1:1 ratio transfers speed without a ratio change, while clockwise input produces clockwise output, helping buyers assess direction and shaft connections before planning an installation.

The 4-1/4-inch square bolt pattern with 3/8-inch tapped holes gives a defined mounting footprint, and matching 1-inch shafts with 1/4-inch keyways provide keyed connections at input and output. A cast-iron housing is sealed to protect the gears and taper roller bearings. The gearbox is rated for a maximum 1,800 RPM and 40 HP; it ships without oil, so the stated 1/3 quart of 80-90W oil must be accounted for during setup.

Skip it if you need a gearbox supplied ready-filled; this one ships without oil and calls for 1/3 quart of 80-90W lubricant.

Choose this Lamerto when a project needs a 40 HP-rated, 1:1 right-angle drive with two keyed shafts and clockwise output. Check the mounting footprint, shaft dimensions, direction, and oil requirement against the intended kart installation.

Listed on Amazon as: 40 HP Right Angle Bevel Gearbox with 2 Keyed Shafts CW/CW 1:1, Cast Iron housing, Part No.#19455-SR-KW-KW-GR Lamerto

#3 · Crosshole Shaft

3. Generic Crosshole Gearbox

• Weight: 23.6 lb
• Package Dimensions: 10.5 x 10 x 6.5 in

Best for: Crosshole shaft installations.

Why it ranks #3: This 1:1, 40 HP unit lists 1-inch keyed shafts, a 1,800-rpm maximum, and a crosshole shaft feature for buyers needing that shaft detail.

A crosshole shaft paired with a 1-inch keyed shaft gives this right-angle gearbox a distinctive connection option for layouts requiring those shaft features. It is listed for CW-to-CW 1:1 operation, with a 40 HP rating and a maximum input speed of 1,800 RPM.

The 4-1/4-inch square bolt pattern with 3/8-inch tapped holes establishes a specific mounting interface, while the 5-7/8 x 6-1/4 x 4-1/8-inch dimensions help assess available space. Its 1-inch shafts have 1/4-inch keyways, and the cast-iron housing is sealed to protect the gears and taper roller bearings. The gearbox ships without oil; the description specifies a 1/3-quart fill of 80-90W lubricant for setup.

Skip it if you need a gearbox ready to run without a separate oil fill; this one ships without its specified lubricant.

This unit fits buyers who need its crosshole and keyed-shaft connection combination alongside a 40 HP-rated, 1:1 right-angle drive. Check the mounting dimensions and plan the required oil fill before installation.

Listed on Amazon as: 40 HP Right Angle Bevel Gearbox with Crosshole & 1" Keyed Shaft 19455-SR-KW-PH-GR CW/CW 1:1 1800 Max RPM

#4 · Dual Outputs

4. Holdia Three-Shaft Gearbox

• Weight: 23.2 lb
• Package Dimensions: 13 x 10 x 5.5 in

Best for: Dual-output keyed-shaft layouts.

Why it ranks #4: Its three 1-inch keyed shafts and 1:1 ratio provide two outputs, with the listing specifying CW/CW/CCW rotation and a 40 HP rating.

Three 1-inch keyed shafts and two output directions give this Holdia gearbox a distinctive role in multi-shaft drive arrangements. With 1:1 gearing, clockwise input turns one output clockwise and the other counterclockwise, allowing a layout to branch power in opposite rotational directions.

The 4-1/4-inch square mounting pattern with 3/8-inch tapped holes is repeated on both sides, giving installers options for mounting and arranging the shafts. Each 1-inch shaft uses a 1/4-inch keyway, making the connection dimensions explicit for keyed components. The gearbox is rated at 40 HP input power and up to 1,800 RPM; its CW/CW/CCW behavior is important to account for when planning connected wheels or mechanisms.

Skip it if you need both outputs turning the same way; this gearbox specifies one clockwise and one counterclockwise output.

This Holdia is a fit for projects needing two oppositely rotating outputs, keyed 1-inch shafts, and a 40 HP rating. Confirm that its output directions and two-sided mounting pattern work with the kart’s planned drive arrangement.

Listed on Amazon as: 40 HP Right Angle Bevel Gearbox with Three 1" Keyed Shafts 1:1 1800 Max RPM

#5 · Spiral Gear Design

5. GTPBAO 15mm Spiral Gearbox

• Weight: 100 g

Best for: Spiral-bevel 15 mm drives.

Why it ranks #5: This compact 1:1 unit has 15mm shafts, spiral bevel gears, and a stated recommended speed of 2,000 rpm, but no go-kart capacity rating.

A 15 mm single output shaft paired with 19-tooth spiral bevel gears distinguishes this GTPBAO gearbox for compact right-angle projects. Its 1:1 ratio and stated recommended speed of 2,000 RPM provide useful operating parameters, while the listed 80 mm input and 100 mm output shaft lengths inform layout planning.

The aluminum case supports a lightweight assembly, and stainless-steel 15 mm shafts give the buyer a stated material and diameter for connection planning. Carbon-steel spiral bevel gears provide the specified 1.5-module, 19-tooth gearing for 90-degree transmission at a 1:1 ratio. The separate input and output shaft lengths—80 mm and 100 mm—help estimate clearance and coupling placement, though no input-power rating is supplied.

Skip it if you need a documented horsepower or torque capacity for the kart drive; this listing gives a recommended speed but no power rating.

Consider this GTPBAO for a compact build that needs a 15 mm shaft, spiral bevel gearing, and a stated recommended speed. Its missing power rating makes capacity assessment essential before drivetrain use.

Listed on Amazon as: Gearbox 90 Degree Steering Gearbox 1.5M 19T Spiral Bevel Gear Reversing Corner Device 1 to 1 15mm Output Shaft Commutator Steering Direction

#6

6. tpengine 15mm Bevel Gearbox

Best for: 15 mm shaft mechanical builds.

Why it ranks #6: The 1:1 right-angle unit lists a 15mm shaft and 1.5-module, 20-tooth bevel gears, useful dimensions for checking a smaller mechanical installation.

A 15 mm shaft is the defining connection size of this tpengine right-angle gearbox, making it a candidate for simple mechanical assemblies that use that shaft diameter. Its 1:1, 20-tooth bevel gearing turns power through a 90-degree angle without changing the stated ratio.

The listed 1.5 module and 20-tooth bevel gear specify the gearing, while the 1:1 ratio provides equal input and output speed by ratio. Its 15 mm shaft and right-angle arrangement give a buyer two concrete dimensions to consider when routing a mechanical drive. The supplied information identifies it for simple mechanical applications but does not provide a power rating, speed limit, mounting pattern, or housing material, so those installation needs remain unresolved.

Skip it if you need a gearbox with a published power capacity or RPM ceiling for a kart drive; this listing states neither.

Pick this tpengine unit only when a simple mechanical build calls for a 15 mm shaft and 1:1 right-angle gearing. The available specifications do not establish capacity or mounting details for a kart installation.

Listed on Amazon as: 1:1 Right Angle Tapered Bevel Gearbox 1.5 Module 20 Teeth 90° Angle

#7

7. PGFUN Waterproof Gearbox

• Weight: 1.76 lb
• Package Dimensions: 5.12 x 5.12 x 2.36 in

Best for: Waterproof compact right-angle builds.

Why it ranks #7: Its title identifies a waterproof 1:1 gearbox with 1.5-module, 20-tooth gears, but the supplied data omits shaft dimensions and capacity.

Waterproof construction is the defining listed feature of this PGFUN right-angle gearbox, making it relevant when exposure protection is a priority. Its title also specifies 1:1 gearing, 1.5-module, 20-tooth bevel gears, and a 90-degree drive for compact steering or mechanical arrangements.

The 1:1 ratio indicates no change in speed by gearing, while the 1.5-module, 20-tooth description identifies the bevel gear specification. A 90-degree arrangement provides the stated direction change for a right-angle layout, and the waterproof title may matter where protection from water is a selection criterion. The supplied details do not state shaft diameter, power capacity, RPM limit, mounting pattern, or a specific waterproof rating, limiting installation and duty assessment.

Skip it if you need a specified shaft size and capacity for a kart drivetrain; neither is given in the supplied details.

This PGFUN may suit a compact right-angle project where waterproof construction is central to selection. Before using it in a kart, establish whether its unspecified shaft dimensions and capacity match the intended drive.

Listed on Amazon as: 1:1 Waterproof Right Angle Gearbox 1.5 Module 20 Teeth 90° Angle Drive Steering Gear Device

#8

8. uxcell 10mm Bevel Gearbox

Best for: Compact 10 mm DIY drives.

Why it ranks #8: The 1:1 unit has a 10mm shaft and aluminum frame, but its small shaft and lack of a stated load rating limit evidence for kart use.

A 10 mm input-and-output shaft arrangement in a compact aluminum-frame gearbox makes this uxcell unit suited to smaller mechanical layouts. Its single-output, 20-tooth bevel gears use a 1:1 ratio to turn the drive through 90 degrees without changing the stated ratio.

The listed 68 x 71.5 x 30 mm dimensions help buyers plan space for this small assembly, while its aluminum frame supports lighter handling than the larger cast-iron gearboxes in this roundup. A 10 mm shaft on both input and output gives a clear connection size for a DIY mechanism, and the 1:1 bevel gearing provides right-angle transmission. The product information describes the shaft material as 45# shaft stainless steel, but gives no power or speed rating.

Skip it if you need a stated high-power or RPM rating for a kart drivetrain; this listing supplies neither.

Consider this uxcell gearbox for a compact DIY mechanism with 10 mm connections and a 1:1 right-angle drive. Its listed details do not establish power capacity or operating-speed limits, so those requirements need separate verification.

Listed on Amazon as: uxcell Gear Box 90 Degree Right Angle Bevel Gearbox 1:1 Single Output Shaft 1 Module 20 Teeth Bevel Gear Aluminum Frame Simple Mechanical DIY Module 10mm Shaft,68×71.5x30mm(LxWxH)

#9

9. FTjireyr 12mm Dual-Shaft Gearbox

Best for: Dual-output 12 mm mechanisms.

Why it ranks #9: The 1:1 dual-output gearbox lists 12mm shafts, 2,000-rpm maximum speed, and 20kg maximum force, but lacks a horsepower rating.

Two co-directional 12 mm output shafts set this FTjireyr gearbox apart for mechanisms that need paired outputs turning the same way. Its 1:1 spiral-bevel arrangement transfers drive through 90 degrees, with a stated maximum speed of 2,000 RPM and maximum force of 20 kg.

The aluminum case and stainless-steel shafts specify materials relevant to assembly planning, while the 12 mm shaft diameter identifies the connection size. Carbon-steel, 1.25-module, 19-tooth spiral bevel gears provide the stated gearing, and the dual co-directional outputs support paired-drive layouts. The listing sets a 2,000 RPM maximum and 20 kg maximum force; those limits should be considered alongside the kart’s load and operating requirements.

Skip it if you need a gearbox whose stated maximum force exceeds 20 kg; this unit lists a 20 kg limit.

Choose this FTjireyr for a paired-output mechanism needing same-direction 12 mm shafts and 1:1 right-angle gearing. Its stated 20 kg force and 2,000 RPM limits must suit the planned kart application.

Listed on Amazon as: Mechanical Steering 1pc 90 Degree Spiral Bevel Gear Gearbox 12mm Co-Directional Dual Shaft Right Angle 1:1 Ratio Commutator Direction Transmission

#10

10. PGFUN Mini 8mm Gearbox

Best for: Mini 8 mm steering mechanisms.

Why it ranks #10: Its 8mm shaft and mini DIY description point to a small mechanical application; the supplied specifications do not establish capacity for go-kart loads.

An 8 mm shaft and mini 1-module, 20-tooth bevel gearing make this PGFUN unit the smallest-scale choice in the supplied descriptions. The 1:1 right-angle arrangement targets simple mechanical or steering mechanisms where a compact shaft connection matters more than a documented high-power rating.

The listed 2.2-inch width and 1.2-inch height help when estimating space for a small assembly, while stainless-steel construction identifies the stated material. Its 8 mm shaft and 1-module, 20-tooth gearing point to a smaller mechanism than the 1-inch keyed-shaft gearboxes in this set. The title specifies 1:1 transmission at 90 degrees, but the supplied specifications do not state input power, maximum RPM, or a mounting pattern.

Skip it if you need documented capacity for a high-load kart drivetrain; this mini gearbox has no listed power or RPM rating.

Choose this PGFUN for a compact, small-shaft steering or DIY mechanism requiring 1:1 right-angle transmission. Its 8 mm connection and unspecified power capacity make it a poor match where drivetrain loads must be quantified.

Listed on Amazon as: 1:1 Right Angle Tapered Bevel Gearbox Mini 1 Module 20 Teeth 90° Angle Drive Steering Gear Device Simple Mechanical DIY Module with 8mm Shaft