---
product_id: 14755757
title: "Omni Gear Rotary Cutter 40 hp Gear Box 1 3/8\" X 6 Spline Input Shaft"
brand: "omni gear"
price: "A$769"
currency: AUD
in_stock: true
reviews_count: 8
category: "Omni Gear"
url: https://www.desertcart.com.au/products/14755757-omni-gear-rotary-cutter-40-hp-gear-box-1-3
store_origin: AU
region: Australia
---

# Heat-treated gears & shafts 1 3/8" x 6 spline input shaft 40 HP power-packed gearbox Omni Gear Rotary Cutter 40 hp Gear Box 1 3/8" X 6 Spline Input Shaft

**Brand:** omni gear
**Price:** A$769
**Availability:** ✅ In Stock

## Summary

> ⚙️ Upgrade your rotary cutter with power and precision — don’t get left behind!

## Quick Answers

- **What is this?** Omni Gear Rotary Cutter 40 hp Gear Box 1 3/8" X 6 Spline Input Shaft by omni gear
- **How much does it cost?** A$769 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/14755757-omni-gear-rotary-cutter-40-hp-gear-box-1-3)

## Best For

- omni gear enthusiasts

## Why This Product

- Trusted omni gear brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Precision Fit:** Industry-standard 1 3/8" diameter x 6 spline input shaft guarantees compatibility with most rotary cutters.
- • **Complete Kit Ready:** Includes blade carrier mounting nut and cotter pin for hassle-free assembly and secure operation.
- • **Durability Engineered:** Heat-treated gears and shafts combined with high-speed ball bearings deliver long-lasting reliability.
- • **Seamless Installation:** Four-bolt mounting pattern matches industry standards for straightforward replacement and upgrades.
- • **Powerhouse Performance:** 40 HP capacity ensures robust rotary cutter operation for demanding tasks.

## Overview

The Omni Gear Rotary Cutter Gearbox delivers a 40 HP capacity with a 1:1.47 speed-up ratio, featuring a standard 1 3/8" x 6 spline input shaft and a 1.57" diameter tapered spline output shaft. Built with heat-treated gears and high-speed ball bearings, it ensures durability and smooth operation. Designed for easy installation with a four-bolt mount and includes essential hardware, this gearbox is ideal for 5' and larger rotary cutters, offering a reliable upgrade that outperforms many OEM replacements.

## Description

This gearbox features a 1:1.47 Speed Up gear ratio for use on 5' and larger diameter rotary cutters. Industry standard 1-3/8" Diameter X 6 Splined input shaft and 1.57" diameter 12 tapered spline output shaft allow fitment to most light, standard and medium duty rotary cutters. Each gearbox features high speed ball bearing units and heat treated gears and shafts to ensure long life. Four bolt mounting matches industry standards. Each gearbox includes blade carrier mounting nut and cotter pin. Gearboxes are shipped dry and require 16 ounces of 80-90W gearlube or equivalent. Disclaimer: Any and all Original Equipment Manufacturer's (OEM) tradenames, trademarks, drawings, colors, descriptive information and part numbers are used for parts identification purposes only, and DN Equipment, LLC (DN) is in no way implying that any specific parts are OEM parts. Further, any use of the OEM's tradenames, trademarks, drawings or part numbers by DN is designed only to aid DN's customers, in obtaining the proper DN part or component which will replace the OEM's part.

Review: Better than original - Replaced the gearbox for a wolverine brush cutter. Pretty much a straight swap, input shaft is about a quarter inch longer than original. Just had to drill new holes in the mower. Runs much better than the original. Put typhoon tape on the oil plug! Lost mine within minutes! Just a standard 1/2” pipe male cap
Review: WORKS ON WOLVERINE BUSH HOG WITH ADJUSTMENTS - Put this on my Wolverine Bush Skid Bush Hog. Few adjustments to get it to work properly. 1. The drive spline needs cut shorter. I cut it right where the notch in the spline is. That worked good. 2. Gear box is like 1/16- 1/8 lower than the motor. Added washers under the gear box for each bolt and that lined it up perfect. 3. The motor and gear box gears touched upon install. You need about 3/8 space between the gears for the linkage chain to seat properly. I just shimmer the motor back with some washers. Better solution would be to cut out and 1/4 spacer plate to sit between motor and mount or move motor mount back. The factory gear box holes lined up exactly. The blade arm also mounted with no problems. The only thing I might do also is drill a hole in the blade spline for a pin. It comes with a castle nut but isn't drilled to allow a Cotter pin.

## Features

- 40 HP
- Spline
- Gearbox
- Rotary Cutter

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00J351HJQ |
| Best Sellers Rank | #386,083 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #100 in Gearboxes, Gearheads & Speed Reducers |
| Date First Available | March 18, 2014 |
| Item Weight | 44 pounds |
| Manufacturer | Omni Gear |
| Product Dimensions | 15 x 9 x 15 inches |

## Images

![Omni Gear Rotary Cutter 40 hp Gear Box 1 3/8" X 6 Spline Input Shaft - Image 1](https://m.media-amazon.com/images/I/41NVU9W7G4L.jpg)

## Questions & Answers

**Q: will this replace a gear box for a farm king finish mower part #912300158**
A: No, this is for a rotary cutter. The Farm King Finish Mower gearbox will use a keyed output shaft, where this is splined. Are there any numbers on the gearbox itself?

**Q: Need gear box for rottary tiller 48 inch**
A: Unfortunately I do not carry any tiller gearboxes here.

**Q: Do you have a gear box that will fit a John Deere medium duty model 616 bush hog?**
A: The 516/616 is a weird gearbox. it has a 6 bolt mounting pattern like a heavy duty gearbox and a 1.57" 12 spline output shaft like a 40hp box. For any gearbox that will fit the stump jumper, (blade holder), you will have to redrill the deck to mount it. Your box also has a longer output shaft the the standard aftermarket boxes, and the average replacement shaft may not be long enough for the blades to clear the deck well. If you want to explore this further, contact me at dawson@tractors-equipment.com. I would like to know how far the shaft extends below the deck.

**Q: Will this work on a Rhino SE 6 mower?**
A: This is a 40 hp box and it will fit. If you have a slip clutch order the one with a 6 spline input shaft. If it uses a shear bolt order the one with a smooth input shaft.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Better than original
*by D***. on July 17, 2025*

Replaced the gearbox for a wolverine brush cutter. Pretty much a straight swap, input shaft is about a quarter inch longer than original. Just had to drill new holes in the mower. Runs much better than the original. Put typhoon tape on the oil plug! Lost mine within minutes! Just a standard 1/2” pipe male cap

### ⭐⭐⭐⭐⭐ WORKS ON WOLVERINE BUSH HOG WITH ADJUSTMENTS
*by S***N on May 10, 2025*

Put this on my Wolverine Bush Skid Bush Hog. Few adjustments to get it to work properly. 1. The drive spline needs cut shorter. I cut it right where the notch in the spline is. That worked good. 2. Gear box is like 1/16- 1/8 lower than the motor. Added washers under the gear box for each bolt and that lined it up perfect. 3. The motor and gear box gears touched upon install. You need about 3/8 space between the gears for the linkage chain to seat properly. I just shimmer the motor back with some washers. Better solution would be to cut out and 1/4 spacer plate to sit between motor and mount or move motor mount back. The factory gear box holes lined up exactly. The blade arm also mounted with no problems. The only thing I might do also is drill a hole in the blade spline for a pin. It comes with a castle nut but isn't drilled to allow a Cotter pin.

### ⭐⭐⭐⭐⭐ It works well
*by F***Y on November 4, 2025*

It is very well built

## Frequently Bought Together

- Omni Gear Rotary Cutter 40 hp Gear Box 1 3/8" X 6 Spline Input Shaft
- Replacement Bush Hog Rotary Cutter Blade Bolt Kit Code 63607, 2 Bolts with Nuts and Lock Washers
- Replacement Bush Hog Rotary Cutter Blades – Part Number 7555, 24’’x3/4’’ Rancher Supply Blades and Compatible Rotary Replacement Blades for Brush Mowers (2 Blade Set)

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-03-01*