---
product_id: 98151965
title: "40HP Gearbox 1-3/8\" Smooth Input & 12 Spline Output Shaft for 4' & 5' Cutters Farmer Bob's Parts 49331"
brand: "farmer bob's parts"
price: "A$919"
currency: AUD
in_stock: true
reviews_count: 1
url: https://www.desertcart.com.au/products/98151965-40hp-gearbox-1-3-8-smooth-input-and-12-spline
store_origin: AU
region: Australia
---

# 1:1 Gear Ratio 4 Mounting Holes 40 HP Power 40HP Gearbox 1-3/8" Smooth Input & 12 Spline Output Shaft for 4' & 5' Cutters Farmer Bob's Parts 49331

**Brand:** farmer bob's parts
**Price:** A$919
**Availability:** ✅ In Stock

## Summary

> 🔧 Gear Up for Greatness!

## Quick Answers

- **What is this?** 40HP Gearbox 1-3/8" Smooth Input & 12 Spline Output Shaft for 4' & 5' Cutters Farmer Bob's Parts 49331 by farmer bob's parts
- **How much does it cost?** A$919 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/98151965-40hp-gearbox-1-3-8-smooth-input-and-12-spline)

## Best For

- farmer bob's parts enthusiasts

## Why This Product

- Trusted farmer bob's parts brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built to Last:** Engineered for durability, making it a reliable choice for any farming operation.
- • **Sturdy Mounting:** Features a robust mounting pattern with 4 holes for secure installation.
- • **Unleash Your Power:** Harness 40 HP for maximum efficiency in your cutting tasks.
- • **Precision Engineering:** Designed with a 1:1 gear ratio for optimal performance.
- • **Versatile Compatibility:** Perfectly suited for 4' & 5' cutters, ensuring seamless integration.

## Overview

The 40HP Gearbox from Farmer Bob's Parts is a high-performance gearbox designed for 4' and 5' cutters. With a powerful 40 HP output, a 1:1 gear ratio, and a sturdy mounting pattern featuring four 5/8" holes, this gearbox ensures reliable and efficient operation for all your agricultural needs.

## Description

Mounting Pattern (4) 5/8" Holes x 4-3/4" Centers Designed for use with 4 ft., 5 ft. and 6 ft. rotary cutters, this rotary cutter gearbox has 4 bolt holes measuring 5/8" for installment. Gearboxes work to administer a transfer of speed and torque through their internal gear rotation, helping the overall performance of your rotary cutter.

## Features

- Mounting Pattern (4) 5/8" Holes x 4-3/4" Centers Bolt Holes: 4-3/4" Side to Side 5-1/4" from Bottom of Input Shaft to Base Ratio: 1:1:47
- GB40SM12
- Rotary Cutter Gear Box
- 40 HP
- Black

## Images

![40HP Gearbox 1-3/8" Smooth Input & 12 Spline Output Shaft for 4' & 5' Cutters Farmer Bob's Parts 49331 - Image 1](https://m.media-amazon.com/images/I/51YcO3ZwudL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Perfect
*by D***R on April 18, 2020*

This ad showed all of the specifications which saved me time doing the research with other vendors. Received ahead of schedule and my customer is happy. Will definitely use them again.

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**Shop now:** [https://www.desertcart.com.au/products/98151965-40hp-gearbox-1-3-8-smooth-input-and-12-spline](https://www.desertcart.com.au/products/98151965-40hp-gearbox-1-3-8-smooth-input-and-12-spline)

---

*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-02-25*