How do I check the height adjustment is working on my Petrol Lawnmower

This guide explains how to check the height adjustment system and ensure it is working correctly.

Table of Contents

1. How the Height Adjustment System Works
2. Checking the Adjustment Lever
3. Checking the Height Adjustment Spring
4. Inspecting the Connecting Rod

How the Height Adjustment System Works

Most petrol lawnmowers use a mechanical linkage system that adjusts the height of both front and rear wheels simultaneously.

This system typically includes:

• A height adjustment lever
• A spring-loaded locking mechanism
• A connecting rod between axles
• Front and rear axle mounting points

If any part of this system becomes loose, disconnected, or obstructed, the height adjustment may not function correctly.

Checking the Adjustment Lever

Step 1 – Test Full Movement

Operate the height adjustment lever through its full range of motion.

Move the lever forward and backward (or up and down, depending on model) and check for:

• Smooth movement
• Even resistance throughout the range
• No sticking or binding

Step 2 – Check Locking Action

Ensure the lever:

• Returns correctly into position
• Locks securely into the height selector teeth
• Does not slip out of position during use

If the lever does not lock properly, a missing or displaced spring may be the cause.

Checking the Height Adjustment Spring

The height adjustment spring helps maintain tension and ensures the lever locks into the correct position.

Inspection Steps:

• Check that the spring is present and correctly fitted
• Ensure it is not stretched, broken, or detached
• Confirm it is providing sufficient tension to hold the lever in place

If the spring is missing or damaged, it should be replaced before further use.

Inspecting the Connecting Rod

The connecting rod links the front and rear axle assemblies, allowing them to move together when adjusting cutting height.

Location

The rod is typically located along the side of the mower deck, often on the left-hand side, running between the front and rear axles.

What to Check

Ensure that:

• The connecting rod is securely attached at both ends
• The rod is not bent or damaged
• The front and rear axle connection points are intact

Connection Points

Check that:

• Cotter pins and spring clips are fitted correctly, or
• Bolts and nuts (depending on model) are tight and secure

If any of these components are missing or loose, the height adjustment system may not function correctly.