Axles 101: The Insider's Guide to Axle Mechanics
An essential piece of your driving system is connected to your wheels and bears the entire weight of your vehicle. Without it, your vehicle wouldn't move at all!
We're talking about axles.
This part may seem complex (especially as it relates to your vehicle as a whole system), but any vehicle owner needs to understand its function.
In this blog, we will explore:
The difference between the rear differential and axle
How to accurately measure an axle
The potential pitfalls of measuring your axle incorrectly
A common question: Can you replace just an axle?
Whether you're a seasoned car enthusiast or a curious beginner, we aim to shed light on this essential part of your vehicle.
Let's get started with Axles 101!
What Is The Difference Between A Rear Differential And An Axle?
The rear differential and the axle are both essential components of a vehicle's drivetrain but serve different functions and have distinct characteristics. Knowing their differences will help you understand how power is transmitted from the engine to the wheels.
Rear Differential: The rear differential allows the wheels on the same axle to rotate at different speeds, allowing the vehicle to turn smoothly and efficiently. When a vehicle turns, the outside wheel needs to travel a greater distance than the inside wheel, requiring different speeds.
It's located between the drive wheels of the vehicle and is usually part of the rear axle assembly in rear-wheel-drive vehicles. It consists of a series of gears, including pinion, ring, and differential gears.
It receives power from the transmission via the driveshaft, which then transmits this power to the axle.
Axle: The axle bears the vehicle's weight and transmits driving torque to the wheels, providing a place to mount wheels and tires.
There are different types of axles: live axles (which deliver power to the wheels) and dead axles (which don't transmit power and are mainly used for supporting weight). In a rear-wheel-drive vehicle, the rear axle is typically a live axle.
The axle includes components like axle shafts (which may be solid or split, as in the case of a live axle with a differential), bearings, and, in some cases, the housing that encloses the differential.
In rear-wheel-drive vehicles, the rear axle is connected to the differential, receiving torque from it and transmitting this torque to the wheels. Essentially:
The rear differential is responsible for adjusting the speed of the wheels on the same axle for efficient turning
The axle is responsible for carrying the vehicle's weight and transmitting power to the wheels.
In a rear-wheel-drive system, the differential is part of the rear axle assembly, but it performs a distinct function separate from the axle.
How Do You Measure An Axle?
How you measure an axle depends on the axle type. Be sure to get this measurement right, as it's essential to ensure you have an axle shaft that fits your vehicle's specifications perfectly.
Every axle type has specific measurement criteria for determining its length:
Front Axle Shafts: Axles equipped with yokes need to be measured from the exact center of the u-joint bore, extending to the very end of the splines.
Semi-Float Rear Axle: Measure against the outer face of the flange and extend the tape straight to the very end of the axle shaft's tip.
Full Float Rear Axle: Measure from the end of the splines, extending straight to the front surface of the mounting flange.
Before placing an order, consider consulting with a professional, referring to your vehicle's manual for insights or considerations that could affect the measurement process, or selecting the correct axle shaft.
Obtaining the precise measurement of your vehicle's axle length is critical in ensuring you receive the correct parts that will fit and function as intended, maintaining your vehicle's performance and safety on the road.
The Pitfalls of Improper Axle Sizing
If your axle's measurements are incorrect, it can impact your vehicle's performance, safety, and longevity (depending on the nature and extent of the measurement discrepancy).
Here are six potential problems that can arise:
Poor Fit: If the axle is too long or short, it may not fit properly in the vehicle, causing the axle to be improperly seated in the wheel hub or differential, leading to further mechanical problems.
Increased Wear and Tear: An axle that is not the correct length can lead to wear on the axle, bearings, seals, and other drivetrain components, shortening the lifespan of these parts and causing more frequent repairs.
Vibrations and Noise: Incorrect axle length can cause vibrations and noise while the vehicle is moving, causing an uncomfortable driving experience and a vivid reminder that your vehicle needs attention.
Alignment Issues: An axle that doesn't match the required specifications can affect wheel alignment, causing uneven tire wear, handling issues, and decreased fuel efficiency.
Reduced Vehicle Performance: The wrong axle size can negatively impact the transmission of power from the engine to the wheels, reducing the overall performance and efficiency of the vehicle.
Safety Hazards: In extreme cases, an incorrectly sized axle can lead to wheel detachment or failure of other critical components while the vehicle is in operation, posing significant safety risks.
Can You Replace Just The Axle?
Absolutely! You can replace just an axle in a vehicle. It's a common repair, especially in vehicles that have sustained damage due to:
An accident
Excessive wear and tear
Issues related to the axle assembly, such as bent shafts, worn bearings, or damaged joints.
However, replacing an axle (and doing it correctly) requires special equipment and comes with safety concerns - it's best to leave this one to the professionals!
We’re Here For You
Understanding the complexities of vehicles and their numerous parts can be challenging. However, you don't need to navigate this alone – we're here to guide you. Our expertise covers everything from the intricacies of your vehicle and its various components to identifying its specific requirements.
Rest assured, with Midwest Transmission, you'll find all the essential parts your vehicle requires. Our motto says it all: from the flywheel to the drive wheel, we've got everything you need.