The Ford F-150 was introduced in 1948 and holds the distinction of being the best selling truck in the US for the past 42 years. (Think about that for a moment.) It is also recently became the first production truck with an all aluminum body. Of course, beauty is more than skin deep. Ford designed this vehicle to be rugged with very durable axles.
How Axles Work
In simple terms, an axle is a central shaft for rotating gears or wheels. F-150s usually have four wheel drive, so most have front and rear axles. But the front and rear axles have different designs:
Front - The front axle is really comprised of left and right side axle shafts. The axle shafts don't bear any weight, and only transmit power to the front wheels. A number of components are part of the axle shaft assembly:
- Inboard and outboard oil seals
- CV joint
- CV boots
- CV boot clamps
Rear - The rear axle in a F-150 is called a solid axle, which means that it bears weight. The solid axle in a F-150 is also a "live" axle, because it transmits power to the wheels. A solid axle is comprised of:
- Axle tubes welded to a differential housing
- Differential cover
- Axle shafts that run inside the axle tubes
- Differential gears that transmit power from the driveshaft to the axleshafts
- Wheel bearings in the outer end of the axle tubes
- Oil seals
These are just some of the many axle parts and accessories we carry at FordPartsOnSale.com
Signs of a Bad Front Axle Shaft
1) Clicking Noise
The most common sound indicating an axle shaft has seen better days or needs repair is a loud clicking noise when turning. This is usually due to a bad CV joint. The noise is caused by loose joints that click against each other. They usually become louder during sharper and faster turns.
2) Grease on the Edge of the Tire
Grease on the inside sidewall of a tire can be another tell-tale sign of axle problems. An inspection can also discover it along the vehicle’s underside. Torn boots can leak grease. As the axle turns, it flings grease around. Damaged boots usually mean there is a CV joint about to fail. The tear in a boot allows dirt and moisture to get inside where they will eventually damage the joint.
3) Excessive Vibration
Excessive vibration from the CV axle can also be a sign of impending trouble. If you suspect that your axle needs repair or fixing, it is highly recommended to take it to a qualified mechanic. While backyard mechanics can do a good job on certain repairs, the axle shaft is challenging to remove.
Signs of a Bad Rear Axle
Under normal use, many rear axles last the life of the truck and never need repair. Trucks that see off road use or many heavy loads may need repair eventually. Here is a short list of typical symptoms:
1) Low Pitched Howling
If a rear wheel bearing fails, it will usually make a low pitched howling sound. If it gets bad enough, the truck may pull to one side.
Differential gears whine when they begin to fail.
3) Wheel Wobble
Sometimes a rear axle shaft will get bent right where it exits the axle tube. If this happens, the rear wheel will wobble as it turns.
What Warranties Cover
If you think your axle or axle shaft is going bad, check to see if your vehicle’s powertrain warranty is still active. New Ford F-150 vehicles come with a factory warranty of five-year/60,000-miles for the powertrain. This will provide coverage for the transmission, engine, and more. Roadside assistance that includes towing and other services is also desirable. Your Ford dealer can provide more information.