Common Failures Of Bad Leaf Springs: Symptoms!
There are many different types of suspension designs in use today, one of which is a leaf spring style system. Leaf spring suspensions are typically found on light trucks (ie pickup trucks, vans, etc.) and some older rear wheel drive cars. If you wish, you can read and learn more about the common failures of leaf springs in poor condition, so that you know about the problem.
Although leaf springs are designed to last the life of the vehicle, they can wear out over time, especially when subjected to heavy loads or harsh winters and salty roads. When that happens, you’ll likely notice some undesirable symptoms that you’ll want to fix right away.
What is a crossbow?
Leaf springs are the oldest type of vehicle suspension spring, dating back to the days of horse-drawn carriages. A crossbow has one or more layered strips of steel (or fiberglass-reinforced plastic), called blades . The sheets have rubber or plastic insulators between them.
There is a leaf spring on each side of the suspension. Each end of the crossbow has an eyelet with a bushing inside. A screw goes through each eyelet to secure the leaf spring to the vehicle.
Typically, one end of the leaf spring connects directly to a hook on the frame, and the other end connects to a shackle, which, in turn, connects to the frame. The shackle allows the leaf spring to move slightly when the vehicle goes over bumps. A center bolt holds the blades together, and a set of U-bolts and accompanying hardware secure the leaf spring to the vehicle’s axle box.
Leaf springs are often used on the rear suspension of light trucks and some vintage cars. Many four-wheel drive vehicles with a solid front axle also use leaf springs on the front suspension.
Symptoms and Common Failures of Bad Leaf Springs
Do you think that the leaf springs of your vehicle may be damaged or worn? If you notice one or more of the following symptoms, you might be correct and it is a common fault with bad leaf springs.
Note: Many other problems can mimic a bad crossbow. You (or your mechanic) should perform a thorough diagnosis before doing any repairs.
1. Abnormal noises in the undercarriage
The most common symptom associated with a bad leaf spring is abnormal noise from the undercarriage. Depending on the problem with the leaf spring, a squeak or pop may be heard. The problem is usually more noticeable when going over potholes .
2. Sagging suspension
Worn rear leaf springs can cause visible suspension sag, causing the vehicle to sit lower than normal on one or both sides. The vehicle may also “bottom out” when going over potholes.
3. The “dog tracking” of the vehicle
If the leaf springs or related hardware is compromised, the rear axle box can shift position, causing the vehicle to “track” while driving on the highway. “Dog tracking” indicates that the wheel alignment thrust angle (the angle of the vehicle’s center line compared to the road) is off . If you look at the vehicle from behind, the rear tires will appear to move to the sides while the front tires point forward.
4. Visible damage
Good leaf springs are usually elliptical in shape, with the apex of the curve pointing downward. But when the leaf spring wears out, you may notice the curve arching up or the leaf spring becoming almost flat.
Leaf springs can also sustain other visible damage such as cracks, severe rust, and rotted eyelet bushings.
Questions and answers
It is normal that after reading about the problems that this piece can generate, you have a few doubts in mind, so we have selected the most frequently asked questions and have answered them for you.
1. How is a leaf spring checked?
If you think there may be a problem with your vehicle’s leaf springs, you’ll want to perform a visual inspection, looking for obvious signs of damage, such as cracks and broken blades. You’ll also want to check the eyelet sockets (for dry rot and other damage), shackles, and frame brackets.
2. How long do the crossbows last?
Leaf springs are designed to last the life of the vehicle, but that’s not always the case. Leaf springs often fail prematurely due to rust and corrosion . Overloading the vehicle or carrying heavy loads on a regular basis can also strain the leaf springs, causing them to fail sooner than normal. Additionally, eyelet bushings can suffer from dry rot and other damage after years of exposure to the elements.
3. Do the crossbows get weak?
Leaf springs can become weak over time due to rust or carrying heavy loads. To maintain the safety and reliability of your vehicle, weak leaf springs should be replaced immediately.
