Skip the auto shop - Our mechanics make house calls

Q: What is a leaf spring?

asked by on

What is a leaf spring?

A: A leaf spring is a suspension support made ...

A leaf spring is a suspension support made up of long metal strips bent into an arc or elliptical shape with multiple pieces attached one on top of another as determined by the overall weight the spring is to support.

These type of springs have been used since medieval times and were known by many other names including carriage springs. These springs are used today in some automotive vehicles but are primarily used in truck and trailers. They support the weight of the assembly by allowing the load to be carried safely while traveling on or off road. Each individual spring element or leaf is combined in different lengths and the overall number of leaf components depend on the rated weight limit of the particular vehicle.

They are indexed or kept in alignment for assembly using a center bolt and bound together with clips that secure the leaves. The entire assembly is joined to the frame of the vehicle by bolts through metal brackets called shackles, which reside in hangers bolted or welded to the frame of the vehicle.

The main signs of spring failure include squeaking noise when the vehicle is going over bumps or cracking sounds if one or more leafs has broken. The rebound clips can rust out and allow the spring elements to shift, which can make them hit or contact on the frame of the vehicle. Also, inside the shackle ends are bushings which support the assembly. These bushings can wear, causing noise or shifting of the springs which can be felt when starting out or stopping. Like cylindrical springs they are exposed to repeated compression and relaxation which will weaken over time. This causes sagging on the side of the axle they are attached to as the resultant wear may not be even on each spring.

The proper repair for damaged or defective springs is to replace them as a set on whatever axle they are on. By doing so, the ride height, cushion, or stability they offer is evenly returned to factory specifications.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car door not shutting

Hello. It sounds like your door stay has come apart, and is not allowing the door to close. The only repair is to replace the door hinge that has the door stay built into it. Servicing a door that will...

Q: Front end damage from hitting a curb. Left front wheel/suspension damage.

Hi there. I'm sorry to hear about the damage incurred on your car. This task is best handled by a collision repair estimator at a reputable paint and body shop. They are trained to evaluate visible and not-so-visible damage, and...

Q: 2004 Ford Explorer unstable at 65-80 mph

First thing you'd want to do is change the shocks and struts on it. When they are worn, and the wind blows, it's going to go to go all over the place. It's going to start moving too far to...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.