Skip the auto shop - Our mechanics make house calls

What Are Leaf Springs?

Leaf spring

A leaf spring is a component of some vehicles’ suspension systems. Specifically, a leaf spring is composed of several (or occasionally just one) thin strips of metal, called leaves, arranged on top of each other to form a single curved piece. The bending of the leaves and the friction between them as they slide slightly over each other while bending, absorbs the vehicle’s weight as well as any bumps. Most leaf springs are curved (these are often called elliptical springs); the curvature helps the spring absorb impact.

The three major functions of any vehicle’s suspension are to:

  • Support the vehicle

  • Absorb impacts from bumps, potholes, and other road irregularities

  • Allow the vehicle to turn in response to the driver’s inputs. (The steering system can be considered part of the suspension, or its own system, but either way the suspension has to allow for movement of the wheels as the vehicle turns).

Springs in general, and leaf springs in particular, help perform the first two of these functions: they support the weight of the vehicle while absorbing bumps.

A leaf spring is usually attached to the body or frame of the vehicle at each end, while the wheel or axle assembly is fixed to the middle of the spring. Usually each spring extends in the same direction as the vehicle, one on each side, with attachment points at the front and rear; a few suspension designs feature a single leaf spring attached at each side (a “transverse” spring).

The purpose of leaf springs

Leaf springs are relatively simple to make and have been used on carts and carriages since long before cars and trucks came into existence. Many of the first cars, including the Ford Model T, employed leaf springs. Leaf springs are appropriate for spreading heavy loads over a large area (because they are attached to the vehicle at the ends, which may be several feet apart) and for suspension designs that incorporate a “solid” axle rather than independent suspension for each wheel, which was common on cars up through the 1970s and is still the norm on heavy vehicles such as trucks.

These factors render leaf springs appropriate for trucks and other heavy vehicles but less so for cars, as such designs tend to have undesirable effects on a vehicle’s handling. As independent (as opposed to solid axle) rear suspensions have become increasingly common on cars, leaf springs are now found primarily on trucks, vans, SUVs, and trailers.

Maintenance of leaf springs

If your vehicle features leaf springs, do you need to worry about them? Probably not, unless they’re quite old. Multi-leaf springs occasionally get “sticky” as dirt works its way in between the leaves; the effect can be to make the ride slightly stiffer, but this is rarely a significant problem. The attachment points will need to be checked periodically and lubricated in some cases (check your owner’s manual), and you’ll want your mechanic to check for broken leaves.

If you drive a classic car you may notice that its body seems to sit too low over the wheels; this sagging is usually due to the leaf springs’ having bent slightly over time, and the solution is to have them replaced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Post a question and get free advice from our certified mechanics.

ASK A QUESTION

More related articles

The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...


Related questions

Q: Leaf spring mount needs to be welded back on

Hi there. This is a difficult question to answer, simply because of the detailed information needed for what portion of the leaf spring mount is damaged or how damaged may have been done to the mount. In general, I'd suggest...

Q: Car noise, dashboard warnings on

One guess is that the problem could be a faulty wheel bearing(s). Bad wheel bearings often result in a rotational growling noise. The wheel bearing is integral to the hub assembly on your vehicle, which also houses the reluctor ring...

Q: What is a leaf spring?

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....