What’s the difference between a shock and strut?

Shocks and struts perform a similar function but vary greatly in their design. Struts are an integral part of a vehicle’s suspension system, providing structural support for the vehicle and, as such, are a safety subsystem. Shocks work separately from any structural function, simply absorbing and damping the bumps from the road.

What do shocks and struts do?

Shocks and struts play an integral role in your vehicle’s suspension system. They are designed primarily to give you a much smoother ride by absorbing and damping feedback from the road. Keep in mind, automotive shocks and struts do more than just provide a comfortable ride.

One of their most important functions is to influence the control and handling characteristics of your vehicle. They work to keep your tires on the road and to keep you safe and comfortable. Without them, a vehicle would continually bounce up and down, making handling and steering of the vehicle extremely difficult, as well as dangerous.

Vehicle ride control, safety, and a driver’s ability to steer and brake depend on having firm contact between the vehicle’s tires and the road. Shocks and struts aid in ensuring this contact remains secure under any driving condition.

Do gas charged shocks or struts contain oil?

Yes, all shocks and struts use hydraulic fluid (oil) to control damping. A gas charged shock or strut uses high-pressure nitrogen gas to reduce oil foaming during high-speed damping, and therefore maintains performance.

I have a light film of oil on my shock or strut, does it need to be replaced?

Probably not. “Misting” is a common occurrence and totally normal in shocks and struts. In fact, shocks and struts are designed to mist slightly. This oil “mist” lubricates the seal as the rod moves, maximizing shock and strut life. A secondary benefit is additional rod corrosion protection. A small amount of oil on the box is normal. However, if there is an excessive amount of oil on the shock or strut, if oil is running or dripping down the side, or if the box is saturated, the shock or strut may be defective and may need to be replaced.

My tires are unevenly worn. Do I need to replace my ride control components?

Possibly. There are many factors that can contribute to uneven tire wear; the most common cause is a wheel alignment. Worn ride control components can also contribute. Cupping of the tires is commonly seen as an indicator of worn ride control components. However, other types of tire wear can also be caused by worn ride control parts.

Why is it important to replace worn shocks or struts?

As shocks and struts degrade slowly over time, so does the performance and control of your vehicle. Shocks and struts play an essential role in your suspension system; keeping your tires on the road during daily driving conditions and aid in preventing your tires and other suspension parts from becoming damaged and worn out. If shocks or struts aren’t replaced, all ride control elements are affected. Your stability, steering, tire contact with the road, and ability to stop are all affected and greatly reduce driver safety. For maximum comfort, control, performance and safety it is essential to replace your shocks and struts at regular intervals.

Do shocks and struts wear out?

Yes, shocks and struts do wear out. They will rarely fail completely, but wear and tear is a gradual process that happens over time. A shock can be composed of up to 40 precision engineered parts, which include: valves, valve seats and springs, pistons, a piston rod, and a number of high precision parts and seals. All of these components are susceptible to wear and tear over time. That’s why Gabriel® recommends that you have your shocks checked by a qualified service technician every 12 months or 12,000 miles.

How can I check my shocks?

To check your shocks Gabriel® advises that you take your vehicle to your local service technician and let them do an inspection. If you want to do a quick check yourself, you can look for any physical damage to the shock or strut housing or any leaking – this is especially common on rear units that tend to have stones kicked up by the front wheels. Gabriel recommends you have your shocks professionally checked by a qualified service technician every 12 months or 12,000 miles.

When should I replace my shocks?

Generally, Gabriel® recommends replacing your shocks or struts at regular 50,000-mile intervals to ensure a safer and more comfortable ride in most vehicles. Actual mileage intervals may vary based on vehicle, manufacturer’s specifications, vehicle use and environment. However, shocks and struts should be replaced for a number of reasons:

• To improve or upgrade performance or restore original performance
• If the vehicle suffers from excessive lean, sway or bouncing, nose-diving when braking, uneven tire wear, etc.
• If the housing becomes damaged or dented, this may cause leaks that will affect the shock or strut’s performance

When I drive on rough roads or go over speed bumps, I hear a banging noise coming from my suspension. What’s the cause of this?

This could be caused by a missing jounce bumper, which is an elastomeric part that absorbs the energy when two metal parts bump together. There could be other causes, so it’s important to contact your local technician for an inspection or immediate replacement.

What other components should I ask the technician to look at when I have my shocks or struts serviced?

If you are having your shocks and struts serviced or replaced, all other parts of the shock or strut assembly should be checked. These may include the upper mount, bearing, strut bumper, strut boot, coil spring and spring isolator(s). In addition, connecting nuts and bolts should be checked, as they also undergo much wear and tear. If you are replacing a strut and are concerned about the durability of any of these older components, consider a Gabriel® ReadyMount®. A ReadyMount offers a state-of-the-art, completely pre-assembled strut assembly with all-new, high quality upper mount, coil spring and other component parts in one easy-to-install package. It saves time and labor costs resulting from multiple rebuilds and teardowns.

Should I have my vehicle aligned after replacing my struts?

Yes. Unlike shock absorbers, a strut is a structural part of your suspension and steering subsystems; directly influencing your vehicle’s alignment. It is highly recommended to have your vehicle aligned after your struts are serviced. Failure to do so may result in uneven tire wear, a drop in fuel economy and excessive wear on other suspension components.

Can I mount my shock absorber upside down?

No. With the exception of a few specialty shocks, you should never mount your shock absorbers upside down. Typical twin-tube shocks are simply not designed to function upside down for many important reasons. Attempts to do this will likely result in poor shock performance, premature failure and potential damage to your vehicle.

I’m trying to replace my shocks but they don’t seem long enough. Do I need longer shocks?

In some cases you only need to support the lower control arm to shorten the distance, while you connect the shock. Many vehicles are designed to use the length of the shock absorber as a limiter for suspension travel. Gabriel® also recommends that you measure the ride height before performing any suspension work. It can indicate other problems if it is out of specification. A lower than specified ride height might indicate that your vehicle has worn springs. A taller than specified ride height might indicate that a lift kit is installed on the vehicle.

Can I adjust the torsion bars on my truck to compensate for a snow plow?

Yes, as long as you return the vehicle to its original ride height when you remove the snow plow. Premature shock absorber failure is likely if you do not return the vehicle to its original ride height after removing the snow plow.

What can I expect from my new shocks and/or struts?

Your new shock or strut will:

Increase driver comfort and control.

• New shocks are better equipped to keep the vehicle’s tires on the road, which increases control of the vehicle

• New shocks help soften the harshness of an uneven road making the drive more pleasant

• New shocks can also help prevent the vehicle from excessive leaning on turns, nose-diving on stops or veering in crosswinds, providing a more controlled and smooth ride

Reduce tire wear.

• New shocks/struts will reduce tire wear and potentially increase your tires’ life. Worn suspension components, such as old shocks and struts, cause your suspension to move excessively, resulting in additional and sometimes uneven wear on your tires.

Decrease stress on – and increase the life of – other key components and systems.

• When tires lift off the road and then fall back down, it generates substantial energy which the rest of the vehicle components must absorb, thereby causing excessive wear and tear on these other parts, pieces and systems

• One of the key functions of shocks and struts is to absorb the energy and harsh road conditions of everyday driving and to isolate it from reaching the rest of the vehicle. If shocks are old and performance is reduced, this function is compromised, causing other components to experience extra wear. Example: when a car with worn shocks or struts nose-dives while braking, this causes extra wear on the front brakes.

• Worn shocks may also cause the vehicle to move excessively, which causes additional wear on pivot points of the vehicle, such as when a car leans or sways excessively in turns, or veers in side winds

Your new shock or strut will not:

• Determine your ride height.

  • With the exception of a few specialty shock products, ride height is determined by your springs, other suspension components, and the vehicle’s original design and construction

• Cause or fix vibrations.

  • Vibrations are ongoing and are caused by rotational forces in the drive train, wheels and tires. The only way to reduce/remove vibrations is to repair their cause. A shock or strut works by damping the impact of individual forces as they occur, such as sudden pavement bumps or potholes. It is not designed to correct repetitive, ongoing problems with other systems.

• Increase load carrying capacity of your vehicle.

  • The maximum carrying capacity is the GVWR (Gross Vehicle Weight Rating) typically listed on the door jamb. This GVWR number, minus the weight of the vehicle, is the amount of additional weight the vehicle is designed to safely carry, stop with, etc. (For example a vehicle weighing 4,000 lbs. with a GVWR of 6,000 lbs., can carry 2,000 pounds of gear, passengers, etc.).

  • Putting in an air shock does not increase you GVWR. This is because the vehicle, its components and systems (tires, brake system, bearings, transmission system) are only designed to handle the listed GVWR.

  • There are specialty shocks which help keep your vehicle level under other conditions, such as while towing or when in a temporarily overloaded state, but these will not increase its rated capacity (GVWR).

I have just replaced and fitted new shocks, so why does my car feel very stiff on the road?

Many drivers are quick to forget how a good shock absorber should work. As old shocks become worn over time, they ride softer and drivers tend to adjust their driving style to compensate for this. New Gabriel® shocks return the car to its original ride. It’s important you seek a Gabriel replacement shock or strut with the ride performance that meets your needs.

What is an Ultra™ Cartridge?

A typical strut must be replaced as an entire unit. The hydraulic wear-out items – piston, seals, tube and rod – are contained in the tube-and-rod assembly, which is permanently enclosed in the strut body. In some strut designs, however, these wear-out items can be replaced or upgraded separately, with a new cartridge. A Gabriel® Ultra™ Cartridge is a self-contained tube-and-rod assembly, with all new hydraulic components, to replace your worn-out parts. Because it is an Ultra design, you can be sure that it has a chromed piston rod and G‑Force™ Technology, providing you with superior corrosion protection and the perfect combination of safety, performance and control in your car’s ride.

What is an Ultra™ Spring Seat Shock?

A Gabriel® Ultra™ Spring Seat Shock is a variation on the conventional shock absorber design that uniquely features a Striker Cap at the top of the shock body. This separate metal cap is designed to take the impact of the jounce bumper or bump-stop when the shock is near full compression. In some designs, the Spring Seat Shock includes a spring seat – this type of design is sometimes called a “coilover shock.” Similar designs may also be referred to as “mini-struts.” At Gabriel, however, we call all of these designs Ultra Spring Seat Shocks. And like all Ultra products, they are built with chromed piston rods and G‑Force™ technology to restore the ultimate in safety and performance to your car’s ride.

FAQs about rebuilding struts:

Is my strut rebuildable?

• Some struts are rebuildable and some are not. Many OE struts are rebuildable. Here are a few ways to determine if they are:

• If the strut has a cutline groove stamped into the top of the strut body (painted area) and wording stamped that says “cut here.” Be sure not to cut any strut open unless it specifically has “cut here” stamped into the strut body.

• Others may have a hex-shaped locking ring on the top of the strut body (painted area). Another way to tell if they are rebuildable is if there are threads visible on the outside top of the strut body (painted area).

What kind of oil should I use in the housing?

• We recommend using transmission fluid in the housing because the fluid’s color is red. This distinguishes it from the oil in the cartridge – which is not – and if there happens to be any fluid overflow, a determination can be easily made as to which fluid it is.

It says to fill the housing with 30 cc. How much fluid is this and how much should I put into the housing?

• 30 cc is the equivalent of 1 fluid once. Start with this amount in the housing before you place the strut cartridge in. Use the cartridge as a dipstick. The body of it should have oil ¾ of the way up the sides when fully inserted. You may need to add more oil, in small amounts, until you reach this level.

Click here for FAQ's about air shocks/air leveling systems. 

GABRIEL CANNOT DETERMINE WHETHER ANY PARTICULAR CUSTOMER IS QUALIFIED TO CHECK OR REPLACE RIDE CONTROL, SHOCKS OR STRUTS. CUSTOMERS MUST MAKE THEIR OWN ASSESSMENTS OF THEIR EXPERIENCE, SKILLS AND KNOWLEDGE AND TAKE RESPONSIBILITY FOR ALL RESULTS AND IF IN DOUBT, SEEK THE ASSISTANCE OF A QUALIFIED TRAINED MECHANIC.

THESE VIDEOS ARE NOT INTENDED TO BE STEP-BY-STEP INSTRUCTIONS, BUT ARE INTENDED FOR GENERAL INFORMATION PURPOSES ONLY.

EVERY VEHICLE IS DELIVERED WITH AN OEM OWNER’S MANUAL. IF YOU CANNOT LOCATE YOURS, SEVERAL PUBLICATIONS EXIST THAT WILL PROVIDE YOU WITH THE SPECIFICATIONS FOR THE PARTS ON THE VEHICLE YOU ARE ABOUT TO REPAIR. READ THE OEM MANUAL SPECIFIC TO THE MAKE AND MODEL OF YOUR VEHICLE AND THE INSTRUCTIONS THAT ACCOMPANY YOUR GABRIEL PRODUCT BEFORE UNDERTAKING ANY REPAIR OR REPLACEMENT PROJECT. ALWAYS SEEK THE ADVICE OR ASSISTANCE OF A QUALIFIED, TRAINED PROFESSIONAL WHEN NEEDED.

BEFORE STARTING AND VEHICLE REPAIR OR REPLACEMENT PROJECT, YOU MUST HAVE THE PROPER TRAINING, TOOLS, EQUIPMENT AND EXPERIENCE NECESSARY TO SAFELY AND CORRECTLY COMPLETE THE PROJECT. THIS IS ESPECIALLY IMPORTANT FOR ANYONE ATTEMPTING TO REPLACE A WORN STRUT OR SHOCK ABSORBER, BECAUSE FAILURE TO REMOVE THE WORN PART OR INSTALL THE REPLACEMENT PARTS CORRECTLY ON YOUR VEHICLE MAY RESULT IN PERSONAL INJURY OR DAMAGE TO PROPERTY.