frequently asked questions

What causes my vehicle to make clunking noises even though my shocks/ struts are new?

• This is usually caused by a mounting problem and not the shock or strut itself. Check the components that attach the shock or strut to the vehicle.

• The mount itself may be worn enough to cause the shock/strut to move up and down. Another common cause of noise is that the shock or strut mountings may not be tight enough causing the unit to have some slight movement between the bolt and bushing or other attaching parts.

Do the strut mounts come with the bearings?

• Many do, but only when the strut mount is also the steering pivot. The bearing is a wear item and affects the steering response as well as wheel alignment. See the KYB catalog for application part number and a picture of each item.

I can compress my shock/strut too easily by hand. Does this mean the shock/strut is weak or defective?

• You cannot judge the strength or condition of a shock/strut by hand movement alone. The force and speed generated by a vehicle in operation exceeds what you can accomplish by hand. The fluid valves are calibrated to operate differently depending on the degree of movement inertia which cannot be duplicated by hand.

Can worn shocks or struts cause my new tires to wear unevenly?

• Absolutely: shocks and struts provide damping force to control tire movement. When the tires move excessively, they develop a “cupping” wear pattern that damages the tire.

• Other factors such as incorrect air pressure, worn suspension components or improperly aligned steering also causes uneven tire wear.

My vehicle is equipped with electronic or air suspension. Can it be converted to use standard gas shock/struts?

• KYB offers a substitute or conversion for some vehicles.

What is the difference between original equipment KYB and the aftermarket KYB components?

• Original equipment KYB shock and struts are designed to the OE manufacture’s specifications. Although built on the same assembly lines, the aftermarket KYB products are calibrated to compensate for worn suspension components to help restore the vehicle’s original handling and control characteristics.

• KYB aftermarket also offers monotube shocks which for most vehicles will provide additional control and handling capabilities.

When do I need to replace worn shocks or struts?

• There are four main reasons that determine when to replace them:

1. To upgrade performance;

2. to restore the vehicle’s designed performance (usually after 50,000 miles);

3. when the vehicle has excessive ride control conditions (i.e. nose dive, body roll, etc.);

4. when the vehicle has a failed unit (i.e. dripping hydraulic fluid, tire cupping, excessive bounce, etc.).

I noticed a light film of oil on the shaft of my shock/strut do I need to replace them?

• Probably not; a small amount of oil is normal and is used to lubricate the polished shaft and the upper seals. However if the unit is extremely wet or dripping oil, the unit should be inspected by a qualified technician.

Should I consider replacing any other part while having my struts serviced?

• Yes, it is also a good idea to replace both the strut mount and the strut boot when replacing struts. The strut mount optimizes suspension performance by providing a smooth steering response and reducing vibration. Strut boots will protect your new struts from dirt, dust, salt and leakage.

What is the difference between a monotube and a twin-tube design?

• By far, most vehicles (cars & trucks) in the world came factory-equipped with a twin-tube style shock or strut; probably 85% or more. The twin-tube is cost-effective and performs very well when the vehicle is operated within its designed purpose and for average, every-day use. In many other model vehicles, when the manufacturer designs a vehicle for more than average driving conditions, they often choose a monotube style shock. It's a bit more costly, but has a quicker response rate, has no performance fade due to aeration and can automatically add performance just when needed.

• For vehicles factory-equipped with twin-tubes, the monotube replacement shock absorber becomes a performance upgrade opportunity. It can increase a vehicles handling and stability without dramatically decreasing ride comfort.

Why do I need to replace worn shocks or struts?

• In a nutshell: To keep the vehicle’s stability within its designed capability. Stability means keeping the body as level as possible during bumps, turns, stops and turns: And, at the same time, keeping the tires on the pavement as much as possible during all driving conditions. The shock’s main job is to resist body & tire movement, but as shocks wear the vehicle becomes unstable; the steering feels less responsive, the body leans more and the tires grip less. Stopping ability can be reduced as much as 23% and the driver needs more skill to keep the vehicle on the intended path and from losing control on curves.

• Shocks cycle about 1500 times per mile driven. After 50,000 miles, that’s 75 million cycles. Because shocks use metal discs that flex with each movement, they become fatigued over time which causes the reduced performance, which is why replacement shocks and struts are suggested after 50,000 miles/80,000 kilometers.

What is the difference between shock absorbers and struts?

• The function is essentially the same, but the largest difference is the way they mount to the vehicle. The strut design acts an integral part of the suspension by replacing the upper control arm and acting as a pivot point for the steering.

• The shock design is used in addition to the suspension and steering components.

How do I know if a strut is rebuild-able?

• Struts cannot be refilled or rebuilt. However, some struts have a replaceable cartridge. These repairable struts can be identified by a large hexagonal shaped nut at the top of the strut body. Please remember that struts are usually gas charged and that replacement should only be performed by a qualified technician.

If I have a twin-tube shock can I switch to a monotube shock?

• Yes; for many vehicles that come factory-equipped with a twin-tube, KYB offers a monotube (Gas-a-Just & MonoMax) as a performance upgrade. This will increase the vehicle’s handling and stability beyond the factory design. Please use the KYB catalog to see if there is a monotube available for your specific vehicle.

Do I need to align my tires after I have my struts replaced?

• It depends on the vehicle design. A strut by design is also a component that supports the wheel & tire. Some models aren’t affected when the struts are replaced while others do change the wheel alignment. Strut removal and installation potentially changes the position of the tire alignment. Some struts have adjustment slots to perform the alignment with. All struts affect alignment in some way so it’s best to check the specific vehicle service manual and specifications.

Why are some Gas-a-Just shocks white and some are silver?

• KYB Gas-a-Just is sold all over the globe. By transitioning to one global color, the world becomes warehouse and improve product availability.

• Since 2007 all new Gas-a-Just part numbers were manufactured with the Silver Color.

• Beginning in January, 2011 as inventory of current white products is depleted, will be shipping the world-color Silver products.

• Part numbers remain the same; The product remains the same: Only the color is changing.

• Boxes containing the Silver Gas-a-Just can be identified easily: The part number is the same, but the label will be yellow and the 55XXXX global part number is added.

Are there any differences between the KYB shocks & struts manufactured in the U.S. vs. other countries (like Japan)?

• No. All KYB products are designed at the KYB world R&D offices and every KYB manufacturing plant then builds each product to the designed specifications. High volume part numbers are manufactured in more than one plant and in more than one country. Since KYB designs and builds own manufacturing equipment, can control and duplicate production specifications which ensures identical performance & quality at every manufacturing facility. Specific product performance is determined by part number, not by where it is manufactured. Product quality is a standard in every KYB part number, in every KYB manufacturing facility.