Australia’s market leader in ride performance products, Monroe, advises that replacing only a single shock or strut could lead to adverse vehicle performance and premature tyre, steering and suspension component wear.
Like other vehicle systems and components, shock absorbers, which stroke an average of 2,800 cycles per kilometre, are subject to significant wear over time. When replacing one worn or damaged shock absorber, it is vitally important to also replace its counterpart on the other side of the vehicle in order to maintain consistent performance and to prevent premature wear.
Because a new shock absorber has experienced no internal wear, pairing it with an old unit could create uneven damping characteristics, and cause the newer shock to wear out much faster than expected, because the replaced unit will need to work harder to compensate for the wear of the old shock absorber.
Replacing only a single worn or damaged shock absorber can create adverse effects on vehicle performance characteristics, increasing both suspension component and tyre wear. It is critical that automotive technicians always replace both shock absorbers on a single axle to ensure a safer and much more comfortable ride for their customers.
Worn and damaged shock absorbers have a significant impact on driver comfort and safety, causing vehicles to excessively bounce and sway, adversely affecting steering response along with causing increased stopping distances.
Monroe recommends that automotive technicians check shock absorbers for wear or damage with every vehicle service, and when carrying out other repairs such as brake or tyre replacements.
When conducting vehicle inspections, automotive technicians should look for common signs of worn and damaged shocks and struts, which include damaged steering and suspension ball joints, poor steering response, fluid leaks from the shock or strut body, cupped or uneven tyre wear, and excessive vehicle bounce. When performing road tests, technicians should also look out for any leaning or swaying during lane changes.
Another important part of checking a vehicle’s suspension is the condition of the strut mounts when replacing shock absorber struts.
Strut mounts are subjected to heavy vibration during their lifespan and as like any rubber to metal bonded parts, they are susceptible to wear over time. Worn strut mounts or bearing plates can adversely affect vehicle handling and safety as they are an important component of the suspension system. Worn strut mounts and bearing plates can cause noise, steering bindingor even be the cause of steering pull. In the worst cases, worn strut mounts can allow the upper end of the strut to change position which directly affects wheel alignment angles. If such wear is not detected properly at the time of replacing shock absorber struts, it almost always results in customer returns, premature tyre wear and suspension component fatigue.
To increase the lifespan of any vehicle strut, replacing a worn strut mount and bearing plate is essential. These integral suspension components work together with the strut to isolate road vibrations and to provide smooth and safe steering response. To best service Australian automotive repairers, Monroe provides complete Strut-Mate Mounting Kits which are easy to install.
In most cases with strut suspensions, the upper strut mount replaces the upper control arm and bushings, upper ball joint and control arm pivot shaft, making this component the pivot point of a vehicle’s suspension. Once replaced, the flexibility of the mount allows the strut angle to change to follow the travel of the lower ball joint. The rubber portion of the mount is designed to reduce vibrations and transmitted road noises. The bearing plate built into these mounts serves as the upper pivot point and forms the steering axis, so when the front wheels are steered, the entire strut is able to pivot from the lower ball joint to the upper strut mount. The upper strut mount may also carry the load and transfer that load to the spring and strut housing.
To check for worn or defective strut mounts, automotive technicians should first do a road test, checking for unusual noise, pulling or steering binding. Then with the car parked in the workshop and on the ground, rotate the steering from stop to stop while listening for noise or the effects of binding, which are indicative of a defective bearing.
The rubber portions of the strut mount also need to be checked for cracks or separation from the steel before raising the vehicle. Also before activating the hoist, the technician needs to take note of the position of the strut piston rod. Then once the vehicle is raised note any change in the position of the strut mount assembly. A slight downward movement is normal, but any side to side movement more than likely indicates a worn strut mount.
The next step, once the vehicle is raised, is to grip the coil spring as close to the upper strut mount as possible, then push in and out on the strut while watching for movement of the upper end of the piston rod. There should be no free movement, if there is movement, the strut mount needs to be replaced. The inspection is completed by checking the steering pivot to ensure smooth and free rotation, while also checking all rubber components for breaking away from the metal, visual signs of cracking and general wear.
Monroe Strut-Mate Mounting Kits feature original equipment style bearings, SAE grade nuts and bolts, superior rubber to steel bonding and plated steel for longer wear. These premium quality replacement strut mounting kits have been manufactured to meet or exceed original equipment specifications.
Visit the Monroe Australia website – www.monroe.com.au for more information on feel free to contact their technical experts by calling 1800 088 205.
