April 2019

bearings are susceptible to wear and tear due to harsh road conditions and adverse weather, which is why, to follow best practice, it is advisable to replace them every 50,000 miles or whenever the shock absorber or coil spring is changed. Worn suspension components can increase braking distance by 15% and vibration by as much as 25%, as well as making the vehicle much less responsive.” These components have evolved over time: “Since their introduction, top strut mounts and bearings have gone through significant transformation from ‘generation 0’, featuring a simple steel bearing in a steel beading, to the current ‘generation 2.5’ solution, which uses a steel bearing with integral upper spring and shock absorber support, made from sophisticated, premium quality plastic composites. Prudent policy As with any suspension work, these components should be replaced in pairs so the vehicle’s opposite side should be changed too. Jon observes: “This is a prudent policy not only because it is more economical than owners making two visits to the workshop, more importantly it avoids inequality in the vehicle’s steering geometry. “Common causes of top strut mount failure include corrosion from water, sand and salt ingress; fractures as a result of poor road surfaces or accident damage; and false brinelling, a.k.a localised surface corrosion, caused by micro-vibrations during vehicle movement. “All these failures can result in increased noise, including clunking, knocking, grinding or creaking, particularly at low speeds when moving the steering from lock to lock on poor road surfaces, as well as increased torque on the steering wheel, making spotting the failure relatively straightforward. In addition, a faulty top strut mount or bearing can have a big effect on the rest of the vehicle’s suspension components and will increase the chance of their subsequent failure.On some vehicles however, it can be the case that the top strut mount fails prematurely at low mileage and there are several instances, particularly with a number of Fiat applications where this is the case. Examples include the the Fiorino/Qubo and their Citroën Nemo/Peugeot Bipper/Bipper Tepee cousins, Doblo, Grande Punto and Ducato. Some of these failures are linked to poor design or specification and have forced the OE manufacturers to re-design and upgrade them due to water and grit penetrating the bearing, causing rust and corrosion and leading to seizure. Another common cause of water ingress comes as a result of jet washing under the wheel arches, where water can get into the bearings, which again can lead to failure.” Jon adds: “Freezing conditions will also be a problem if there is water penetration, as this will also cause damage to the bearings.” Technology Technological change can be incremental and slow within the arena of steering and suspension as with all things, but progress is taking place. MOOG has developed a new Hybrid Core bearing technology. Massi Milani, Executive Director, Marketing, EMEA Aftermarket, Tenneco/Federal- Mogul Motorparts EMEA explains the innovation going on: “Through the use of carbon fibre reinforcement, Hybrid Core technology significantly increases the bearing durability of MOOG’s control arms, ball joints, tie rod ends and axial rods. Durability and safety are further improved through the use of induction hardening on the components’ studs. Induction hardening is a heat treatment process that provides a fivefold increase to a part’s surface hardness and can double the strength of studs. “The new design also reduces the gradual increase in radial deflection that components can experience during their service-life, commonly and more simply known as ‘play’. Reducing this abnormal increase in deflection means that the precise steering feel and controlled suspension movement is maintained throughout the use of the component.” Massi continues: “We understand the importance of steering and suspension components in the safety and comfort of a vehicle – two of the most significant and reassuring factors for drivers. That is why we developed Hybrid Core Technology and continue to invest in technologies and processes that provide our customers with advanced and reliable parts. “Hybrid Core technology is being introduced on a majority of MOOG’s parts, alongside other product innovations that improve durability and comfort: zinc coating and a new variety of synthetic grease. MOOG’s ball joints and link stabilisers now feature a zinc coating, making them exceptionally corrosion resistant and further improving durability. Simultaneously, a zinc-flake coating is now applied to all MOOG’s accessories, helping to increase resistance to corrosive road conditions. Additionally, the engineers at MOOG have selected a new synthetic grease that enables extremely smooth actuation while also providing workshops with increased ease of installation.” According to Massi, using quality parts provides an afterglow for the business: “If reliable parts are fitted to a customer’s vehicle, it is beneficial for the technician’s reputation and provides the customer with a level of reassurance, especially considering the three-year guarantee on all MOOG parts.” There is training available too: “Workshop personnel can also benefit from the recent launch of Garage Gurus, a technical training and support platform that has been designed to keep techs informed and at the top of their game.” Availability is widening also: “While the brand’s products have been available in Europe since 2001, it has recently announced the opening of a factory in Barcelona, Spain that will produce a majority of MOOG’s parts. All these components will feature the new technologies. The new factory will also result in improved part availability throughout Europe.” 34 AFTERMARKET APRIL 2019 STEERING AND SUSPENSION www.aftermarketonline.net It is vital that steering and suspension systems are checked throughly during maintenance and servicing ”