Tackling the multi-link challenge

by | Feb 20, 2018 | 0 comments

As suspension systems have become more sophisticated, the challenge for shop owners to ensure that repairs are conducted effectively and profitably has become more acute than ever.

The demands on suspensions to provide responsive and safe handling are pushed to the limit designs by continual reductions in weight; the need to ensure that that suspension service maintains that performance is also ramped up.

At the more practical level, the wear in various multi-link suspension components can cause noises that are difficult to diagnose. Worn suspension parts can also cause uneven tire wear and create alignment problems that consumers will not likely understand, but can push of your customer service and repair efficiency to make right and to do so profitably.

“Cars are made differently than before and contain more pieces to change,” says Dany Girard, product manager for Levis, Que.-based Transit Auto Parts. “It’s not rare to see a car with six or more control arms!”

Girard says stabilizer/sway bar link kits have become one the most popular movers, further evidence that the multi-link suspension is having more than it’s fair share of failures.

And yet with the exploding part requirements, quality continues to be an imperative, if tougher to determine.

“Quality never goes out of style,” says John Thody, founder of XRF Chassis Parts. “There are a hundred online programs that list the quality ranked repair people in your area for everything from plumbing, window repair and auto repair. I have not seen one that recommends places that do a poor job.”

Thody makes the point that no respectable independent garage sets out to execute a poor quality repair; sometimes however, there isn’t an accurate appreciation of how significant a drop in quality might be when looking for a budget alternative.

“Our market may be a little different for the ordinary producer because of our strength in the light-medium duty truck fleets,” says Thody. “Because our parts are specifically designed for fleet requirements, our big movers are Ram and Ford Super Duty pickup truck ball joints.  These trucks go every day and downtime cost a lot of money.”

The online world is full of examples of chassis parts that failed well before their expected time—one post had a ball-joint with failed rubber components after only 5,000 km–and likely looked worse than the part it replaced.

In contrast, quality aftermarket parts are full of enhancements that can set them above the OE construction, addressing both longevity and easing installation.

Mevotech X Factor stabilizer links, for example, incorporate durable upper and lower metal bearings that surround the ball joint stud and ball, and include grease fittings not part of the OE design, so techs can flush out old grease and contaminants during inspection and maintenance routines.

In another example, Moog’s Problem Solver sway bar link kits, utilize polyurethane bushings for durability, but also include features such as a barrel nut for easing thread engagement and nesting washers to keep bushings centred during installation.

The latter in particular can help maintain repair efficiency.

Transit’s Girard says too that it’s not just about longevity of parts; the number of interdependent parts in a multi-link suspension means that the dimensions of any part must be very precise in order to allow for accurate installation, alignment, and safety when one adds in the active safety systems that are becoming more prevalent.

Even small inaccuracies in dimensions, both static and when torqued, can affect the ability to execute an efficient post-repair alignment. Variances of this sort can make it difficult to achieve alignment specifications, can extend the time to do so, and, in the case of shops outsourcing their alignments, may also increase hard costs.

Even so, it’s not always the part itself that can cause problems. A recent pair of recalls by Ford—one in April 2017, and expanded one in December 2017, serves as a case in point:

“Affecting some 24,000 vehicles, the safety recall affecting 2011-17 Ford Explorer and 2013-2017 Ford Police Interceptor Utility vehicles was restricted to Alberta, Saskatchewan and Manitoba. According to the recall, affected vehicles operated in Alberta, Saskatchewan and Manitoba can experience unique mud accumulation in the rear frame pocket where the rear suspension toe link attaches to the frame, impeding articulation of the toe link, which may result in toe link fracture. A vehicle with a fractured toe link may experience noise and unusual vehicle handling characteristics, increasing the risk of a crash. Ford is aware of three accidents, one with injuries, associated with this issue.”

Even when such extreme circumstances are not at play, it is important for shops to ensure they are not leaving themselves open to early failures or other quality related issues.

Few things will sap the profit and efficiency from your bays as fast as a warranty repair.

As experienced shop owners know, quality parts don’t cost, they save.

“They save money and their clientele too!” says Girard. “It’s never a good thing to change parts during the warranty lifetime. Repair businesses make money on two different things: labour and parts. When they change parts under warranty they don’t make money on parts, and they can lose the trust of their client.”


Advanced Driver Assist Systems drive alignment imperatives

Although the need for proper alignment to ensure safe driving characteristics and longevity of other components, especially tires, is not new the proliferation of Advanced Driver Assist Systems (ADAS) has added a whole new element.

Driver assist systems rely heavily on sensors, especially the steering angle sensor, to function properly. Just as suspension wear that can create an “off centre” steering wheel and cause increased tire wear, it can also driver assist systems to malfunction.

For example, during normal driving, Electronic Stability Control systems work in the background and continuously monitors steering and vehicle direction. It compares the driver’s intended direction (determined through the measured steering wheel angle) to the vehicle’s actual direction (determined through measured lateral acceleration, vehicle rotation (yaw), and individual road wheel speeds).

It is easy to see how a mismatch between the direction being travelled and the steering angle can compromise the performance of the system.

Steering Angle Sensor Reset

ADAS systems can be affected by mechanical alignment adjustments. This has led many manufacturers to require electronic resets for these systems, after a wheel alignment is performed, after part replacement, windshield replacement, a number of other changes. The reset procedure may require the vehicle to be drive.

Shop owners should ensure that they are equipped to perform these reset procedures—or the subcontractor they use is—and that they are accurately charging for these procedures, which can amount to as much as eight hours of labour in some cases.



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