Keeping up with crossovers

Chances are you’ve got customers coming to your shop who’ve crossed over — from a passenger car, that is. The crossover utility vehicle (CUV) craze is growing — General Motors of Canada Ltd., for example, saw its sales of crossover vehicles jump 72.5 per cent in 2006 — as more and more drivers go for these cool vehicles with the functionality of a full-size SUV, but built with a chassis and drivetrain that’s similar to a car.

From the new GMC Acadia to the Ford Edge, to the Acura MDX and the Mitsubishi Outlander, the list of import and domestic models of these car-based SUVs keeps expanding.

“These vehicles are really trucks in disguise,” says John Thody, marketing manager for Marysville, Mich.-based XRF Autoparts. “From the steering and suspension point of view this presents some real issues.”

Thody says technicians have to remember the greater weight, higher center of gravity, fore-and-aft weight distribution, and the fact that the front wheels are performing both drive and brake functions on these heavier-than-a-car-but-lighter-than-a-truck vehicles. There’s also the rack-and-pinion steering of crossover SUVs.

“Front brakes need to be monitored more closely, as they do the great percentage of braking. One can expect greater disc pad wear,” he says.

The first reason is with a crossover there’s simply more weight to stop and that’s harder on the braking system. Then add in the higher center of gravity that allows greater energy flow forward during braking.

“Front wheels both drive and brake,” Thody adds. “While the brakes are trying to stop the vehicle, the engine and transmission are trying to drive it. Brake proportioning valves must be in good working order, not only to manage fore and aft braking, but also to assist in vehicle tracking.”

So when a crossover is in for a brake job, make sure you’re installing either OE parts designed for the task, or high-quality aftermarket parts. Federal-Mogul this year, for example, introduced its new Wagner Edge brake pad system. It’s based on an exclusive laser-shaped friction technology that gets the most from interaction between rotors, pads and calipers.

“This revolutionary approach helps to eliminate pad vibration — and resulting noise — at its source while ensuring the precise transfer of caliper force where it’s needed most,” Federal-Mogul said in a June 7 press release about Wagner Edge.

Federal-Mogul also markets Wagner TheromQuiet brake pads and shoes that it says offer superior stopping power and enhanced durability. ThermoQuiet covers 99 per cent of all passenger vehicles, SUVs and light trucks, the company notes in the Product Finder area of its web site.

Watch for early wear

Crossover vehicles are prone to premature brake and suspension wear that’s usually chalked up to normal wear and tear, but it may likely be caused by former car drivers not used to how different crossovers handle. Driving a crossover like it’s a lighter vehicle puts a lot of load on the brakes, suspension and steering components.

Making sure customers’ CUVs are in for regular preventive maintenance is extremely important. “Brakes, steering and suspension need to be watched closely, particularly if the owner has moved from a car to a CUV and is unfamiliar with a heavier vehicle,” notes XRF’s John Thody. “Front wheel bearings and seals should be monitored, as the front brakes will generate significant heat.”

Early wear and rotor problems caused by excessive heat are some of the most common problems you need to look out for on these vehicles.

When it comes to servicing a front-wheel drive (FWD) crossover versus a model with all-wheel drive (AWD), the thing that techs need to be most aware of says Thody, is brake, tire and tie-rod wear, which are greater on FWD models because there’s more stress on the front end than with an AWD crossover.

Steering and suspension are the other big issue with crossovers. The greater weight, weight distribution and higher center of gravity means greater ride-height change during braking and acceleration, notes Thody. “Ride height change means toe change and toe change means tire wear and stress on the tie-rod ends.” So technicians need to be looking at tie-rods, too when crossovers are in for regular maintenance.

Alignment also becomes a crucial issue with crossovers. “It becomes important to make ride height estimates based on the typical load the vehicle will be carrying — will it be one passenger or four; golf clubs or bathing suits?”

There are plenty of aftermarket products to help you ensure proper, good ride control on crossovers. For a 2006 Chevrolet Equinox, for example, Tenneco recommends its Monroe Reflex truck shock absorbers for improved stability with reduced harshness. For good control on the Equinox, Monroe Sensa-Trac struts are recommended.

The company makes it easy to find the right ride control solutions for crossovers with its online product catalogue (www.tenneco.com/frames/monroe.html) — select the make and model from drop-down menus, and the recommended part and its number are displayed.

Some of the newest ride control technology is the Kinetic Suspension System, also from Tenneco. The Kinetic Dynamic Suspension System (KDSS) was invented and developed by Kinetic Pty Ltd., a small Australian research and development company. One vehicle using this new suspension technology is the redesigned Toyota Landcruiser. KDSS offers reduced articulation stiffness, increased roll stiffness, more ride comfort and decoupled roll and bounce damping all in a passive system. None of the features and benefits of KDSS are available in conventional suspension, Tenneco notes on its web site (www.tenneco.com/frames/kinetic.html).

Suspension problems to watch out for when you’re servicing crossovers could include front suspension noises caused by insufficient clamping force of the lower arm to the sub-frame, a front damper spring coil hitting the end of the spring, or faulty front dampers.

Generally, crossovers are popular with many drivers because of their roominess, cargo capacity, and smooth ride and handling.

“Consumers feel that the vehicle is less likely to roll over and the longer wheelbase gives a good ride,” notes Thody.

And for technicians, they’re relatively easy to service. “Crossovers have a little more room to work than a car, and a little less than a truck. Most are a MacPherson Strut design and will be about the same as a Chrysler mini-van to work on,” says Thody.

Chassis Development

How have crossovers affected chassis development?

“From what I’ve seen, not too much,” says Thody. “It looks like a CUV body has been plunked on a proven platform with a few modifications. Remember, these are first-generation vehicles and we can expect to see some changes in subsequent model years as everyone learns more about how they’ll be used.”

Still, there are some developments. The Mitsubishi Outlander, for example, features what’s known as a Reinforced Safety Evolution chassis with rigid unibody construction. This chassis allows use of MacPherson Struts for the Mitsubishi’s independent front suspension and a multi-link suspension on the rear end.

And look for aluminum being used in a big way now. American Axle & Manufacturing (AAM), a tier one supplier, makes its crossover vehicle I-Ride chassis module totally out of aluminum.

The module consists of a cast aluminum monocque rear module structure, a PowerLite aluminum rear independent axle and the new AAM PowerLite aluminum power transfer unit (PTU).

“AAM engineered the module to be bolted into the vehicle with minor vehicle modifications,” the company says.

And Lotus Cars has developed its Versatile Vehicle Architecture (VVA). The VVA chassis is made with aluminum high-pressure die-castings, stampings and extrusions. Aluminum components are joined with self-pierci
ng rivets and advanced adhesives. Lotus says the key to VVA is the frame’s “four corner nodes.” These complex cast-aluminum nodes are designed to be identical in each vehicle model that would be developed with VVA. The nodes can connect with structural members that are different sizes and angles — this allows for VVA to be used for a wide range of vehicle body shapes, sizes and weights, including crossovers.

Crossovers down the road

If crossovers aren’t your favourite vehicle to service, get used to them because you’re going to be seeing more and more down the road.

In the 2007 model year in Canada, there were about eight all-new or redesigned crossovers. Overall, there were more than 30 models offered from virtually every domestic and import manufacturer.

For drivers, they’re cool. For technicians, they’re mostly just another vehicle. XRF’s Thody doesn’t anticipate too much that technicians should be watching for in terms of crossover vehicle servicing developments as the crossover craze with drivers. “These are back-to-basics vehicles,” he says.

Resource List

Tenneco www.tenneco.com

Federal-Mogul www.federal-mogul.com

XRF Autoparts www.xrfautoparts.com