Tough Truck, Rough Ride?

Looking for a solid profit centre that delivers excellent customer satisfaction? One answer to that age-old search may be sitting behind the white-lettered tires of the hottest vehicle market segment on the continent: light truck/SUV. They’ve been hot enough, long enough to represent a significant part of the ride control replacement market, and many designs respond very well to upgrades, even with stock wheel and tire combinations.

What do customers expect in this segment? Chuck Gonwa, product manger for KYB America LLC, says “It really depends on who’s driving the vehicles. In the U.S., over 50 percent of vehicles are SUV’s and women buy over 50 percent of those. Women will take a ride and expect it to be more like a passenger car, and that’s the way the manufacturers are going, tuning the suspension to be on the soft side. It targets their main market. Men, on the other hand, depending on how they use the truck, deliver mixed results. Some think it’s fine and handles well, while others use it more for heavy duty usage, either at work or for towing and want to beef up the suspension. Some figure out that the vehicle isn’t what they expected on the drive home from the dealer and change shocks right away.”

Change shocks on a new vehicle? It’s something that can be suggested during a visit for regular maintenance. Relative to the cost of a modern SUV, the demographic that antes up forty to fifty thousand dollars for a new vehicle may be willing to invest in ride/handling improvements. “For normal driving O.E shocks and struts are designed to perform at certain levels”, declares Carlo Falcigno, national product and training manager for ArvinMeritor Light Vehicle Aftermarket (Gabriel), adding “this performance may be inadequate for your customer. Aftermarket product can offer innovative solutions to the need for different control levels. Some product is velocity sensitive which, simply put, means the faster the piston moves the more resistance develops. Addition valves in the piston are utilized to enhance this resistance to movement relation. The bottom line is that some aftermarket designs can offer the customer a softer ride without sacrificing control.”

With OEM’s forced into a “one size fits all” approach to vehicle ride control it stands to reason that a notable proportion of SUV/light truck owners aren’t getting what they perceive as the optimal ride/handling balance. “The vehicles tend to be too soft,” says KYB’s Gonwa, “unless it’s a high-end sport suspension vehicle. GM, for example, on the Trailblazer, Envoy and Escalade, are switching over to monotube shocks, because they want a sport ride and control. Lower end, less expensive vehicles are using lower priced twin-tube shocks with softer suspensions from the factory.” The implication is clear: offer consumers some of the ride/handling benefits of a high-end SUV with a shock change.

Inside the SUV/light truck shock, designs generally break down into two types: twin tube and mono tube. Chuck Gonwa describes the difference: “Twin tube is a telescopic strut. It’s a tube inside a tube. The inner cylinder is where all the work is done; that’s the pressure or working cylinder, where the hydraulic dampening action takes place. Twin tube shocks allow the gas and oil to mix together, and under heavy usage, it will foam internally, and you’ll develop shock fade.”

Upgrades are a nice business to cultivate, but replacement of worn units will always be the driving force behind the aftermarket ride control segment. Inspection is key, and just as importantly, a standardized inspection procedure should be followed. Gabriel’s Carlo Falcigno is responsible for training at ArvinMeritor Light Vehicle Aftermarket:

“When checking a vehicle for worn or damaged suspension parts, it’s always best to follow a consistent inspection procedure. In this way the chance of missing a problem is reduced.” Falcigno recommends the following procedure for vehicle inspection:

Monroe, which has promoted ride control from a safety perspective through their “Safety Triangle” campaign this year, invited SSGM Editor Jim Anderton to observe head -to-head tests using identical vehicles. Compared to worn OE shocks, the aftermarket units (in this case Monroe Sensa-Trac shocks) demonstrated a major improvement in braking and handling. “Our studies of vehicle stopping distance and emergency handling precision show that our premium shocks enhance overall driving safety when compared with worn OE-replacement units”, states Mark Christiaanse, director of marketing-ride control for Tenneco Automotive (Monroe). “For example, vehicles equipped with four OE-replacement shocks, one of which was 50-percent degraded, needed an average of nearly 6 percent greater distance to brake from 60 miles per hour to a complete stop when compared to vehicles equipped with Monroe premium products.” For many consumers resistant to the ride/handling proposition, safety can be the right button to push.

1. Vehicle mileage considerations: Although mileage is not an accurate way to determine shock and strut failure, it can be an indicator for the need to have more frequent inspections. Generally, shocks and struts should be inspected every 18,000 to 25,000 kilometers. Under more severe conditions or as the vehicle gets older with higher mileage it may be a good idea to increase the frequency of inspections. Remember that shocks and struts move a minimum of 10 million times every 35 thousand kilometers.

2. Check the tires: The tires play an important role in vehicle control and safety. Worn tread or improper inflation pressure can have a negative effect on the vehicle’s performance. For example, when shocks or struts begin to wear and lose some control, the tires may begin to show signs of a wear condition known as cupping. Tire tread cupping will appear as high and low spots, which are fairly regular, around the tire. Other tire wear patterns can also indicate improper vehicle alignment or loose suspension components.

3. Test-drive the vehicle: The best way to diagnose a shock, strut or many suspension problems is to test-drive the vehicle. When coming to a complete stop does the vehicle continue to rock from front to back? When accelerating does the vehicle’s nose move up excessively? During cornering does the vehicle lean to a point where control may be negatively affected? These are some of the conditions present with worn or failed shocks and struts that may go unnoticed because of the driver’s familiarity with the slow deterioration. Small day-to-day differences tend to go unnoticed.

4. Ride height and alignment: With proper tire inflation pressure confirmed, the vehicle ride height should be checked. The vehicle will have a recommended ride height range. Improper ride height, generally caused by weak springs, can affect the vehicle’s alignment. Proper alignment is an important factor related to vehicle control, handling, and component wear.

5. Shock and strut inspection: During inspection several items should be checked. Oil originating from the shock or strut and found on the side of the product is a good indication that the product will need to be replaced. The shock and strut assembly should also be checked for severe dents, broken brackets, rusted or pitted piston rods, damaged compression bumpers, torn protective boots, damage or binding in the strut mount or strut mount bearing, rusted springs, coil clash, (indicated by shiny points on the spring where the coils are contacting each other during compression), and general mounting hardware condition.

6. Other steering and suspension system components: Check for damaged or dried out bushings, damaged or worn tie rods and tie rod ends, ball joints, and steering system components. SSGM

Do Worn Shocks Really Matter?

Monroe, which has promoted ride control from a safety perspective through their “Safety Triangle” campaign this year, invited SSGM Editor Jim Anderton to observe head -to-head tests using identical vehicles. Compared to worn OE shocks, the aftermarket units (in this case Monroe Sensa-Trac shocks) demonstrated a major impro
vement in braking and handling. “Our studies of vehicle stopping distance and emergency handling precision show that our premium shocks enhance overall driving safety when compared with worn OE-replacement units”, states Mark Christiaanse, director of marketing-ride control for Tenneco Automotive (Monroe). “For example, vehicles equipped with four OE-replacement shocks, one of which was 50-percent degraded, needed an average of nearly 6 percent greater distance to brake from 60 miles per hour to a complete stop when compared to vehicles equipped with Monroe premium products.” For many consumers resistant to the ride/handling proposition, safety can be the right button to push.