Press Releases

Tenneco Automotive's RANCHO® Brand Offers the Next Generation of Premium Off-Road Shocks with RANCHO RSX

November 2, 1999

LAS VEGAS, Nov. 2, 1999 - Designing an off-road shock absorber with premium components means nothing without a corresponding increase in durability, longevity and superior off-road performance. The RANCHO RSX shock provides all of these benefits and more thanks to innovative Reflex Technology Valving.

Reflex Technology Valving
The heart of the RANCHO RSX shock absorber is its valving system that reacts when a vehicle encounters a bump or when the shock is compressed. The harder a vehicle is driven over uneven surfaces the more active the valve becomes - opening the instant a large bump is encountered and closing immediately after the impact has been absorbed, returning the shock to its original calibration. Reflex damping provides a measured response to changing surface conditions while providing superior off-road performance.

"We asked our engineers to develop a premium on- and off-road shock absorber that further secures our market leadership," said Terry Heffelfinger, engineering manager for new product development, Tenneco Automotive North American aftermarket. "Our engineers delivered on that challenge with the next generation of shocks that continues the RANCHO tradition of superior off-road performance and a product that's tough, durable and reliable."

Research and Development
Ten thousand man-hours were devoted to the two-year RSX development cycle and more than 500 prototypes were designed, constructed and extensively tested to assure long life and reliability. In-house testing involved both laboratory and field analyses. RANCHO engineers impact tested the new valving at 2.5 meters/sec. for thousands of cycles to simulate the extremes of off-road racing, while high-speed bi-frequency tests over the course of one million cycles validated product durability.

In tests conducted at the Ohio Transportation Research Center, Marysville, Ohio, a 1997 Jeep Grand Cherokee outfitted with RANCHO RSX shocks showed a 12 percent decrease in vehicle body roll rate during a J-turn maneuvers performed at 50 mph when compared with a Grand Cherokee with original equipment shock absorbers. The vehicle also showed an 18 percent reduction in pitch rate during ABS brake testing from 50 to 0 mph when compared with a Cherokee outfitted with original equipment shock absorbers.

Premium Components
All RANCHO RSX shocks include premium components, including hardened chrome piston rods with a micro-finished surface for smooth operation and positive sealing; a Fluon™ banded piston made with Teflon® and glass reinforced fibers to reduce sliding fiction, increased product life and improve sealing; and nitrogen gas charging to 150 psi to reduce aeration and heat fade.

Silica Technology Rubber Shock Mounts
The RANCHO RSX shock is fitted with Reinforced Silica Compound (RSC) rubber shock mounts. RSC shock mounts, the result of years of research and development by Tenneco Automotive's Clevite elastomer engineers, use proprietary advanced silica technology. These compounds are made of a natural elastomer that is modified and reinforced with silica providing improved durability and longevity. This unique compound cushions like rubber, but limits bushing noise and elongation sometimes associated with urethane type products. In addition, RSC shock mounts have undergone real-world testing on Scott Douglas' Championship Off-Road Racing Ford F-150.

RSC shock mounts are molded in the color red for an aesthetic match with RANCHO dust boots and product graphics. RSC mounts are true-fit, requiring no assembly and are designed to plug into specific applications. For trouble free installation, RSC mounts are designed to fit original mounting points.

Reduced Noise, Vibration and Harshness
"Tenneco Automotive's ability to custom mix materials, manufacture premium components and test products to extremes have culminated in a RANCHO RSX shock that maintains vehicle control during hard cornering and braking without transmitting unwanted noise, vibration and ride harshness to the passenger compartment," said Heffelfinger.

Nearly 100 SKUs are now available, including part numbers for each RANCHO's suspension systems.

To find the nearest RANCHO Outfit Center call 1-800/GO-RANCHO. For technical information call 1-800/574-6257 or visit the RANCHO Web site at

Tenneco Automotive is one of the world's largest producers and marketers of ride control and emission control products and systems, which are sold under the Monroe® and Walker® global brand names. Among its products are Monroe® Sensa-Trac® shocks and struts, Rancho® shock absorbers, Walker® Quiet-Flow™ mufflers and DynoMax™ performance exhaust products, and Monroe® Clevite™ vibration control components.