he idea of one partsmaker supplying a "corner module" that integrates suspension and braking components is relatively foreign in the United States.

A number of vehicle platforms in Europe and South America employ the concept with success, but the double wishbone-type suspensions in many U.S.-market vehicles make it difficult to install such large one-piece modules.

All that is about to change.

"We're working on eight programs right now in North America where people are trying to develop corner modules," says Clive Spackman, vice president of engineering at TRW Linkage & Suspension Systems. "It's definitely the way it's going."

Even though TRW, a giant in the suspension market, does not make brakes, Mr. Spackman estimates that 95% of the proposals his division is working on include wheel-end brake assemblies that would be supplied by another company.

The reason: It's easier, and less expensive, for a supplier to install brakes on the corner module than for vehicle assemblers to do it at the OEM level.

TRW's first front corner module in a North American vehicle appears in the Volkswagen Golf and the New Beetle, both produced in Mexico. TRW delivers three pieces for the vehicle - a crossmember and left and right corner strut modules, complete with brakes.

For model year 2001, TRW will supply similar corner modules - and "coordinate steering systems responsibility" - for an upcoming Chrysler Corp. Jeep platform through its joint venture with Krupp Hoesch Automotive. Whether the brakes will be integrated is a decision for Chrysler to make. Chrysler would choose the brake supplier, which would sell the components to TRW.

The company's first modular suspension was produced for the Rover Group in 1989, but it did not include brakes.

Automakers are tight-lipped about how much money can be saved by having integrated brakes in corner modules, but it must be sizable, based on OEM interest, Mr. Spackman says. In the Rover project, TRW helped its customer nearly double its labor productivity and decrease floor space by 60% in the suspension-assembly area.

Another supplier executive estimates that corner modules cost up to 20% less than conventionally assembled suspension systems.

Mr. Spackman discounts the notion that systems integrators such as TRW are able to do the same job as an OEM for less merely because they pay their employees less.

"It's not true," he says. "We are drawing our labor from the same pool as our customer, and we offer the same benefits. It's just a question of using better work practices. When you start from a greenfield, there's no history or downsizing issues."

Other suspension suppliers also are moving in the direction of corner modules, although the definition of a corner module varies among suppliers and automakers. In some cases, it consists of simply the hub and strut/spring units. Other module configurations include the brakes, suspension linkages and steering components.

Delphi Automotive Systems markets its Virtuoso package, which is basically an entire front end module, including the driveline and even the tire and wheel.

Arvin Industries and Tenneco Automotive, which compete head-to-head in suspension and exhaust systems, are both eyeing the brake market with hopes of supplying suspension and brake modules.

Tenneco was a front-runner to buy the brake and chassis business from ITT Automotive, but the deal fell through at the last minute and Continental AG of Germany ended up with the business, paying $1.9 billion in cash.

Arvin also was interested in ITT's brake business, but President and CEO V. William Hunt says his company could not justify the price.

Tenneco, ITT and Benteler Automotive Corp. have a joint venture to develop suspension modules and will announce a new contract for the operation in the fourth quarter, says Mark Frissora, senior vice president and general manager-North America for Tenneco Automotive.

It's not easy for a supplier to gain the confidence of its OEM customer to take over program management of a suspension module because it plays such a critical role in the safety and handling characteristics of a vehicle.

Mr. Frissora says the impact on OEM jobs also has slowed the migration toward supplier corner modules.

"It's been slow to happen because there is resistance internally (at OEMs) for it," Mr. Frissora says. "We're working with people who can see this and say, 'My god, I'm working myself out of a job.' But we're trying to partner with them."