Applications Pultruded Driveshafts. Volume has continued to grow well in excess of light truck growth rates during the 1988-92 period. Despite the success of the technical and production aspects of the part, economics limit the growth of this application. In the GMC truck potential of 500,000 units annually, the composite eliminates a multi-piece driveline, thus reducing assembly time, inventory cost, maintenance, and part number complexity. Other benefits are the elimination of warranty associated with center bearings, noise and vibration dampening in the passenger compartment, corrosion- resistance, and custom design of driveshaft performance based on model use and power train system.
Production begins with a seamless aluminum tube.
It is the composite formulation which is responsible for eliminating the center bearings. The part is engineered with an isolation barrier between the tube, and graphite fiber eliminates electrolytic galvanic corrosion. Production rate and economics for the Spicer unit are not available. In 1985, competitors estimated that full production would demand one unit, or five to six feet per minute. But the company has no plans to introduce the advanced composite driveshaft in production models.