Synchronizer

A method for forming a transmission synchronizer friction surface comprising:

• forming a woven substrate fabric formed of an appropriate precursor fiber suitable for forming carbon fiber;
• oxidizing the substrate fabric by subjecting the substrate to a first elevated temperature in an atmosphere including oxygen;
• carbonizing the substrate fabric by subjecting the substrate to a second elevated temperature in a non-oxidizing atmosphere;
• after carbonizing, densifying the substrate fabric by chemical vapor deposition so as to deposit pyrolytic carbon on the substrate fabric;
• after densifying, burnishing the substrate fabric;
• after burnishing, applying a thermoset adhesive to a bonding side of the substrate fabric;
• cutting a piece of the substrate fabric of a size suited for use on a synchronizer element;
• after applying the adhesive and cutting the piece of the substrate fabric, heating and pressing the piece of fabric against a conical surface of the synchronizer element with the bonding side disposed against the conical surface, said method characterized by:
• spinning a yearn of chopped substrate fibers;
• weaving the yarn into the woven substrate fabric;
• increasing densification by extending a period of time of chemical vapor deposition to achieve a weight in an unburnished condition of at least 16 ounces per square yard for a thickness range of approximately 40 to 50 mils (0.040 to 0.050 inches);
• burnishing both sides of the substrate fabric to remove a predetermined amount of material from each side;
• and
• pressing the substrate fabric against the conical surface under a high pressure of at least 2000 psi to achieve the desired bonding of the substrate fabric to the conical surface.