Patent ID: 8191441

Claim:
A dual clutch transmission comprising: a transmission input member; a first output member; a first, second, third and fourth gear sets each having a first, second and third gears, wherein the first and second gears are each intermeshed with the third gear, the third gears of the first and second gearsets are rotatably fixed to the transmission input member, and the third gears of the third and fourth gearsets are rotatably fixed to the first output member; a first and second countershafts disposed parallel to the transmission input member, wherein the first gears of the third and fourth gear sets are each rotatably supported by and selectively engagable to the first countershaft and the second gears of the third and fourth gearsets are each rotatably supported by and selectively engagable to the second countershaft; a first and second drive tubes disposed parallel to the transmission input member, wherein the first gears of the first and second gear sets are each rotatably supported by and selectively engagable to the first drive tube, the second gears of the first and second gearsets are each rotatably supported by and selectively engagable to the second drive tube, the first drive tube is selectively engageable to the first countershaft, and the second drive tube is selectively engageable to the second countershaft; a first and a second multiple disc clutches each selectively connecting for common rotation one of the drive tubes with one of the countershafts; and four synchronizers each selectively engaging one of the first and second gears of the gear sets with at least one of the drive tubes and countershafts, and wherein one of the first and second clutches and two of the four synchronizers are concurrently engaged in order to establish one of at least eight forward speed ratios between the transmission input member and the first output shaft.