double shaft automatic transmission a multi range transmission comprising the under drive transmission 300a and the auxiliary transmission 300b through a pair of tapered roller bearings 106 installed under adjusted prepressure with a spring member 105 interposed and a nut 16b fastened at one end and an output shaft 17 of the transmission 300 is supported an output gear 17a of the output shaft 17 is meshed with a drive gear wheel 501 of the transfer 400 a cylindrical sun gear shaft 18 is rotatably supported through a bushing between the flange like projection 16a on the second intermediate transmitting shaft 16 and the inner member 159a a cylindrical outer member 19 is rotatably supported through a bushing on the outside of the inner member 159a an outside of a left end of the sun gear shaft 18 is engaged by spline with an inside of a right end of the outer member 19 in the under drive mechanism chamber 130a at the right side thereof a first hydraulic servo drum 20 opened at its left portion is rotatably engaged with the front support 153 and an annular piston 21 is fitted between inner and outer circumferential walls thereof to form a hydraulic servo c 2 of the clutch c2 a return spring 22 is mounted to the inner wall side of the servo drum while the clutch c2 is mounted to the inside of the outer wall thereof on the left side of.