A funnel assembly comprising: a main body/funnel having a first open end and a guide tube; the guide tube having a second open end and the first open end is communicating with the second open end; a first sleeve including a first axial part and a second axial part; the first axial part having a first opening end while the second axial part having a second opening end; wherein the second axial part is formed by extension and bending of the first axial part; a second sleeve including a third axial part and a fourth axial part; the third axial part having a first opening end and the fourth axial part having a second opening end; wherein the third axial part is extended and bent to form the fourth axial part; an extension tube including a first opening and a second opening, wherein the first opening and the second opening are communicating with each other; a cover including a threaded part and a base arranged with a mounting hole; wherein the threaded part is used for connection to a oil fill hole; wherein the second open end of the main body/funnel is mounted into the first axial part of the first sleeve; characterize in that a plurality of stopping slots is disposed around an inner surface wall of the second opening end with a certain interval between two adjacent stopping slots; a step portion arranged with a projecting block is set between the third axial part and the fourth axial part; a plurality of axial ribs (11a, 11b) is arranged around a surface of the extension tube at a certain interval; and a plurality of concave parts disposed around an inner surface of the mounting hole of the cover at a certain interval; wherein one of the ribs on the first opening of the extension tube is aligned with one of the stopping slots of the second axial part and then the extension tube and the first sleeve are connected to and positioned with each other at a plurality of radial angles; wherein one of the ribs on the second opening of the extension tube is aligned with one of the positioning slots on the third axial part of the second sleeve and then the extension tube and the second sleeve are connected; and wherein the projecting block of the fourth axial part of the second sleeve is aligned with one of the concave parts of the cover and the second sleeve and the cover are connected to and positioned with each other at a plurality of radial angles. a main body/funnel having a first open end and a guide tube; the guide tube having a second open end and the first open end is communicating with the second open end; a first sleeve including a first axial part and a second axial part; the first axial part having a first opening end while the second axial part having a second opening end; wherein the second axial part is formed by extension and bending of the first axial part; a second sleeve including a third axial part and a fourth axial part; the third axial part having a first opening end and the fourth axial part having a second opening end; wherein the third axial part is extended and bent to form the fourth axial part; an extension tube including a first opening and a second opening, wherein the first opening and the second opening are communicating with each other; a cover including a threaded part and a base arranged with a mounting hole; wherein the threaded part is used for connection to a oil fill hole; wherein the second open end of the main body/funnel is mounted into the first axial part of the first sleeve; characterize in that a plurality of stopping slots is disposed around an inner surface wall of the second opening end with a certain interval between two adjacent stopping slots; a step portion arranged with a projecting block is set between the third axial part and the fourth axial part; a plurality of axial ribs (11a, 11b) is arranged around a surface of the extension tube at a certain interval; and a plurality of concave parts disposed around an inner surface of the mounting hole of the cover at a certain interval; wherein one of the ribs on the first opening of the extension tube is aligned with one of the stopping slots of the second axial part and then the extension tube and the first sleeve are connected to and positioned with each other at a plurality of radial angles; wherein one of the ribs on the second opening of the extension tube is aligned with one of the positioning slots on the third axial part of the second sleeve and then the extension tube and the second sleeve are connected; and wherein the projecting block of the fourth axial part of the second sleeve is aligned with one of the concave parts of the cover and the second sleeve and the cover are connected to and positioned with each other at a plurality of radial angles.