A gasket retainer that is absent sharp corners, has apertures of reasonable dimensional tolerance, and may be conveniently made by a variety of manufacturing processes. The retainer is made from thin flat springy material that readily returns to form after slight bending. Representative gasket capturing apertures are of smoothly non-convex outline with major dimension sufficiently large to allow passage of a ring shaped gasket turned on edge and minor dimension sufficiently small to engage, on approximately opposite circular segments that each engage along less than one third of a gasket circumference, a cavity or groove on the outside diameter periphery of the gasket turned flat parallel to the retainer material sheet. Fasteners may be retained by similar apertures.

Systems are provided for a coupling element. In one example, the coupling element comprises a rotating element configured to rotate an aftertreatment device relative to a section of an exhaust passage in response to a force greater than a threshold force.

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.

An outboard motor that significantly reduces or prevents discoloration around an exhaust hole includes an engine, a drive shaft, a propeller shaft, a housing, a discharge passage, and non-metal covers. The housing includes a discharge outlet to discharge an exhaust gas of the engine and the cooling water of the engine. The discharge passage guides the exhaust gas and the cooling water from the engine toward the discharge outlet. The covers are detachably attached to the housing so as to cover the discharge outlet and include at least one exhaust opening.

An exhaust gas purification device includes an upstream cylinder, a downstream cylinder, and a purifying cylinder. The upstream cylinder, the purifying cylinder, and the downstream cylinder each have at an end thereof a flange portion having a flat connecting surface. Each flange portion of one of the upstream and downstream flange portions of the purifying cylinder, and the flange portions of the upstream cylinder and the downstream cylinder includes an engagement pin having an engagement recess portion. Each flange portion of the other includes a pin hole and an engagement groove. The engagement recess portion is fitted into and engaged with the engagement groove.

An internal combustion engine exhaust system includes an exhaust gas treatment unit carried at a carrier. The carrier has a receiving opening (20), receiving the treatment unit, with a first sealing surface (28) enclosing the opening. The exhaust gas treatment unit has a second sealing surface (42), enclosing a treatment unit longitudinal axis, located opposite the first sealing surface. The exhaust gas treatment unit has a third sealing surface (44), enclosing the treatment unit longitudinal axis. A closing element (48), fixable with the exhaust gas treatment unit to the carrier, has a fourth sealing surface (50), located opposite the third sealing surface. A first sealing element (52) is arranged between the first sealing surface and the second sealing surface. A second sealing element (54) is arranged between the third sealing surface and the fourth sealing surface. The first sealing element and the second sealing element are of identical configuration.

A metal gasket containing a metal plate having an opening portion and having a seal bead having a bent cross-sectional shape formed along the opening portion in order to suppress a variation in the height of the seal bead due to a tensile stress generated in the outer periphery of the seal bead in the molding of the seal bead is provided with a lightening hole extending along the outer periphery of the seal bead, in which the distance between the lightening hole and the seal bead is constant.

A manifold gasket includes two or more metal plates laminated together to form the manifold gasket, a plurality of bores formed in the metal plates, a plurality of annular seal portions, each surrounding each of the plurality of bores to seal therearound, a plurality of bolt holes disposed at an outer periphery of each of the plurality of annular seal portions so that fastening bolts are inserted therethrough, and a partition protector having a thermal deformation coping portion, located in the two or more metal plates between two of the bores. The thermal deformation coping portion includes offset slits in each metal plate such that none of the slits are aligned in a lamination direction of the thermal deformation coping portion, and such that the slits prevent damage to the manifold gasket due to temperature fluctuations by accommodating thermal expansion or contraction of the manifold gasket.

Systems are provided for a coupling element. In one example, the coupling element comprises a rotating element configured to rotate an aftertreatment device relative to a section of an exhaust passage in response to a force greater than a threshold force.