Abstract: An exhaust system of an internal combustion engine includes a slip joint with a female section having an opening with an inner diameter, a male section having an outer diameter smaller than the inner diameter of the opening of the female section, the male section being at least partially received in the female section, a wear sleeve disposed between the female section and the male section, and at least one seal contacting the wear sleeve and at least one of the female section and the male section, to seal the slip joint.

Abstract: A fastener and a method for reducing stress failure in a fastening joint of an internal combustion engine component is disclosed. The threaded fastener may be a bolt or a stud secured to an engine block. The fastener has a threaded tip portion with a radius and a distal end. The threaded tip portion is inserted into a threaded hole to define a threaded interface. In one embodiment, the load carrying capability is increased by progressively reducing the radius of at least a part of the threaded tip portion. In another embodiment, the load carrying capability is increased by an axially extending hole at the distal end of the threaded tip portion, the hole having a progressively reduced diameter.