Arrangement for fitting an exhaust cleaning unit in an exhaust passage

An arrangement for fitting an exhaust cleaning unit in an exhaust passage for exhaust from an engine, the exhaust passage passing through an aperture in a part of the engine, the arrangement comprising:

• a gasket fitted around the exhaust cleaning unit and configured, located and operable to serve as a seal between the exhaust cleaning unit and an internal wall surface of the exhaust passage;
• and
• an annular resilient component which is fitted around the exhaust cleaning unit at a distance from the gasket, the annular resilient component having a first contact portion configured, located, and operable to come into contact with a wall surface of the exhaust cleaning unit and a second annular contact portion configured, located and operable to come into contact with a wall surface of the exhaust passage when the exhaust cleaning unit is in a fitted state in the exhaust passage, and the annular resilient component is configured and operable for keeping the exhaust cleaning unit in a centered position in the exhaust passage with a spring force of the annular resilient component.