Over time they were displaced from most passenger work by new build DMUs such as the "Sprinter" units, though they still found work in the summer and on secondary services from time to time through the 1990s as traffic demand required. This saw use both on the North Wales Coast and, most remarkably, Cardiff - Rhymney local services through to 2006. In Scotland after being displaced from the West Highland and far north routes, 37/4s were used on two diagrams on the Inverness - Edinburgh route for several years as well as being used to Kyle of Lochalsh in the summer and on Inverness - Aberdeen services. The final daily work in Scotland was the Fort William "Caledonian Sleeper", this ending in June 2006.