It was decided in 1983 that the 70 Class railcars would be replaced, No. 78 had already been withdrawn in 1978 after just 10 years of service after being bombed by the IRA. No. 76 was withdrawn in 1984 and the remaining units followed in 1985–1986. The last set in service was a five-car set operated by power cars no. 75 and 77. Both were withdrawn on Tuesday 1 April 1986. For the new units, and after heavy refurbishment, engines, generators and traction motors were recovered as the 70s were withdrawn for re-use in the new 450 class. After withdrawal, it was discovered that the power cars contained blue asbestos, so they were sent to Crosshill quarry, Crumlin, along with other NIR stock and even some CIÉ stock for disposal. They were put into a flooded part of the quarry, since water dampens asbestos, meaning that no loose fibers could escape from their structures. Most of the under frames were kept for use as flatbeds.