Towards the end of his life Cokayne was preoccupied by questions of inheritance and the consequent family disputes. He was possibly aware of his impending death when in the Spring of 1438 he levied a fine of lands to compel the tenants of his manors of Calton, Staffordshire, and Ballidon, Derbyshire, to recognise the rights of Isabel, his second wife, as joint landholder.Collections for a History of Staffordshire, volume 11, p. 244-5. He had conditionally leased Ballidon to John and Robert Taylor, two local men, the previous year,Jeays (ed). Descriptive Catalogue of Derbyshire Charters, p. 28, no. 217. probably in preparation for this legal stratagem. Similarly Calton was leased to Richard Bingham and Richard Bromley, who agreed to recognise John and Isabel as joint holders of the estate.Calendar of Close Rolls, 1435–1441, p. 212. Bingham and John Manchester were similarly used as lessees to levy fines on other Derbyshire and Warwickshire properties. The aim seems to have been to speed Isabel's succession on Cokayne's death but to secure the estates in tail male, thus avoiding losses due to his heir's minority.
