 Although successful at overcoming the problems associated with the Gresley conjugated valve gear, the Holcroft variant used on No.822 suffered under a poor maintenance regime caused by the difficulty and expense of producing non-standard spare parts at Ashford works.The main problems associated with the Holcroft gear included inadequate lubrication of the moving parts and the whipping of the conjugation levers connecting the inside cylinder to the outside motion while running at high speeds, which caused uneven steam distribution to the cylinders.