An assembly for a gas turbine engine comprising: a housing enclosing a first shaft extending from a first spline at a first end to a second spline or a key-drive socket at a second end; a second shaft extending from a third end accessible through an exterior wall of the housing to a third spline complementary to the second spline or a key-drive complimentary to the key-drive socket at a fourth end; a thrust plate extending from and rotatable with the second shaft; a spring circumscribing the second shaft and between the thrust plate and the housing; wherein the spring biases the second shaft towards the exterior wall of the housing; the assembly further comprising: a seal cap affixed within and enclosing a bore of the housing at the exterior of the housing and circumscribing the third end of the second shaft; wherein the bore of the housing extends between the exterior wall of the housing and a housing lip; a static seal disposed within a first groove extending circumferentially about an outer diameter of the seal cap, the static seal engaging the bore of the housing; and a lip seal disposed within a second groove extending circumferentially about an inner diameter of the seal cap, the lip seal engaging the second shaft; a radial drive shaft rotationally coupled, in use, to a rotor of the gas turbine engine and rotationally coupled to the first shaft at the first end, and/or an accessory gearbox rotationally coupled in use, to a shaft coupled to the first shaft at a gearing, the accessory gearbox rotationally coupled to one or more of a fuel pump, a lubricating oil pump, a hydraulic pump, an air turbine starter, a generator, and an engine starter; and a duplex bearing (32A, 32B) or bushing affixed within the bore relative to and abutting the seal cap, laterally supporting the second shaft; wherein the thrust plate is disposed between the duplex bearing or bushing and the lip of the housing wherein the spring is positioned in the bore between the thrust plate and the housing lip. a housing enclosing a first shaft extending from a first spline at a first end to a second spline or a key-drive socket at a second end; a second shaft extending from a third end accessible through an exterior wall of the housing to a third spline complementary to the second spline or a key-drive complimentary to the key-drive socket at a fourth end; a thrust plate extending from and rotatable with the second shaft; a spring circumscribing the second shaft and between the thrust plate and the housing; wherein the spring biases the second shaft towards the exterior wall of the housing; the assembly further comprising: a seal cap affixed within and enclosing a bore of the housing at the exterior of the housing and circumscribing the third end of the second shaft; wherein the bore of the housing extends between the exterior wall of the housing and a housing lip; a static seal disposed within a first groove extending circumferentially about an outer diameter of the seal cap, the static seal engaging the bore of the housing; and a lip seal disposed within a second groove extending circumferentially about an inner diameter of the seal cap, the lip seal engaging the second shaft; a radial drive shaft rotationally coupled, in use, to a rotor of the gas turbine engine and rotationally coupled to the first shaft at the first end, and/or an accessory gearbox rotationally coupled in use, to a shaft coupled to the first shaft at a gearing, the accessory gearbox rotationally coupled to one or more of a fuel pump, a lubricating oil pump, a hydraulic pump, an air turbine starter, a generator, and an engine starter; and a duplex bearing (32A, 32B) or bushing affixed within the bore relative to and abutting the seal cap, laterally supporting the second shaft; wherein the thrust plate is disposed between the duplex bearing or bushing and the lip of the housing wherein the spring is positioned in the bore between the thrust plate and the housing lip. a seal cap affixed within and enclosing a bore of the housing at the exterior of the housing and circumscribing the third end of the second shaft; wherein the bore of the housing extends between the exterior wall of the housing and a housing lip; a static seal disposed within a first groove extending circumferentially about an outer diameter of the seal cap, the static seal engaging the bore of the housing; and a lip seal disposed within a second groove extending circumferentially about an inner diameter of the seal cap, the lip seal engaging the second shaft; a radial drive shaft rotationally coupled, in use, to a rotor of the gas turbine engine and rotationally coupled to the first shaft at the first end, and/or an accessory gearbox rotationally coupled in use, to a shaft coupled to the first shaft at a gearing, the accessory gearbox rotationally coupled to one or more of a fuel pump, a lubricating oil pump, a hydraulic pump, an air turbine starter, a generator, and an engine starter; and a duplex bearing (32A, 32B) or bushing affixed within the bore relative to and abutting the seal cap, laterally supporting the second shaft; wherein the thrust plate is disposed between the duplex bearing or bushing and the lip of the housing wherein the spring is positioned in the bore between the thrust plate and the housing lip.