This unusual wheelbox could be a solution in some installations.

40 tooth gear wheel. 

Taper 7.1mm - 9.5mm  over 6mm

Mounts through a 16mm hole with two flats.

M8 thread.

Tapered rubber bush, fibre washer, nut and rubber sealing cap included.

Weight 250gms.

TALL TAPER-MOUNT SPINDLE WIPER WHEELBOX #WBOX4