83 and the lips 81 of upper supports 79 lower compression springs 89 are positioned on bolts 85 below lips 81 and maintained in position by a nut 91 the upper compression springs 87 are compressed to exert a slight upper pressure on the gearbox 71 to remove stresses of the weight of the gearbox from bearings 23 and the power source furthermore during operation as the gearbox 71 rotates opposing upper and lower compressions springs 87 and 89 co operate to return the cross support 83 and thus the gearbox 71 to a level position gearboxes known in the art are typically provided with a male splined connector for connecting to the input and output shafts not shown accordingly as shown in fig9 axial rod 20 is provided with a female splined connector adapted to receive the male splined connector of gearbox 71 as shown in fig8 a connection arm 93 is attached to the top of the gearbox 71 at one end thereof and secured to a bracket 95 mounted on the processing tub 1 the connection arm prevents the gearbox 71 from pulling away from the processing tub 1 thereby disconnecting from the axial rod 20 it.