from entering into the body member 52 the shaft member 54 includes a shaft 72 and a sprocket 74 the sprocket 74 rotatably couples the shaft 72 with the drive train 18 the sprocket 74 is retained on the shaft 14 by lock washer 76 and lock nut 78 a seal 80 seals the shaft 72 with the upper plate 15 of the single deck 14 the seal 80 prevents lubricants from escaping from the cavity 17 within the single deck 14 a retaining cap 73 is positioned in the axial bore 68 at the end of the second portion 70 of the body member 52 the cap 73 positions bearings 62 and 64 within the body member 52 an oil seal 75 may be positioned in the retaining cap 73 the oil seal 75 is positioned about the periphery of shaft 72 to lubricate the shaft 72 as it rotates a second cap 77 retains the oil seal 75 within the retaining cap 73 the shaft 72 has two ends one end 83 includes a threaded member 82 for securing the chuck mechanism 56 onto the shaft 72 the other end 84 includes internal threads for enabling a coolant fixture 86 to be coupled with the shaft 72 the shaft 72 includes an axial bore 87 passing through the shaft 72 the axial bore 87 includes an enlarged portion 88 towards the end 83 of the shaft 72 a collet insert 90 is positioned in the enlarged portion 88 of the axial bore 86 a collet.