tender for overhauling and reconditioning of wornout elecon make helical gear box- model sbn 355, ratio- 22.4:1 work involves draining the contaminated oil, opening the top cover, dismantling the internals from the gear box, dismantling the bearings, sleeves, spacer rings from the input, 1st intermediate wheel, pinion gear outside shaft, checking the trueness of all the input, intermediate wheel & pinion shaft, metal filling by welding with suitable welding rod in the input pinion shaft bearing seating area, input shaft bore area, top casing and bottom casing of gear box, the input shaft and 1st intermediate wheel and gears in position after fixing the bearings, spacer rings and fixing the output shaft and thread cleaning of all the bolt fixing tap holes for fixing the top & bottom casing and all the bearings and covers and setting the gear black lash, fixing the top cover of the gear box, tightness checking the bolt & nuts and filling the gear box oil up to required level, including the cost of spacer rings bearings 30317j - 2 nos, 30324a - 2 nos., 32034x - 2nos, oil seals etc., and devolution of the bearing scrap to central stores nctps-i.