Pistons, Rods and Cylinder Block CYLINDER BORE 0.50 mm (0.020 in.) Oversize Bore Inspection Standard . . . . . . . . . . . . . . . 66.50 - 66.53 mm . . . . . . . . . . . . . . . . . . . . . . . (2.619 -2.620 in.) Wear Limit. . . . . . . . . . . 66.70 mm (2.626 in.) Measure cylinder bore diameter at three positions; top, middle and bottom. At these three positions, measure in both directions; along crankshaft center line and direction of crankshaft rotation. Cylinder Bore I.D. - 3TNA72 (3009): Standard Size Bore 1 NOTE: If engine has had a previous major overhaul, oversize pistons and rings may have been installed. Standard . . . . . . . . . . . . . . . 72.00 - 72.03 mm . . . . . . . . . . .
. . . . . . . . . . . .(2.835 - 2.836 in.) Wear Limit . . . . . . . . . . 72.20 mm (2.843 in.) Clearance . . . . . . . . . . . . . 0.28 mm (0.011 in.) 0.25 mm (0.010 in.) Oversize Bore Standard . . . . . . . . . . . . . . . 72.25 - 72.28 mm . . . . . . . . . . . . . . . . . . . . . . .(2.845 - 2.846 in.) Wear Limit. . . . . . . . . . . 72.45 mm (2.852 in.) 0.50 mm (0.020 in.) Oversize Bore Standard . . . . . . . . . . . . . . . 72.50 - 72.53 mm . . . . . . . . . . . . . . . . . . . . . . .(2.855 - 2.856 in.) Wear Limit. . . . . . . . . . . 72.70 mm (2.862 in.) If cylinder bore exceeds wear limit, replace cylinder block or have cylinder rebored.
(See Reboring procedure.) If cylinder is rebored, oversize pistons and rings must be installed. Pistons and rings are available in 0.25 mm (0.010 in.) and 0.50 mm (0.020 in.) oversize. If clearance (cylinder bore I.D. minus piston O.D.) exceeds specification, replace cylinder block, piston or both; or rebore cylinder and install oversize piston and rings. Cylinder Bore I.D. - 3TN66: Standard Size Bore Standard . . . . . . . . . . . . . . . 66.00 - 66.03 mm . . . . . . . . . . . . . . . . . . . . . . .(2.599 - 2.600 in.) Wear Limit . . . . . . . . . . 66.20 mm (2.606 in.) Clearance . . . . . . . . . . . . . 0.25 mm (0.010 in.) Deglazing IMPORTANT:
If cylinder bores are to be deglazed with crankshaft installed in engine, put clean shop towels over crankshaft to protect journal and bearing surfaces from any abrasives. 0.25 mm (0.010 in.) Oversize Bore Standard . . . . . . . . . . . . . . . 66.25 - 66.28 mm . . . . . . . . . . . . . . . . . . . . . . .(2.609 - 2.610 in.) Wear Limit. . . . . . . . . . . 66.45 mm (2.616 in.) 1. Deglaze cylinder bores using a flex-hone with 180 grit stones. 1-40 4/7/95 AllTractorManuals.com Top Position Middle Position Bottom Position n of aft Rotation of aft e M8 Directio Cranksh n of aft Rotation Direction Cranksh Centerlin of aft e M8 2053A