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Massey Ferguson 230, 235, 240, 245, 250 gasoline engine - Adjustment and repair

MF 230, 235, 240, 245, 250 Tractors Repair Operations

Cylinder head

Remove and reinstall - Drain Massey Ferguson 230, 235, 240, 245, 250 cooling system and remove hood. Shut off fuel, disconnect gage wire and remove fuel tank. Disconnect upper radiator hose from thermostat housing and wire from temperature gage sending unit. Disconnect air cleaner hose, fuel line, choke and throttle rod from carburetor, then remove the carburetor. Disconnect exhaust pipe on low exhaust models or remove muffier on vertical exhaust models. Remove intake and exhaust manifold, radiator brace, rocker arm cover and the rocker shaft assembly. Don't let push rods fall down into the cylinder block while removing the rocker shaft assembly. Lift all eight push rods out, remove spark plugs, then loosen cylinder head retaining screws. Remove the cylinder head screws and lift head off. Inspect cylinder for warpage, cracks or other damage. Original thickness of cylinder head is 86.52 mm (3.406 inches). Cylinder head may be machined up to 0.76 mm (0.030 inch) to obtain a nat gasket surface. Install by reversing removal procedure and observing the following: Cylinder head gasket is marked "BOTTOM" which should be toward block. New gasket should need no sealer; however, if difficulties with gasket sealing are encountered, coat both sides of gasket with heat resisting aluminum paint or appropriate sealer immediately before assembling. Tighten the cylinder head retaining cap screws. Tighten the screws evenly, increasing torque in 15-20 Nm (10-15 ft-lbs.) increments until the final torque of 95-102 Nm (70-75 ft-lbs.) is obtained. Be careful not to permit push rods to fall into block while installing rocker arm assembly. Make sure that caps are in position on all valve stems. Tighten rocker arm shaft support screws to 27-34 Nm (20-25 ft.-lbs.) torque. Adjust valve clearance cold to 0.33 mm (0.013 inch) for intake and 0.38 mm (0.015 inch) for exhaust. Tighten intake and exhaust manifold screws to 34-40 Nm (25-30 ft-lbs.) and spark plugs to 43-52 Nm (32-38 ft.-lbs.) torque. Retorque cylinder head retaining cap screws to 95-102 Nm (70-75 ft.-lbs.) and readjust valve clearance to "Hot" setting after engine has been started and reaches operating clearance.

Valve clearance adjustment - The recommended valve clearance with Massey Ferguson 230, 235, 240, 245, 250 engine cold is 0.33 mm (0.013 inch) for intake valves and 0.38 mm (0.015 inch) for exhaust valves. Recommended clearance with engine hot (normal operating temperature) is 0.28 mm (0.011 inch) for intake valves and 0.33 mm (0.013 inch) for exhaust valves. Valve clearance can be adjusted as follows: Remove timing plug from left side of cylinder block and turn crankshaft until top dead center timing mark is aligned with timing notch in housing. Check rocker arms for No. 1 and No. 4 cylinders. If rocker arms on No. 4 cylinder are tight, No. 1 cylinder is on compression stroke and valves indicated can be adjusted. If rocker arms on No. 1 cylinder are tight, No. 4 cylinder is on compression stroke and valves indicated can be adjusted. After adjusting the four valves indicated, rotate crankshaft one complete turn and adjust clearance of the remaining fourvalves.

Valves and seats - Intake valves seat directly in cylinder head and valve stems are equipped with neoprene oil seals. Positive type valve stem seal kit is available; however, valve guides must be machined to accept seal. Exhaust valves have renewable seat inserts and stems are equipped with positive type valve rotators. Replacement exhaust valve seat inserts are provided in 0.25 mm (0.010 inch) oversize only. When renewing the seal inserts, remachine cylinder head so insert counterbore measures 31.991-32.017 mm (1.2595-1.2605 inches) to provide recommended 0.08-0.13 mm (0.003-0.005 inch) interference fit. Intake valve face and seat angle is 30 degrees. Exhaust valves have a face angle of 44 and seat angle of 45 to provide the recommended 1 degree interference angle. Desired seat width is 1.6-2.4 mm (1116-3/32 inch) for all valves. Seats can be narrowed using 15 and 75 degrees stones.

Valve guides - The presized intake and exhaust valve guides are interchangeable. Inside diameter of new guides is 8.019-8.057 mm. Inner bore of new guides has a fine, spiral groove or rifling which gives guide an unfinished appearance upon inspection, but guide must not be reamed. To renew the guides, press old guides downward out of cylinder head using a piloted mandrel. Press new guide in from the top until distance measured from rocker arm cover gasket surface to top of guide is 2.38 mm (13/32 inch). Valve stem diameters and clearance limits in guides are as follows: Valve Stem Diameter-Intake 7.978-7.998 mm (0.3141-0.3149 in.) / Exhaust - 7 935-7.955 mm (0.3124-0.3132 in.). Clearance-Intake 0.021-0.079 mm (0.0008-0.0031 in.) / Exhaust 0.064-0.122 mm (0.0025-0.0048 in.).

Cam followers - The mushroom type cam followers (tappets) operate directly in machined bores of the cylinder block and are available only in standard size of 14.262-14.275 mm (0.5615-0.5620 inch). Clearance in bore should be 0.013-0.046 mm (0.0005-0.0018 inch). The cam followers can be removed from below after removing camshaft. Cam followers should be reinstalled in their original positions if being reused. Cam followers should be renewed if camshaft is renewed.

Rocker arms - Rocker arm bushings are not renewable. Renew rocker arms and/or shafl if clearance between shaft and bushing is not within limits of 0.013-0.046 mm (0.0005-0.0018 inch). Rocker shaft is positioned by locating pin in shaft which fits in a notch in front face of the third support bracket. Begin assembly by installing pin in notch of bracket. Install one rocker arm stamped "7R", spring rocker arm stamped, another bracket, another rocker arm stamped "7R", short spring, washer and cotter pin to the short end of shaft. Install remaining parts to longer end of shaft. Rocker arms are alike and stamped "7R". Rocker arms are alike and stamped. Springs are identical as are support brackets. Short spring, washer and cotler key are used at each end.

Timing gears cover

Remove and reinstall - First separate the front system from the MF 230, 235, 240, 245, 250 engine as follows: Drain cooling system, remove front grille panels and disconnect battery cables. Remove fuel tank cap, radiator cap and hood. Disconnect headlight wires and pull wiring free. Disconnect both radiator hoses, radiator brace and, on Massey Ferguson 230, 235, 240, 245, 250 tractors so equipped, hydraulic oil lines and front mounted pump. Support tractor at front of transmission. Position wedge blocks between front axle and axle support. Support the front end assembly at front and rear. Disconnect drag links and radius rods at rear of models so equipped. On models with drag links, attach drag links to axle so wheels will be straight ahead and will not turn. On models with power steering, disconnect lines, remove the power steering pump and cover all hydraulic steering openings. On all MF 230, 235, 240, 245, 250 models, unbolt the front assembly and carefully roll away from tractor. Remove the fan belt and crankshaft pulley. Detach the spring and rod from the governor control lever. Unbolt the timing gear cover from engine block and oil pan, then carefully pull cover forward off dowels. The crankshaft front oil seal can be renewed at this time. Press seal out, do not pry, to prevent damage to cover. Press new seal into position from inside with lip toward inside. The inside edge of seal should be flush with rear of seal bore in cover. Install cover by reversing removal procedure. Be sure that driving lug on governor cup is at 6 oclock position before installing cover. Trim the gasket between cylinder block and cover until ends are flush with cylinder block. Sealing between the timing gear cover and oil pan is more easily accomplished by installing oil pan with new gasket after cover is installed. Tighten the timing gear cover to engine block screws to 34-40 Nm torque, and the oil pan to timing gear cover screws to 16-22 Nm 02-16 torque.

Timing gears - Timing gears can be renewed after removing timing gear cover. Withdraw governor race and shaft assembly from camshaft. Remove nul retaining camshaft gear to camshaft and lift off the governor ball driver assembly. Remove liming gears using suitable puller. Be careful not to damage governor shaft bore in camshaft when pulling camshaft gear. Recommended backlash between crankshaft and camshaft gears is 0.03-0.05 mm (0.001-0.002 inch). Gears are available in standard size, undersizes and oversizes. Gears are marked "S" (standard), "U" (undersize) or "O" (oversize) and the number "1" or "2" denotmg 0.001-0.002 inch oversize or undersize. Correct backlash between crankshaft and oil pump gears is 0.089·0.107 mm (0.0035-0.0042 inch). During installation, mesh the single punch marked tooth on crankshaft gear with the double punch marked tooth space on camshaft gear. Heating camshaft gear in oil or in an oven to approximately 149C (300F) will facilitate gear installation. Remove oil pan and support camshaft in a forward position while gear is being installed to prevent loosening and leakage of camshaft rear plug. Tighten the camshaft gear retaining nut to a torque of 95-108 Nm.

Camshaft - Remove the camshaft, first remove camshaft timing gear. Remove fuel tank, rocker arm cover, rocker arms and shaft assembly and push rods. Remove the ignition distributor and oil pan. Block up or support the cam followers. Remove the screws securing camshaft thrust plate to engme block and withdraw camshaft from front of engine. All camshaft journals ride directly in machined bores in the cylinder block. Normal diametral clearance is 0.064-0.114 mm (0.0025-0.0045 inch). Renew camshaft and/or cylinder block if clearance exceeds 0.18 mm (0.007 inch). Camshaft journal diameter is 45.92-45.95 mm (1.808-1.809 inches) for front journal, 44.34-44.36 mm (1.7455-1.7465 inches) for center journal and 42.75-42.77 mm (1.683-1.684 inches) for rear journal. Camshaft end play is controlled by thrust plate and is normally within a range of 0.076-0.178 mm. Thickness of thrust plate when new is 3.735-3.785 mm (0.147-0.149 inch).

Rod and piston units

Connecting rod and piston units are removed from above after removing cylinder head and oil pan. Correlation marks on rod and cap should be installed facing camshaft side of Massey Ferguson 230, 235, 240, 245, 250 engine. Replacement rods are not marked but should be stamped with cylinder number before installation, on side of rod opposite the oil spray hole. Piston skirts are notched at lower edge; notch is to be installed to front of engine when unit is reassembled. Tighten the connecting rod cap screws to a torque of 54-61 Nm (40-45 ft-lbs.).

Pistons, sleeves and rings - Pistons are available in standard size only, and are available only in a kit which includes piston, pin, rings and sleeve for one cylinder. Piston is cam ground. If piston and/or sleeve are scored, if piston ring grooves or pin bore are worn or damaged, or if cylinder wall taper exceeds 0.20 mm (0.008 inch), renew piston and sleeve assembly. Piston ring kits are available separately. Kits are marked for correct piston ring installation. Correct installation of rings. Recommended piston ring end gap is 0.25-0.50 mm (0.010-0.020 inch) for all rings. Recommended side clearance in ring groove is 0.09-0.13 mm (0.0035-0.0050 inch) for top ring; 0.09-0.14 mm (0.0035-0.0055 inch) for second and third compression rings. Renew piston and sleeve assembly if side clearance of top ring exceeds 0.19 mm (0.0075 inch), or 0.20 mm (0.008 inch) for second or third compression rings. Install the piston rings in grooves. The piston rings are for use in new sleeves, and rings are for service in worn sleeves. To install rings for new sleeves observe the following: The top ring is chrome plated, taper faced and may have inside diameter beveled. The side of ring marked by dot or by bevel cut away should be toward top of piston. The second and third compression rings are taper faced and should be installed with side marked by dot toward top.

Install oil ring expander in groove first, then install rails with gaps 50 mm (2 inches) from the gap in expander. Gap in one rail should be to left, other to right of gap in expander. Install rings for use in used cylinder sleeves, observe the following. The chrome plated top ring is taper faced. Install top ring with dot or beveled inside diameter toward top of piston. The second compression ring should be installed with beveled inside diameter or dot toward top. The third compression ring should have expander behind ring and the relief cut into outside diameter of ring should be down. The expander for the bottom oil control ring should be installed first, followed by the two rails. One rail should have end tap 50 mm (2 inches) to left of expander ends, the other rail should have end gap 50 mm (2 inches) to right. The cylinder sleeves have notched reliefs at bottom for connecting rod clearance. The relief notches should be at right angles to crankshaft centerline. Use a suitable puller to remove the wet type cylinder sleeves. Clean all surfaces of cylinder block which contact sleeve or sleeve seals. Install sleeve into cylinder block bore before installing any seal rings to check for sleeve standout. Select the necessary thickness of shims to provide 0.03-0.10 mm (0.001-0.004 inch) standout. Measure distance using a straightedge and feeler gage and be sure that sleeve is fully seated without nicks, burrs or foreign material preventing complete installation. Excessive or insufficient standout will both cause water leakage. After sleeve standout has been checked, install sealing rings at bottom of sleeves. Make sure that seal rings are not twisted, then lubricate seals with petroleum jelly. Press sleeves into place being careful not to damage or lose shims. Notches should be perpendicular to crankshaft.

Piston pins - The full floating piston pins are retained in piston bosses by snap rings. Piston pins are available in standard size and 0.08 and 0.13 mm (0.003-0.005 inch) oversizes. Recommended clearance for piston pin in both the connecting rod and piston is 0.005.0.015 mm (0.0002-0.0006 inch). Standard piston pin diameter is 21.821-21.826 mm (0.8591-0.8593 inch). Hone new bushings to 21.831-21.836 mm (0.8595·0.8597 inch) after installation in connecting rod. Connecting rods and bearings - Connecting rod bearings are of the precision type, renewable from below after removing oil pan. When installing new bearing shells, make sure that the projection engages the milled slot in rod and cap and that rod and cap correlation marks are in register. Replacement rods are not marked and should be stamped with cylinder number on side away from oil spray hole. Correlation marks should be on camshaft side of block when rods installed. Bearings are available in undersizes of 0.05, 0.25 and 0.50 mm (0.002, 0.010 and 0.020 inch) as well as standard.

Crankshaft and bearings

The crankshaft is supported in three precision insert type main bearings. The rear main bearing cap contains sealing strips on each side of cap in addition to rear seal. Bearing inserts are available in undersizes of 0.05, 0.25 and 0.50 mm (0.002,0.010 and 0.020 inch) as well as standard size. Normal crankshaft end play of 0.10-0.20 mm (0.004-0.008 inch) is controlled by the flanged center main bearing inserts. To remove crankshaft, it is necessary to remove Massey Ferguson 230, 235, 240, 245, 250 engine, clutch, flywheel, rear oil seal, timing gear cover, oil pan, oil pump main bearing and connecting rod caps. Renew or regrind crankshaft if either main journals or crankpins are worn more than 0.025 mm (0.001 inch), are tapered more than 0.025 mm (0.001 inch), or are out-of-round more than 0.038 mm (0.0015 inch). Renew or straighten crankshaft if runout (total indicator reading) exceeds 0.076 mm (0.003 inch), checked at center main journal.

Crankshaft rear oil seal - The crankshaft rear oil seal is contained in a one-piece retainer and serviced only as an assembly. To renew the seal, first separate engine from transmission case and remove the flywheel. Remove the oil pan and the two cap screws securing rear sea retainer to main bearing cap; remove the three remaining cap screws and lift off the oil seal and retainer unit. Apply a light coating of oil to seal lip, and apply gasket sealer to mounting gasket. Position seal retainer with the two threaded holes down. Reinstall cap screws and tighten evenly to a torque of 11-14 Nm (8-10 ft.-lbs). Complete the assembly by reversing the disassembly procedure. Flywheel - Remove the flywheel, separate MF 230, 235, 240, 245, 250 engine from transmission case and remove the clutch. The starter ring gear can be renewed after removing the flywheel. To install a new ring gear, heat gear evenly to approximately 232C (405F) and install on flywheel with beveled edge of teeth facing front of engine. One flywheel mounting stud is off center so flywheel can only be installed in the correct position. Tighten the flywheel retaining screws to a torque of 95-102 Nm (70-75 ft.-lbs).