John Deere Valve Adjustment Service Manual PDF - Engine Repair Guide (EN)

- - ------------ Engine Repair Cylinder Head, Valves and Camshaft 20-05-1 Group 05 CYLINDER HEAD, VALVES, AND CAMSHAFT PRELIMINARY VALVE CHECKS Camshaft Failures Scored camshaft lobes due to inadequate lubrica- tion Excessive end play due to thrust plate wear Broken or warped camshaft due to improper timing During disassembly, inspect the valve train for the following malfunctions and causes.

Sticking Valves Carbon deposits on valve stem Worn valve guides Warped valve stems Cocked or broken valve springs Worn or distorted valve seats Insufficient lubrication Checking Valve Clearance Four-Cylinder Engine Warped, Worn, or Distorted Valve Guides Lack of lubrication Cylinder head distortion Excessive heat Unevenly tightened cylinder head cap screws Distorted Cylinder Head and Cylinder Head Gasket Leakage Improperly tightened cylinder head cap screws Faulty gasket installation Incorrect gasket material Excessive oil pressure Improper cylinder liner height above cylinder block Worn or Broken Valve Seats Misaligned valves Distorted cylinder head Carbon deposits on seats due to incomplete com- bustion Valve spring tension too weak Excessive heat Improper valve clearance Improper valve timing Burned, Pitted, Worn, or Broken Valves Worn or distorted valve seats Worn valve guides Insufficient cooling Insufficient lubrication Cocked or broken valve springs Preignition Improper engine operation Improper valve train timing Faulty valve rotators Warped or distorted valve stems "Stretched" valves due to excessive spring tension Warped cylinder head Bent push rods Carbon build-up on valve seats Rocker arm failure Fig.

1-Sening "TOC" 1. Rotate engine to position No. 1 piston at TDC of its compression stroke. 2. Turn flywheel until timing mark on flywheel lines up with mark on housing (Fig. 1). TM-1106 (Jan-79) Litho in U.S.A. Engines - 400 Series

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20-05-2 Cylinder Head, Valves, and Camshaft Engine Repair Six Cylinder Engine Checking Valve Clearance-Continued Four Cylinder Engine ....... , 4 E I 3 I E 2 E I 1 I E II T2284?N VALVE CLEARANCE SPECIFICATION Intake and Exhaust Valves 0.018 In. (0.46 mm) R 27478NJ lj Fig. 2-Four-Cylinder Valve Clearance Adjustment Fig. 3-Setting "TOC" 3. Adjust valve clearance on No. 1 and 3 exhaust valves and No. 1 and 2 intake valves. 1. Use JOE-81 Engine Rotation Tool Set (A, Fig. 3) to position No. 1 piston at TOC of its compression stroke. 2. Turn flywheel untiltiming pin engagestiming hole in flywheel and both valves on No. 1 cylinder are in the up position (rocker arms loose). 4.

Rotateflywheel 360 degrees until No.4 piston is at TOC of its compression stroke. 5. Adjust valve clearance on No. 2 and 4 exhaust valves and No. 3 and 4 intake valves to the specifica- tion listed above. OF ENGINE- 432 1 E I lEE I I E NO. I TDC COMPRESSIONSTROKE 6 5 4 3 2 1 EI IE EI IE EI IE R 11117 NO.6 TDC COMPRESSIONSTROKE VALVE CLEARANCE SPECIFICATIONS Intake Valves Exhaust Valves 0.018 in. (0.46 mm) 0.028 in. (0.71 mm) Fig. 4-Six-Cylinder Valve Clearance Adjustment TM-1106 (Jan-79) Litho in U.S.A. Engines - 400 Series

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-------. Engine Repair Cylinder Head, Valves, and Camshaft 20-05-3 Checking Valve Lift Measuringvalve liftcan give an indicationofwear to cam lobes, cam followers, and push rods. 1. Set valve clearance to specifications as pre- viously indicated. Fig. 5-Checking Valve Clearance 3. Adjust valve clearance on No.1, 3, and 5 exhaust valves and No.1, 2, and 4 intake valves (Fig. 5). 4. Rotate flywheel 360 degrees until NO.6 piston is at "TOG" of its compression stroke, and tool timing pin engages flywheel hole. Fig. 6-Checking Valve Lift (6-Cylinder shown) 5. Adjustvalveclearance on No.2, 4, and 6 exhaust valves and No.3, 5, and 6 intake valves to the specifi- cations listed above. 2.

Place dial indicator on rotator (Fig. 6). 3. Manually turn engine in running direction (coun- terclockwise) . 4. After rocker arm contacts valve stem, observe dial indicator reading as valve is moved to full open. VALVE LIFT NEW PART SPECIFICATIONS 4270 Intake Valves. . . . . . . . . . . . . . .. 0.431 to 0.461 in. (10.95 to 11.71 mm) Exhaust Valves 0.427 to 0.457 in. (10.85 to 11.61 mm) 64040 and 64660 Intake Valves. . . . . . . . . . . . . . .. 0.424 to 0.454 in. (10.77 to 11.53 mm) Exhaust Valves. . . . . . . . . . . . .. 0.414 to 0.444 in. (10.52 to 11.28 mm) 6404T and A; 6466T and A Intake Valves. .. . . . . . . . . . . . .. 0.412 to 0.442 in. (10.46 to 11.23 mm) Exhaust Valves. . . . .

. . . . . .. .. 0.413 to 0.443 in. (10.49 to 11.25 mm) TM-1106 (Jan-79) Litho in U.S.A. Engines - 400 Series

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- - -------- u -. -- --- --- - ..- 20-05-4 Cylinder Head, Valves, and Camshaft Engine Repair CYLINDER HEAD AND VALVES Access ROCKER ARM ASSEMBLY Removal 1. Disconnect battery ground cables and drain cooling system (not shown). - I NOTE: 6466T (072864- ) and A (068223- ) engines use a one-piece rocker arm shaft clamp in place of the Nos. 1 and 2 and 5 and 6 clamps. 1. Remove rocker arm shaft clamp cap screws. NOTE: When removing rocker arm shaft compo- nents, identify for reassembly into original position. Fig. 7-Left Side Removal Steps (6466A Engine Shown) A-End Plug.. B-Oil Holes C-Adjusting Screws 2. Remove air cleaner, mufflerand exhaust elbow. Fig.

9-Rocker Arm Shaft Components (6-Cylinder Shown) 3. Remove intercooler ("A" engines) with intake manifold. 2. Remove rocker arm shaft end plugs and slide components from shaft (Fig. 9). 4. Remove turbocharger ("T"and "A"engines) with exhaust manifold. Inspection and Repair 1. Inspect rocker arm shaft for scratches, scores, or excessive wear at points of rocker arm contact. NOTE: Wear could indicate weak valve springs, bent push rods, or loose rocker arm shaft clamps. 2. Be sure that all oil holes are open and clean (B, Fig. 9). 3. Check rocker arm adjusting nut and screw for damage (C, Fig. 9). 4. Check for cups or concave wear on ends of rocker arms where they contact valve tips (A, Fig.

10). Fig. 8-Right Side Removal Steps (6466A Engine Shown) 5. Remove water manifold. 6. Remove fuel lines and leak-off line. Plug open- ings to prevent contamination. 7. Remove fuel injection nozzles. 8. Remove rocker arm cover. Engines - 400 Series TM-1106 (Jan-79) Litho in U.S.A.

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