Model 2120 Tractor TM-4252 (Dec-70) Engine 20 Cylinder Head, Camshaft, and Balancer Shafts 10-1 Group 10 CYLINDER HEAD, CAMSHAFT AND BALANCER SHAFTS GENERAL INFORMATION Disconnect both battery ground straps. The intake and exhaust valves are set in the cylin¬ der head. The valve guides are integral with the head. The valve seats are ground directly into the cylinder head. Between each valve stem and the rocker arm is a hardened stem cap. The camshaft is driven at half engine speed by the upper idler gear of the timing drives. It is suppor¬ ted by three pressure lubricated bores, integral with the cylinder block.
The camshaft has an eccentric lobe to actuate the fuel transfer pump and an axial, pressed-in lug to drive the tractormeter. Both balancer shafts are arranged in the lower half of the cylinder block. They are driven at double engine speed in opposite direction to each other, revolving in three replaceable, pressure-lubricated bushings. The right-hand balancer shaft is driven by the lower idler gear and the left by the oil pump gear. Fig. 1 - Removal of Rocker Arm Shaft Assembly 1 Rocker arm shaft 3 Cylinder head cap screws 2 Push rods 4 Valve stem caps When removing, identify parts to facilitate reinstal¬ lation.
Do not turn crankshaft after removal of cylinder head, before all liners are secured with screws and washers. DIAGNOSING MALFUNCTIONS For diagnosing malfunctions see group 5. NOTE: For comprehensive and detailed repair instructions see " Fundamentals of Service, Engines" manual. REPAIR DISASSEMBLY CYLINDER HEAD REMOVAL NOTE: It is not necessary to remove the engine in order to work on the cylinder head, valves and associated parts. Immediately cover or plug holes of all removed or exposed fuel pipes with plastic caps or plugs. Remove injection nozzles (nozzle points are protruding from cylinder head sealing face and might be damaged). Fig.
2 - Rocker Arm Shaft Assembly 1 Rocker arm support 4 Rocker arm shaft 2 Springs 5 Plug 3 Rocker arms Printed in Germany