20 Engine 10-8 Cylinder Head, Camshaft and Balancer Shafts Model 2120 Tractor TM-4252 (Dec-70) INSTALLATION Coat each shaft with light, clean engine oil and from the timing gear side, guide shaft into cylinder block bushings. CAUTION: Take care when doing this that the journals and bushings are not damaged. Tighten thrust plate cap screws to the specified torque (see Torques for Hardware). 40462 Fig. 14 Securing a Balancer Shaft Bushing, Using Special Tool No. JD 255 (Sectional View) d Half-round part of special tool e Top part of tool f Pin of part "e" g Oil channel h Oil bore i Oil channel k Ball 1 Bushing Remove both cap screws of special tool No. JD 255.
Turn part "e" of tool so that pin "f" fitting in oil channel "g" is directed towards the bushing and set up on cylinder block as shown in figs. 13 and 14. Insert part "d" of special tool in bushing "1" so that its rounded surface has the same radial distance from the bushing. At the same time, ball "k" should be vertically under pin "f" of part "e". The ball then lies in the bushing recess. Place both cap screws through part "e" as shown in fig. 13 and screw into part "d" evenly and finger tight so that both parts of the tool are parallel to each other, making sure that the ball is still in its correct position.
Now tighten both cap screws gradually and evenly until the rounded part "d" of tool lies against the bushing "1". In this way ball "i" has made a small bulge in the wall of the bushing, pressing the material in the oil channel "g" so that the bushing cannot move sideways or revolve. 40081 Fig. 15 Measuring Balancer Shaft "End Play" As shown in fig. 15, check that actual end play does not exceed maximum distance quoted in the Specifications. CAUTION: If the balancer shaft end play is too great, although the thrust plate is within tolerance, check whether balancer shaft gear and end face of shaft are within the tolerance quoted in Specifications.
After installing one or both balancer shafts and be¬ fore installing idler gear, align marks on balancer shaft gears with centre of crankshaft (see group 25 for details). Printed in Germany