Engine body 025 038 031 076 r Fig. 78. Check measuring of measuring plastic 5 3. Remove the cap and measure the width on the pressed out measuring plastic at the widest point. Use the scale which accompanies the measuring plastic (Fig. 78). Fig. 79a. Fitting of main bearing cap MD2O10, MD2020, MD2030 1. Big-end bearing cap with 4. Main bearing cap of bevelling cast iron 2. Groove 5. Main bearing cap of 3. Top main bearing half aluminium with oil groove Max. permissible big-end bearing clearance: 0.2 mm (.0078 in). Replace the big-end bearing if the bearing clear- ance exceeds the permissible value. If necessary the journals can be ground to an undersize and oversize bearings fitted.
Big-end bearings are avail- able in two oversizes. NOTE! Check the bearing clearance again before assembly if the journals have been ground. Fitting of the crankshaft 1. Check the cleaning of the crankshaft channels and bearing surfaces, cylinder block and cap. Check also that the bearing cups and their mating surfac- 4 es have no burrs or upset ends. 2. Place the main bearing in position in the cap. Check that the lubrication holes in the top bear- Fig. 79b. Fitting of main bearing cap MD2040 i ng cups come opposite the oil channels. 1. Big-end bearing cap with 3. Top main bearing half bevelling with oil groove 2. Groove 4. Thrust washers 3.
Oil in the bearing and main bearing journals and fit the caps on the crankshaft. Note : The bevelled edge (1, Fig. 79a and 79b) should be turned forwards on all caps. 4. Fit the cap which is provided with a groove as per 5. Carefully lift the crankshaft in position in the cylin- der block. 2, Fig. 79a and 79b. Note: Tape the crankshaft gear before the crank- shaft is lifted in. The cogs can otherwise damage the bearing surfaces in the cylinder block. Note: The bearing cups provided with an oil groove (3, Fig. 79a and 79b) should be placed in the top cap. MD2O10, MD2020, MD2030: Fit aluminium caps ( with integrated thrust washers) at the far end (fly- wheel side). MD2040:
Place both thrust washers in the lower cap at the far end (flywheel side) and with the oil groove turned towards the crankshaft. 49