Volkswagen Air Cooled 1949-1969 Repair Guide

Crankshaft and Connecting Rods


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Fig. Fig. 1 Exploded view of the oil pump and camshaft driving gears mounted on the crankshaft

The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

Removal of the crankshaft requires the removal of the cylinder heads, cylinders, pistons, the splitting of the crankcase halves, and the withdrawal of the camshaft. When installing the crankshaft, check to see that the crankcase does not have sharp edges at points of junction. If foreign matter has become lodged in the main bearings, it will be necessary to remove it with a scraper, taking care not to remove material from the bearing shell itself. Check the dowel pins for tightness. Place one half of the No. 2 crankshaft bearing in the crankcase. Slide on crankshaft bearing No. 1 so that the dowel pin hole is toward the flywheel. Install the crankshaft, making sure that the dowel pins are correctly seated in the crankshaft bearings. When installing the camshaft, note the marks on the timing gears.

After the crankshaft has been removed and clamped into position, remove the connecting rod clamping bolts and the connecting rods and caps.

When installing, check the connecting rods for external damage and for weight. The difference in weight of the connecting rods in an engine must not be in excess of 0.35 oz. (10g) in order that proper engine balance can be maintained. If necessary, metal should be removed from the heavier connecting rods at the points indicated on the accompanying illustration.

Inspect the piston pin bushing. With a new bushing, the correct clearance is indicated by a light finger push fit of the pin at room temperature. Check and, if necessary, correct the connecting rod alignment. Reinsert the connecting rod bearing shells after all parts have been thoroughly cleaned and the connecting rods have been assembled onto the crankshaft. The identification numbers stamped on the connecting rods and bearing caps must both be on one side.

New connecting rod screws should always be used, and the wax removed from the screws before they are installed.

Tighten the connecting rod bolts to the specified torque. A slight pretension between the bearing halves, which is likely to occur when tightening connecting rod bolts, can be eliminated by light hammer taps. The connecting rods, lubricated with engine oil prior to assembly, must slide on the crank pin by their own weight. The connecting rod bushings must not be scraped, reamed or filed during assembly. Using a peening chisel, secure the connecting rod bolts in place.


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Fig. Fig. 2 The crankshaft end-play is controlled by three shims (No. 7) of specific thicknesses

With the engine installed, the crankshaft end-play can be read with a dial indicator mounted at the pulley side of the engine. End-play should be as specified with an upper wear limit of 0.006 in. (0.15mm). When the engine is not installed, crankshaft end-play can be measured at the flywheel end with an indicator mounted on the flywheel. Desirable end-play is obtained by adding or subtracting shims at the outer end of the main bearings. Shims for this purpose are available in various thicknesses. Never use more than three shims. Install the paper or metal gasket, or the oil seal, depending on your model-year endine.