76039 Mercury SHIFT CAM

Illustration 1 g03002456
Set a dial indicator with its tip on the end of the crankshaft.
Measure the side clearance by moving the crankshaft to the front and rear.
Table 1
Side clearance of crankshaft     New     0.15 to 0.35 mm (0.0059 to 0.013 inch)    
Allowable limit 0.50 mm (0.020 inch)    
If the measurement exceeds the allowable limit, replace the thrust bearings.
If the same size bearing is out of specifications because of the crankshaft journal wear, replace it with an oversize one.Oversize Dimensions of the Crankshaft Journal
Illustration 2 g03002625
Table 2
Oversize     0.20 mm (0.0079 inch)     0.40 mm (0.016 inch)    
Dimension A     C2.6 - 37.50 to 37.70 mm (1.476379 to 1.4842 inch)
C3.3B - 41.10 to 42.10 mm (1.619 to 1.657 inch)     C2.6 - 37.60 to 37.80 mm ( 1.48031 to 1.48819 inch)
C3.3B - 41.20 to 42.20 mm (1.622 to 1.661 inch)    
Dimension B     C2.6 - 26.20 to 26.25 mm (1.03149 to 1.03346 inch)
C3.3B - 28.20 to 28.25 mm (1.111 to 1.112 inch)     C2.6 - 26.40 to 26.45 mm (1.03937 to 1.04134 inch)
C3.3B - 28.40 to 28.45 mm (1.119 to 1.120 inch)    
Dimension C     2.8 to 3.2 mm radius (0.11 to 0.12 inch radius)    
The crankshaft journal must be fine-finished to higher than (0.8S).    Crankshaft Alignment
Illustration 3 g03002696
Support the crankshaft with V block on the surface plate and set a dial indicator with its tip on the intermediate journal at right angle.
Rotate the crankshaft on the V block and get the misalignment (half of the measurement value).
Table 3
Crankshaft alignment     Allowable limit     0.02 mm (0.0008 inch)    
If the misalignment exceeds the allowable limit, replace the crankshaft.Oil Clearance between Crankpin and Crankpin Bearing
Illustration 4 g03002756
(1) Plastigage
Clean the crankpin and crankpin bearing.
Put a strip of plastigage on the center of the crankpin.
Install the connecting rod cap and tighten the connecting rod bolts to the specified torque, and remove the cap again.
Measure the amount of the flattening with the scale, and get the oil clearance.
Table 4
Crankpin outside diameter     New     C2.6 - 46.980 to 46.991 mm (1.84960 to 1.85004 inch)
C3.3B - 49.980 to 49.991 mm (1.9678 to 1.9681 inch)    
Table 5
Oil clearance between crankpin and crankpin bearing     New     C2.6 - 0.011 to 0.058 mm (0.00043 to 0.00228 inch)
C3.3B - 0.017 to 0.048 mm (0.00067 to 0.0018 inch)    
Allowable limit 0.20 mm (0.0079 inch)    
If the oil clearance exceeds the allowable limit, replace the crankpin bearing.
If the same size bearing is useless because of the crankpin wear, replace it with an undersize oneNote: Never insert the plastigage into the crankpin oil hole.Note: Be sure not to move the crankshaft while the connecting rod bolts are tightened.Undersize Dimensions of Crankpin
Illustration 5 g03002839
Table 6
Undersize     0.20 mm (0.0079 inch)     0.40 mm (0.016 inch)    
Dimension A     3.3 to 3.7 mm radius (0.13 to 0.14 inch radius)     3.3 to 3.7 mm radius (0.13 to 0.14 inch radius)    
Dimension B     1.0 to 1.5 mm relief (0.040 to 0.059 inch relief)     1.0 to 1.5 mm relief (0.040 to 0.059 inch relief)    
Dimension C     C2.6 - 46.780 to 46.791 mm diameter (1.84173 to 1.84216 inch diameter)