1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 278Get this manual
9-25 LOWER UNIT 5Carefully pull out propeller shaft and housing to check tooth contact patternConcave side Convex side Heel Toe Tooth top Tooth bottom TOOTH CONTACT PATTERN
Tooth width
Optimum tooth contact The optimum tooth contact is shown at rightA shim adjustment may be necessary to obtain this contact pattern
Optimum tooth contact approx13 of tooth width approx1 mm HEEL
TOE Convex side
Example(1) Incorrect topside toe contactCorrection measuresDecrease thickness of forward gear shim Slightly increase pinion gear shim thickness