Suzuki GA413 Manual page 45

0B1-20 MAINTENANCE AND LUBRICATION (4WD)
Propeller Shaft(s) Inspection
1) Check universal joint, constant velocity joint (4WD) and spline
of propeller shaft for rattle and damage. If rattle or damage is
found, replace defective part with a new one.
2) Check propeller shaft joint bolts for tightness, and retighten them
as necessary.
Refer to Section 4B or 4B1 for tightening torque.