I did the mark the driveshaft and turn the wheel one complete turn. The mark rotated 4 times. What is this ratio? 3.73? or 4.10? I can't seem to remember. Someone must remmeber what the method is...
Its not the most accurate method, but if the mark went just slightly past 4 complete rotations then it's probably 4.XX:1, just under then 3.73's or 3.90's.
If you want to know the exact ratio, pull the rear cover off, count the number of teeth on the ring and pinion, then divide the number of teeth on the ring gear by the number of teeth on the pinion gear.