Axle Ratio

["Hanna, Mark" <mhanna@ball.com>]

A while back there was a thread about determining rear axle ratio .
Last night I jacked up one rear wheel , marked the drive shaft , spun
the jacked up wheel one rotation and counted the drive shaft revolutions .
I was expecting to see the drive shaft rotate 4.2 - 4.5 times . Instead what
I 
saw was the drive shaft rotate almost 2 revolutions for every one revolution

of the jacked up wheel . What am I doing wrong ? And how do I determine 
the axle ratio using this method ? 
    TIA ,
          Mark Hanna
          AN5L/13731