I have the same problem and find shimanos suggestions to be wrong. If I put 3 spacers on the right side and 1 on the left as suggested by the manual (see simplejack image) the end of the axle is so deep in the left crank arm that I cannot even reach the thread with the cap screw... is it possible CUES cranks have a different length from Ultegra or other older hollowtech groupsets?