Ricoh D146 Service Manual page 2169

Adjustment of the Flat Fold Booklet Unit
4. Adjust the position of the flat fold lower roller [A] to adjust the difference in alignment
between the upper and lower rollers of the flat fold booklet unit.

To lower the booklet fold height (increase folding strength), roller offset is increased.
To raise the booklet fold height (decrease folding strength), roller offset is decreased.
When the machine is shipped from the factory, the booklet fold height is set low by
offsetting the rollers. However, since the folding strength is high, toner cracking
may occur at fold lines. In such a case, toner cracking at fold lines may be reduced
by adjusting the offset amount to 0 mm.
D688/D689 36 SM