ADJUSTMENT OF TOP SURFACE
1 Drive out two plain tapered pins (1) and loosen four capscrews (2).
2 Set gunner's quadrant (3) one-half turn past zero and return to zero and place on top surface of M137 telescope mount,
parallel to the two locating pins (4).
3 With the fixture and M137 telescope mount level in both directions, adjust upper subassembly and
capscrews (2) so that top surface is level within 0.5 mil as read on gunner's quadrant (3).
4 If necessary, drill and ream two new holes and insert two tapered pins (1) using punch.