| Redesigned during production.
There are at least 2 different versions of instructions for this set. The differences for the second version are indicated in this inventory in the Alternate Items section with Match ID 99.
Quick overview of redesign: A special worm screw is replaced by a standard worm screw and a 5-long stop axle. The worm screw is used in the alternate model which combines this set with 42026-1. | 
inventoried this Set on Jan 9, 2014