Lewis tackles first Lego Technic set on his own

Lewis at 6 years of age is now attempting to assemble his first Lego Technic 9393 Tractor set and have succeeded up to step 23, page 25. At this point, grandpa am guessing the "train" comprising of rack and pinion, rods, a pinion supposed to be the "steering wheel" is designed to convert the rotation of the "steering wheel" about a vertical axis to the turning of the 2 front wheel. Lewis seemed to have followed the instructions correcting.

Grandpa attempted to turn the "steering wheel" but the rods would not turn nor would the rack and pinion move. Grandpa think he has isolated the problem to this part::

"2 holes perpendicular axis" Lego Technic part

 which prevent the vertical rod from rotating.

Lego offers very good support and let us see how they respond to my query about this "apparent" problem which may either be a just a small mistake.

Grandpa has attempted to locate the parts list for Lego Technic 9393 and need to refer to this yellow "4 balls" part:

Yellow "4 sphere" Lego Technic part

Now let's see how Lego support respond to grandpa's query.