Here is how Rack and Pinion Mechanism can be created in CATIA
Open Create_Rack2.CATProduct document.
Click the Rack Joint icon in the Kinematics Joints toolbar or select Insert -> New Joint ->Rack... from the Menu bar.
Select Prismatic.2 in the specification tree.
Select Revolute.1 in the specification tree.
Assign a command, for instance select Angle driven for revolute check box.
Click Ok to end the rack joint creation.The rack joint is created and identified in the specification tree.
Your mechanism can be simulated, a message is displayed.
Double-click Mechanism.1 to launch the simulation with commands functionality.
let's modify the ratio.
Double-click Rack.3 in the specification tree
Click the Define button.
The Rack Ratio Definition dialog box appears:
Select a circle in the geometry area. The ratio is automatically calculated.
The ratio is automatically calculated.
Click ok. Your Mechanism can be simulated.