Lego 42143 - Ferrari Daytona SP3 help?

About to go onto Bag fives of Box 2. This is where I’m up to. Enjoying the process so far, it’s stunning how all the parts come together. However these are my spare parts. Unsure about the cog? I’m scared it’s important. However all the parts are working so far, including gearbox etc. submitted by /u/Illustrious-Egg4011 [link] [comments]