That is what was at one time, your bump stops. At this time, I will caution you to make note of the windings. See the white latex spot on the windings and the case half? Mark that side in case the latex comes off. They have to go back together else the motor will run backwards. Also, you will need to clean all that junk out of the motor and the old grease that's turned to gum. That's what's coating the metal intermediate gear. The bump stops I gave you goes underneath that metal plate that holds the plastic gear onto the shaft.
I also advise that you remove the limiter switch/brush set so that you don't break the brushes off when reassembling the motor. Give me a call after 6 tonight and I'll give you more precise information so you don't have to tear it apart, again.
If you don't already have some, go get yourself a tube of Sil-Glyde Synthetic Brake Grease. It's high temp and works very well for lubricating the gears.
