I checked this one that I changed out a few years ago and it has wear with a lip on bottom of gear but also the shaft is worn too.
The lip and shaft are the least of your worries ... look at the wear on the gear !!!!
That gear is worn out
I totally agree.This was my first time using one and was surprised how fast it wore out. It only had 3,000 street miles on it. I added a collar now and check it much more often.
That gear is worn out 
