Sorry for the revival, but I NEEDED to say that this is an incredible must-do!
I was having issues with my trunk 'shifting' out of position when hit by the ball, and came across this thread. I took its advice and found that my gearbox had some really nasty buildup.
This task was fairly easy to do and made such an improvement in the way my ToM's trunk works, smoother, quieter and my issue was fixed.
I just wanted to say a huge thank you to cal50 for suggesting this, and throw my recommendation behind doing this to any ToM that hasn't had it done yet.
Here's my gunk: