You have the right idea that'll definitely help. There is a post somewhere in the T2 owners club thread that details the process with pictures. Do a search and I'm sure you can find it

It's gummed up. You need to take it apart and clean it up and it'll be good as new. The grease in there gets old and thickens, sometimes hard and it prevents smooth and quick action. Common issue.

https://pinside.com/pinball/forum/topic/terminator-2-slow-cannon-problem

https://pinside.com/pinball/forum/topic/t2-gun-cannon-speed

I have not dealt with this issue, but you might check the posts linked above. Also, while it doesn't provide instructions, the diagram of the cannon in the manual may provide a little help. If you don't have it, you can download it from ipdb.com.

Good luck!

Ha...I took this pic in the Thread March 30 2015...never got around to doing it...but I hope it helps you....(thumbs up)............Joey

BA0B806C-A261-4CC6-8837-E7F85508EEB2 (resized).png

Hi Jamie.. I have a similar issue re. not hitting the lowest target. Can only reach as low as second last target.
I removed the e clip but still couldn't remove the shaft. Then I tried adjusting switches and all kinds of things before giving up.

If you have any luck with the above, could you please post the solution. Thanks