Hello all. It's been 2 years since I last posted re: this rebuild. My time expander worked OK for a little bit, but then started to have binding issues pop up in random games. At that point, I took it out and disassembled again looking for the root cause. Found the following issues:
1. Motor/gearbox failed. Saw issues similar to those in this post: https://pinside.com/pinball/forum/topic/dw-mpf-warning-keep-hands-away-from-mini-playfield-tech-club. It was clear once I saw the motor whirring while the MPF was stationary.
2. This one is weird: The hub and cam were lopsided, i.e. not perpendicular. See attached picture.
Ordered replacement cam from Marco. After some grinding on the back side (the hub was hitting the horizontal bracket), the new cam moves smooth...mostly......
After aligning, I'm still having jerky movement when the MPF moves between upper level and mid level (specifically when the horizontal roller is between 12 o'clock and 3 o'clock). Jerky movement is primarily in CW direction, but you can hear the motor straining in the CCW direction as well.
Upon closer inspection, I may have a twisted horizontal bracket. See attached pics.
These were taken after the new cam was aligned per faz's guide (using outer bracket as a guide). Can't believe I didn't see this the first time around. The only thing I can assume is that this twisted bracket functioned fine with the previous lopsided cam. I don't see how this was possible as two "wrongs" don't usually make a "right", but my game ran fine until I decided to tear apart the time expander. (Figures.)
Looking for some confirmation that I need to get a new bracket. It appears Marco sells one; bad news is they're currently out of stock. Or if anyone has any other suggestions, your feedback is appreciated.