Mk 7 Mech Assembly

[PedalPedantic]

I was getting my Benelux rear mech installed and adjusted, and just when I pulled the toggle chain to attach the cable to the cable anchor bolt, all of the chain tension in the mech suddenly left. I have assembled and dis-assembled the Mk7 multiple times in the past, and thought I knew everything about them. The one thing that I have my doubts about, though, is the positioning of Spring Loc. (locator?) Cup (part # 44M). There is no slot to accommodate the end of the Taper Tension Spring (part # B13), so it rides somewhat askew. Is there any particular way that the cup needs to be positioned when fitting the Retainer Cup and the mounting nut, overall?

 

[Pennine-Paul]

View: https://www.youtube.com/watch?v=xCGApjMG7Gk

Have you seen this vid from Velocipedium,It may help

 

[PedalPedantic]

If the mech let loose all its tension at once, that just means you didn't have part B16 (Large Spring Retainer Cup) snugged up all the way. The way to check is to hold the uninstalled derailleur in your hand and twist the cage a turn or two (the correct direction) to tighten the spring and see if it holds. It it doesn't release you should have no more problems. Sometimes, the tension spring gets out-of-place, and it sounds like yours was just "settling-in". Remember not to over-tighten B16