Day wheel isn't functioning on slevin

[UB7]

Hey all have a quick question for you guys..I have my slevin (3719) and when I pull the crown out to change the day/date, the day wheel wont change it stops halfway and the day seems to get stuck and it isn't functioning properly. The datewheel is fine, and it changes dates properly, but the day wheel seems to get stuck halfway between days..And @ midnight, the date changes over and the day gets stuck between the 2 days so the day isn't properly lined up..And the same problem, happens when I spin the crown to change the day, when I turn the crown to change the day it doesn't properly change day's it just gets stuck and nothing happens...Is this an easy fix? I have an ETA day/dw coming, so perhaps my watchsmith can fix this problem when he goes to swap the wheels..Any feedback or help would be greatly appreciated..Thanks a bunch!

[Francisco]

It is a well know problem of the A7750.

It could be two possible reasons. First, one spring is not now in the correct place.

The black arrow is showing you that the spring is not in the correct place. It is above a piece. The spring must be pushing the left side of this piece.

Second, the daywheel needs to be fasten better against the movement. In this A7750 picture a copper piece is helping to prevent this problem.

[UB7]

Thank you Francisco..It had me worried but it is reassuring to hear that this is a common problem and an easy fix..My ETA day/dw should be here anyday than im sending it off to marrickvilleboy to swap them, so he should be able to fix this problem pretty easily while doing the swap...Thanks again for the detailed response!

[takashi]

This is a common problem! I would suggest adding that dial spacer ring. Correct ETA part nr. is : 2753 for Valjoux 7750 is priced