Endura Case Back Question

[Mobetter]

I have a couple old mechanical divers I picked up for practice. I'd like to start with the bigger Endura but I've ran in to a problem with the case back. I can turn it with a rubber ball, but it won't come off. It seems like there is a small gap now that I've loosened the case back but I can't tighten it back down or get it to come free. I'm pretty sure it's not a snap off case back. I'm not sure what my next move should be.

[Klassiker]

My guess is, it is a screw back and the gasket is sticking. Is it loose enough to turn with your fingers, or do you still need the ball? Can you feel the tiny "snap" when you reach the end of the thread?

[Mobetter]

I can't quite turn it with my fingers. I can't feel a snap, either. 

[Neverenoughwatches]

11 hours ago, Mobetter said:

I have a couple old mechanical divers I picked up for practice. I'd like to start with the bigger Endura but I've ran in to a problem with the case back. I can turn it with a rubber ball, but it won't come off. It seems like there is a small gap now that I've loosened the case back but I can't tighten it back down or get it to come free. I'm pretty sure it's not a snap off case back. I'm not sure what my next move should be.

The case back spanner design does suggest a screw down . But thats not always the case ( scuse the pun ). Will it tighten back up with a little pressure, without pressure the gasket maybe holding it off the end of the screw thread.

[Marc]

My money would be on a snap on back dressed up to look like a screw on back for marketing purposes. The facets on the back have a distinct slope to them which would make it difficult to use a wrench without it slipping. Also the gap you have indicated with an arrow looks like a pry point.

If it is a screw on back, and you can turn it without either tightening or loosening it then the threads must be stripped.

[Mobetter]

 

I think you are on to something there. I wondered how the flats would work angled like they were. I'll try a case knife.

 

[LittleWatchShop]

4 hours ago, Marc said:

My money would be on a snap on back dressed up to look like a screw on back for marketing purposes.

My money is on Marc.

[Klassiker]

On 11/27/2022 at 2:48 PM, Mobetter said:

I can't quite turn it with my fingers. I can't feel a snap, either. 

OK, so it probably is a snap back after all. Turn it anti-clockwise wth the ball two or three turns just to be sure, then lever it off.

[LittleWatchShop]

It IS a snap back.  Here is a similar one--also a diver.  Probably an EB88xx movement as well.

[Mobetter]

Absolutely right. A bit of pain to get off carefully, but finally got two open. One is indeed an EB8800 and the other just says Chancellor Watch Inc. 

An interesting gasket on the Chancellor. I wonder how long it's been like this.