Citizen 8110a mainspring barrel issue

[toptime810]

I am doing a overhaul of a vintage citizen 8110a movement and found the mainspring barrel to be slipping. The problem is I cannot figure out how to open the barrel. There is a wheel that turns freely on it but doesn’t feel right. It seems like it should have a bit of friction. Any help would be welcome. 

[Klassiker]

Cousins have a technical document with exploded diagrams and part numbers available to download. According to that, the barrel comes apart, so you should be able to get in and see If the mainspring is broken.

[Paul80]

Hi.

From the picture it looks like it splits around the middle like some Seiko barrels do, try inserting a fine knife edge in the visible split line and slowly work it around the barrel circumference.

Paul