Is My Mainspring Clutch Slipping?

Hello All,

A couple of months ago, I purchased a "certified pre-owned" Portuguese Chonograph (circa 2010) from Tourneau. It's beautiful, accurate, and I'm thrilled with my first truly fine timepiece. I have the following question.

As an automatic, the watch does not require winding. However, I recently tried winding it, and after a certain level of tension is achieved, I hear and feel the mainspring releasing tension (a whirring sound is heard). Is this behavior normal? On another automatic watch I owned, the crown would continue to wind infinitely, transferring tension to the mainspring only if needed.

Thank you in advance for your assistance.

Andy

That sounds normal. The clutch should slip to prevent overwinding. But what does your crown do here?

Well, the crown is tight to the casing, and doesn't wind easily. It hadn't occurred to me that I should not keep winding it, due to my previous experience with an infinite-wind model. Does that answer your question, and does the behavior still sound normal? (To be clear, when the clutch slips, it's almost an "exhale" sound that lasts about 1/4-1/2 second.)

Thanks again.

Andy

Hi Andy,
It sounds like your mainspring is slipping too easily inside the barrel due to incorrect lubrication.
You can check this by winding until you hear the noise then checking how long the watch runs without wearing it. A new watch will run for 44 hours. If yours stops before 40 hours, it could be a good indication that your diagnosis is correct.
Leo