Cal 501, thoughts on oiling this ratchet wheel

I have a cal 501 apart at the moment and the ratchet wheel connecting the crown wheel and auto winder to the barrel arbor is an assembly as below.

Working from the left, I'm calling these A to F and this is how I see it working.

The left part, A has a square hole which fits on the barrel arbor so winds the watch when it is turned. It's not clear in the photo but, D, the splined ring, has a flat to engage on A so, it drives the barrel.

There are two toothed rings, B and E, in which the springs are fixed and the end of these springs has a pawl to lock onto the splines on D so that when they turn (in one direction), they turn D and hence the arbor. When they turn the other way, the pawl slips and nothing happens. B connects to the crown wheel and E also to the auto winder.

F screws onto A and holds the assembly together and C is just a washer to keep B and E apart.

Anyway, what do we think about oiling this? When I took it apart there was oil everywhere but that was true of most of this movement....

Am thinking to use HP1300 on the inner diameter of B and E and nothing on either side of the washer. What about on the splines? These are a bit like a date ring as the pawls are clicking into the splines (or sliding depending on direction). A very small amount of HP1300 on the splines?

Cheers, Chris

The engineer in me says that any two surfaces moving against each other should be lubricated - the viscosity of that lubricant is another matter, depending on forces. I think your assessment is right other than lubricating the pawls where they contact the central gear (D) and perhaps the holes where the springs engage to alleviate friction as they compress (although they might be intended to "grab" at these points)

Thanks Stewart. For me, not the holes where the springs engage as these are fixing points just to provide a reaction to the pawl forces. It's easier to see when it's in front of you.

I think you're right about the splines. The way this works is that B turns when you turn the crown wheel and E slips. When the auto winder works, E turns and B slips. It's just due to the relative motion of D with either B or E. Anyway, there must be pawl slippage a lot of the time with one or the other so, a lubricant seems the right idea.

Hi Chris, thanks for posting this great picture of the 501 ratchet assembly. Can you please tell me- is it a right or left handed thread holding the two steel end pieces together?
Thanks, Mike.

Hi Mike

I haven't done one of these for some months but, if I'm remembering it correctly, part A turns clockwise in the view above to wind the mainspring so, B and E freewheel anti-clockwise therefore,a left hand thread on F could make sense. The complete assembly is 4701100 and I have stock of these but, all my parts are packed away as I'm moving country so difficult to find one and check. Sorry I can't be more help.

Regards, Chris

Hi Chris, thanks for that but hooray I've now got it apart! I left the assembly in WD40 all day then applied some sensible force. Guess what- it's right handed though your logic seemed entirely correct. It strikes me now that when hand winding a LH thread would be correct but when the auto is winding the opposite is the case. Omega couldn't win in other words, but it hasn't unscrewed itself so I guess they made the right decision.
Remarkable also that after nearly 60 years there's no detectable wear to the internal ratchet or the very small clicks.
As I don't know which country you are in I won't say goodbye- you may be moving to this one!
Au Revoir, Mike (London).

Well done Mike and, I'm coming back to UK from Spain in a week. We'll be over in sunny Somerset.

Hope you get your 501 back together safely.

And thanks @JimInOz .

Cheers, Chris

Hi Chris, the current forecast is wind, cloud and 13deg max. We're saving the rain for next week for you. Still time to reconsider!
It's a 505 but it's looking good. The current problem is that someone's filed off half of the pendant....
Thanks also to Jim for the pictures.
Regards, Mike.

Very helpfull! Thanks to Chris and Jim! I was just finishing to service a nice 501 and was wondering what to do with this special ratchet wheel...



By the way, I bought this watch without seeing the movement, hoping it was a bumper. Well, is was not! But I found interesting to service this 501, a very nice movement indeed!

They are very nice calibres François and it looks a nice watch👍

Now don't try and put me off! Movers arrive on Friday and all booked now...🙄

Sounds like you need a new pendant tube and that's a pain but, how about a pic of the watch?😁

Cheers, Chris

Thanks Chris!

It is a 18k solid gold French cased Omega. I know many collectors prefer Swiss cased Omega - I like them too! But vitnage French made cases are usually of very good quality as well. Actually, this case does not have the gold amount you can have in many 30 cal French cased, but it remains nice! Sorry for the little hijack!

Francois- nice watch, there's something about solid gold that appeals to my animal instincts somehow and like all the 5 hundreds so nicely finished. When I first saw a 1012 I had to lie down with the shock. Omega sacked all their watchmakers and put the accountants in charge!
Chris- I'll do some photos tomorrow. I'm about 3/4 assembled (or 'put up' I should say) at the moment. Cousins do a good range of ready made SS pendants but none totally suitable so I may end up making it from scratch. The remains of the original has a sink turned into its outer end- was there originally a rubber gland fitted in there in addition to that in the button?
Regards Mike.

Hi Chris, watch is now all together. I put in a new pendant. Also the barrel lid was loose, the hairspring out of flat, rust on the top lever pivot and centre seconds arbor- how did it get in there?- and the exit pallet needed re fixing and the hands re luminising. The bracelet is plated and the case gold capped. The so called stainless steel case middle is deeply pitted with rust mostly hidden by the gold bezel. The back is engraved for1960. Cousins supplied the generic glass- £6.95 + VAT- which fits perfectly and has the logo in the middle. Current rate is abt +10s/day so needs slowing a bit- heluva job getting the back off though.
Hope you like the watch and have brought your Arctic survival gear with you.
Regards, Mike.

Nice work on getting all that done Mike👍

These are a bit trickier than a later 60s calibre but still nice to work on. Corrosion and wear can be just about anywhere on these vintage movements but you already know that.

Very quick note as have been flat out for days with the move but Whites are here tomorrow for the second part of the load and then we should be on the ferry on Tuesday morning. From Wednesday we'll be UK residents again after 25 years... Lots of warm gear in the car!

Cheers, Chris

I believe the Bay of Biscay is very nice this time of year Chris .Best avoid breakfast. Or fly.
You'll find things have changed over here after 25 years, one being your pub is now a block of flats. Plenty more- but this is an Omega site so here's a 1030- how the mighty have fallen!
Regards, Mike.

Hi,
Would Lubeta V105 be sufficient in lubricating this ratchet wheel if it can't be taken apart, or just use 9104 on the inside of the two main wheels? Thanks in advance, Chris