GMT-II,16710B(PEPSI)3185 or 3186 Movement Question

[Lion]

I have a GMT-II that was bought in Sept. 2007 and the serial#is Z77xxxx. I asked on the Forum if anyone knew if I had the 3185 or 3186 Movement and people thought i had the 3185 movement. My new question is, I went to the AD today and checked out a new GMT-IIc. I unscrewed the crown to check out the movement of the hour hand and it moves just like my 2007 GMT does. So do I have the 3185 or 3186 Movement??? Any help would be appreciated!!!

[Tools]

Lion,

Nobody can truthfully answer your question because nobody knows for sure when they started fitting them (the 3186) to 16710's.... Anybody who says they know is just repeating what they might have read someplace..it is not fact.

The function of the two movements is identical. In fact, except for a couple of main-plates being thicker, and the different location for the jump hour hand detent gear, they are in fact the same...

Because the detent gear has been moved away from the hand-stack, the so called "wiggle" test is a quick way to tell if you have a 3185 (the hour hand will actually move a second or so in either direction when the crown is set in the jump position and wiggled back and forth), however, it is not a 100% accurate method to determine of you have a 3186.

If you truly want to know, have your watchmaker take the back off and look...

One of my GMT Masters has a 3175 in it:

[Lion]

Where in Chicago area can I go to have the back taken off so I can check the movement and then have it put back on and pressure tested??? THANX

[karmatp]

You can go to any Rolex AD that has a watchmaker and they should be able to do it. The fact remains that you have a fantastic timepiece, does it really matter what color your hairspring is inside?

[Andad]

Well Trevor,

You have told us that your Z799xxx has a 3185 in it. How do you know? Did you try the wiggle test? that doesn't always tell you. Did you take the back off your Z to find out? No, that doesn't seem right as why would you bother?

Is it possible that you really, badly want a 3186?

I took the back off my 'M' and put on a clear caseback. I knew it had a 3186 in it. I put the clear back on so I can have a look at this movement if I want to. Except for my posted pix and my family this hasn't been seen by anyone else and probably won't be. Why would you care if anyone else wants to confirm the movement they have in their Rolex.


Nice pix Larry.

[yannis]

Eddie where did you get a clear caseback? Can you also post a pic or two?
Regarding the question Lion asked, most people who have researched the topic 16710 with the 3186 movement have concurred that the earliest 16710s with the 3186 have appeared since Z9xxxxx. It remains to be seen whether they made some earlier than that. The wiggle test is quite accurate by the way.
This video is a 16710 with 3186
http://www.youtube.com/watch?v=WOx7bPguZgI
and this is one with the 3185
http://www.youtube.com/watch?v=76RAJWQoosE

[Andad]

I can see movement (wiggle) on both of my 3186 movements. How much more movement would make them a 3185?

www.thomaspreik.de for clear casebacks. Very nice guy to deal with.

[padi56]

Originally Posted by Lion

Where in Chicago area can I go to have the back taken off so I can check the movement and then have it put back on and pressure tested??? THANX

Just cannot see any point of getting the back of to check whatever movement you got 3185 or 3186.If your watch is running to spec and keeping good time.The 3186 is only a slightly modded 3185 and both are tested to the same COSC spec so both should keep good time.Both will keep very good time and the 3185 has been doing so for decades.There is nothing magical in the 3186 and it will make little difference whatever movement is in your watch.

[yannis]

Originally Posted by directioneng

I can see movement (wiggle) on both of my 3186 movements. How much more movement would make them a 3185?

www.thomaspreik.de for clear casebacks. Very nice guy to deal with.

Check the video Eddie the difference is noticeable!
I had the 3185 and i could easily notice the difference; the 24 hour hand, in particular, moves on the 3185 whereas it hardly moves on the 3186!

[Andad]

I have tried eight 3185's and six 3186's Yannis and I could not say for sure that the difference was consistent.

[charliec]

On my sons Pepsi Z serial the wiggle test proved inconclusive !!
All it took was 1 phonecall to Rolex St James Sq with the serail number and voila, all the details came up. Country of origin NZ, date of manufacture, etc etc inc last but not least ..........3185 movement !!!!!
So basically don't bother to remove the back, just pick up the telephone and call Rolex. I am in the UK and it seems Rolex here help their customers out 100% unlike some of the sad stories my fellow members report here from the US unfortunately.

[louie]

Originally Posted by charliec

On my sons Pepsi Z serial the wiggle test proved inconclusive !!
All it took was 1 phonecall to Rolex St James Sq with the serail number and voila, all the details came up. Country of origin NZ, date of manufacture, etc etc inc last but not least ..........3185 movement !!!!!
So basically don't bother to remove the back, just pick up the telephone and call Rolex. I am in the UK and it seems Rolex here help their customers out 100% unlike some of the sad stories my fellow members report here from the US unfortunately.

same goes to Singapore RSC..very unfriendly counter staff.I remembered the first time i sent in my GMT for checks..they pop up the case back check case,movement etc. Than return watch to me,i asked is it housed the new caliber 3186..guess what was their reply? One of the guy in suit says sorry sir,cannot reveal. Gees,i replied him this is my watch and since you guys have check the watch. You can't let me know if its the older caliber or the latest 3186 caliber?! I was so pissed,i grab my GMT from the counter and left!

[Chadridv]

Yes I know this is a resurrection, but I stumbled across this thread while simply looking for 16710 videos online. I think while a lot of the points made in this thread and frankly in general about tiny details and nuances of these watches can ring true over time, it's more than fair to examine them carefully for multiple reasons;

1. It's just fun. We're enthusiasts, and while these watches are "meant to be worn", etc. etc. there's no harm in investigating and familiarizing yourself with the tiny details that make these watches great and make this hobby so engaging.

2. For those who (more or less) said, who cares what movement is inside, can now look back on the past 6+ years and see what's happened with the demand and value separation of these particular two variants.

I know way more than the average person about Rolex and I know way less than the average WIS here on TRF. But I know facts and remember prices, and the fact is the 3186 movement in a 16710 is selling for thousands and thousands of dollars more than the 3185.

Again, I'm not trying to make a statement about which movement is better or even what separates them technically. I guess what I'm saying is, instead of belittling these tiny details, differences and observations that make for fascinating history and varying demand, let's keep our mind open and have fun. After all you could end up owning something worth twice as much as you thought if it never occurred to you to ask.

[rouxeny]

So, was it 3185 or 3186???

[Emreozcan]

Originally Posted by Lion

Where in Chicago area can I go to have the back taken off so I can check the movement and then have it put back on and pressure tested??? THANX

Do you really wanna do this? I mean, it's just my opinion but I wouldn't get my watch open just to know which movement it has. You'll eventually know when you send it for service.