ExplorerII 16570 serial G with 3185 or 3186?

[Aspirin]

I got my ExplorerII 16570 with serial G since Sep last year, but I still not yet clarify which movement with it, is 3185 or 3186? somebody says hour hand take 8 jumps for 1 manual full wind is 3186, and I tried it that it is 8 jumps, so it should be 3186, but all the webs says ExplorerII 16570 is running by 3185, so which one is correct? I knew my car has 1400cc TSI DOHC 131 HP, sometime I feel Rolex is quite funny... about spent $$$ to get nothing for the watch.

[padi56]

Originally Posted by Aspirin

I got my ExplorerII 16570 with serial G since Sep last year, but I still not yet clarify which movement with it, is 3185 or 3186? somebody says hour hand take 8 jumps for 1 manual full wind is 3186, and I tried it that it is 8 jumps, so it should be 3186, but all the webs says ExplorerII 16570 is running by 3185, so which one is correct? I knew my car has 1400cc TSI DOHC 131 HP, sometime I feel Rolex is quite funny... about spent $$$ to get nothing for the watch.

Well thats one test to show its a 3186 but whatever it is you will get a fine movement a 3186 is only a slightly modded 3185.In the 3186 you will have the second time zone detent gear has been slightly modified. Plus it has the in-house hairspring and its movement is a very tiny bit thicker and thats it in a nut shell.Plus now one full crown turn on the 3186 will turn 8 hours on hour hand, while on the 3185 around 5 to 6 but most parts are fully interchangeable between 3185/6. And only Rolex knows for sure when they started putting the modded cal 3186 in the Explorer 11.

[George Ab]

Shelton is to thank for providing the following:
http://www.minus4plus6.com/paracromblu16710.htm

The Crown Method

Another method for discerning a 3185 with the 3186 movement is through the the Crown Rotation Method. This method is another way to discern the type of movement without having to remove the caseback. Because the calendar and hour-hand setting mechanism was redesigned in the 3186 movement, the number of turns of the crown to turn the 12 hour hand is different on a 3186 than it is on a 3185.

To perform this test, unscrew the crown such that the crown is in the hand setting position. With the crown face-up, count how many hours the hour-hand travels with one full revolution of the winding crown.

* 3185: one complete crown revolution makes the hour hand jumps 6 timezones/hours
* 3186: one complete crown revolution equals 8-9 timezones/hours

That all said, your is a 3186 as G is the random numbers. They have been using 3186 since late in Z series covering M, Z, and the random series.

[Aspirin]

Thanks padi56 & george, especially for george, that link is quite useful & practical for daily regulation.