A primer on diagnosing GMT and Submariner bezel assembly issues

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A primer on diagnosing GMT and Submariner bezel assembly issues

Post by springer »

Below is a primer that I put together a while ago for a forum member on TRF that was having issues with a GMT 1675 bezel/insert assembly. While most of the information here is directed toward acrylic crystal GMTs, the same diagnosis and issues can apply to the vintage Submariners with the acrylic crystals - such as models 5512, 5513, 1680 and some of the earlier models also.


The crystal retaining ring, which is what the bezel snaps on to, can cause many bezel issues if it becomes worn. When this happens, the bezel itself does not fit as tight as it should and the bezel may pop off when it is struck against a wall or door jam. While the crystal retaining ring can be replaced if it becomes worn, there is an old watchmaker's trick that may be used to tighten these crystal retaining rings so the bezel assembly fits tight to them once it is pressed back on to the retaining ring. (I'll discuss the method for tightening the bezel crystal retaining ring later in this post.)

Additionally, the bezel itself can become worn from years of wear. Proper diagnosis for ill-fitting bezels should be properly diagnosed to determine if it is the bezel, crystal retaining ring or even the flat spring causing loose fitting or bezel binding issues.

The four parts of the bezel assembly are:

1) crystal retaining ring
2) the flat spring
3) bezel ring
4) bezel insert


If these four parts are not in sync and fit properly, bezels can become too loose causing the bezel to fall off or the bezel might become too tight causing excessive friction on the bezel assembly to the extent that it will not turn properly. A couple of these parts can affect whether the bezel is too loose or too tight. When a bezel becomes too tight, it does not turn properly or does not turn at all. Sometimes the fix for a bezel assembly that turns too hard or not at all might be as simple as the removal of the bezel and bezel flat spring assembly and giving them both a good cleaning removing years of dirt, grime, soap scum and DNA.

The installation of the bezel assembly on the watch head is as follows:

A) The crystal is fit to the watch
B) Once the crystal is installed, the crystal retaining ring is press fit over the crystal causing a tight seal to prevent water from entering through the crystal.
C) The bezel flat spring is then placed over the top of the crystal retaining ring
D) Next, the bezel insert is snapped or pressed into the bezel. This can normally be done by pressing the insert into the bezel with your thumbs, or, with plastic/nylon tipped pliers, a round pencil or other make-shift tool.
E) Finally, the bezel assembly (the bezel and insert) is press fit onto the crystal retaining ring with your fingers or possibly a special bezel press which is made for this purpose. Personally, I have never found the need to invest in a bezel press, push fitting the bezel/insert assembly on to the watch with my fingers has always worked for me.

My watchmaker here in Dallas, who has been servicing various Rolex models for over 50 years, with 10 years as a technician at the Rolex Service Center in Dallas, told me once while discussing a poorly fit GMT bezel assembly that the biggest problem working on GMTs at the RSC were the bezel assemblies.

He said that the bezels and/or assembly parts caused more grief for the technicians that he cared to say. He said they were always replacing crystal retaining rings or bezels that did not fit properly after a watch was disassembled, serviced and reassembled.

There is a Rolex tool that can be used on the bezel assembly to tighten loose bezels. Also, crystal retaining rings can be "blipped" with a punch on or near the edges in four spots (usually the 12, 3, 6 and 9 positions) which will spread the metal outward on the retaining ring thereby giving the bezel more area to grip to on the retaining ring.

One other area that can create problems with the bezel assembly is the flat spring. If a bezel assembly turns very hard, the excess friction could be from the flat spring. One way too check this is to remove the bezel/insert assembly and flat spring - then reinstall the bezel assembly without the flat spring. If the bezel turns much better, the flat spring is causing too much tension and binding. The flat spring needs to have a small amount of metal removed from the outer diameter by turning it on a lathe. This should be done in very small increments. If too much metal is removed from the flat spring, the bezel assembly will turn too freely and the flat spring will need to be replaced.

Below are a few photos depicting the parts that I have discussed in this post. Hopefully this will help others in diagnosing bezel issues in the future.

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