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Replacing a Rolex Caseback

For years, I wrestled with the decision whether to install a clear caseback on my 16710. I had seen pictures of other clear casebacks on Rolexes such as this one by Hannes, and wanted to see the 3185 balance run. Just recently, I decided to take the plunge and go with a sapphire caseback. I had ordered a clear sapphire caseback from Thomas Preik (English version) a little more than a year ago, but chickened out on having the caseback installed and subsequently sold it. Despite selling the first caseback, I still contemplated a sapphire caseback and ordered another caseback and dove headfirst into this project. With no Rolex watchmaker storefronts in my county, I decided to take on the installation myself.

After completing two TimeZone online courses, and after reading how relatively simple the procedure is from other posts, I decided to take on this endeavour. The TimeZone courses gave me confidence in that I can open watch cases without breaking the watch. I have restored a few manual-wind watches since the TimeZone courses. If for some reason I made a mistake on my 16710, or if I needed to send the watch to a Rolex Service Center (RSC), I know that I could always install the original caseback. Before this project, I did some research by emailing others who have opened up Rolexes, and, who readily gave me pointers on the supplies this procedure would require. Most of the tools I already owned from the TimeZone courses, with the exception of the caseback removing tool.

 

Tools Required:

Some Rodico putty for fishing out any dust/dirt/smudges that might fall into the movement.

1. Caseback removal tool (more on this below)
2. Casevise
3. Jaxa wrench or caseback wrench for installing the new caseback. (I used a $15.00 eBay version)
4. Replacement caseback gasket (Rolex part number: 29-332-10 for the GMT/Sub).
5. Couple sticks of Pegwood
6. Silicon grease
7. Finger cots (optional)

 

 

All of these tools are available from the usual watch supply houses (Otto Frei, Friel and Borel, etc). Tell the supply house the case number of your Rolex and they will supply the correct gasket.

 

There are a couple of thoughts on the removal tool that I have either heard from others, or have seen. There are four caseback removal tools that are available each with advantages or disadvantages:

 

1. Bergeon Butterfly Wrench: Modeled after the original Rolex caseback removal tool, this wrench is readily available. Use with a casevise, this tool slips on the caseback and using downward pressure, unscrews the caseback.

Advanages: a no nonsense tool.

Disadvantages: Without the proper amount of downward pressure, the tool can slip causing scratches and rounding the teeth on the caseback. I had seen one watchmaker remove a caseback without any casevise using both this hands; watch in one hand and butterfly wrench in the other. He obviously knew how much pressure to use, plus he has sports a Tony Sopprano figure and upper body strength.

2. Bergeon or Horotech Press: This tool costs approx $500 and from what I understand, is a great tool from removing Rolex casebacks, but for a hobbyist this tool is overkill.

3. Cheesy EBay caseback removal wrenches that indicate Rolex: These wrenches use three pins that are really good for installing the new caseback, but not for removing Rolex casebacks. Avoid these.

4. LG OpenAll Caseback remover: I selected this one as it appears to prevent the caseback removal die from slipping and is relatively affordable. The only word of caution is that this tool works against itself. The more downward pressure you apply by screwing the press, is the amount of pressure the caseback pushes against when being removed. Be cognizant that one must unscrew the press while unscrewing the caseback or else the case threads might strip.

This tool has an option of being placed into a bench vise, or for $15 extra, comes with a base that is bolted into a bench. (Bonus points to anyone who recognizes the Concor sticker and the year; its an indication how long I have had this table)

 

The Steps:

1. Remove the bracelet: There are plenty of tutorials on removing a SEL Rolex bracelet. In these pictures, I have a two piece Martac band installed that can easily be moved out of the way. I use the Martac band while wearing the watch road cycling. One method for removing the bracelet is posted here.

	2. Place the watch head in the casevise. Pay special attention to where the cyclops is situated. Turn the watch head so that the cyclops does not rest against the casevise. 3. Select the correct size caseback die and install it into the caseback removal press (or butterfly wrench). Place the casevise into the LG caseback removal tool. Place the caseback removal press into the base, or into a vise.
	4. Line up the watch head, the casevise, the removal die and tighten all the various clamps.
	5. Turn the blue knob so that there is a fair amount of downward pressure. Insert the bar into the removal press. Gently unscrew the caseback, watching that there is enough pressure that the die does not slip, while insuring that the caseback is not being screwed into the press too tightly. Once the caseback breaks free, I slowly turn the blue press knob counter-clockwise while moving the breaking bar counter-clockwise so as to not strip the case threads. Once the caseback is fully broken loose, unscrew it by hand but, keep the caseback on the watch until you can get to a clean area to rest the watch.

 

6. Once in a clean area, rest the watch facedown on a clean surface and remove the caseback. In this image, you can see the tell-tale signs of a Rolex movement. The brown arrow shows the movement holding screw, the red arrow shows the rotor lockring, the blue arrow illustrates the balance bridge, and the green arrow shows the Rolex mainplate number.

 

7. Remove the gasket and inspect the area around the groove where the gasket rests. Dab (not rub sideways) Rodico to remove any dirt, smudges, and gunk such as the dried silicone grease shown in the left picture. Be sure to rotate the rotor over the balance using peg wood or a finger cot to prevent any dirt from falling into it.

 

8. Apply silicon grease onto the new gasket and reseat into the groove where the gasket rests. Use the peg wood to move the gasket in place.

9. Carefully rest the new caseback into the case level with the case and slowly screw the sapphire caseback using your fingers. Be sure to monitor the gasket insuring that it does not slip out of place.

10. Once the caseback is past the point of being finger tight, use the Jaxa wrench to tighten the sapphire caseback onto the case as tight as possible, just leaving a smudge more room to tighten. Gaskets and O-rings do need some room to breath.

 

Once installed, look at the caseback and the case using a 4x loupe to make sure there are no gaps.

Voila, the process is pretty straight forward and found it similar to replacing the oil and filter in one’s automobile. I found that installing a SEL bracelet without scratching the case requires more finesse than this job. (Info on replacing an SEL bracelet can be found here or here)

 

 

After purchasing the 16710, I had the watch pressure tested at the Beverly Hills RSC. Upon inspecting the original caseback, one can see the watchmakers inscriptions indicating when and where the watch was opened. The inscription reads as follows: RBH 5/07 3/008 7380 The RBH (Rolex Beverly Hills) makes sense, as does the 5/07 (date). The other numbers are greek to me. Watchmakers inscriptions on the caseback is a long held tradition that even Rolex follows.

 

Thoughts on the new caseback:

With the new caseback, I find myself looking at the back of the watch at any moment I get. I now reference the Rolex parts books and exploded views of the 3185 movement identifying parts. Folks have mentioned that a clear caseback is a tell-tale indication of a fake Rolex. Nonetheless, a Rolex connoisseur will recognize the ring used to hold the rotor in place, the Teflon coated reversing wheels, the free-sprung balance and balance bridge (vs. balance cock used on most other watches), the set screws used to hold the balance into the case, the reference number on the main-place, as well as many other distinctly Rolex details.

The sapphire caseback is rated at 200M/20ATM, it is slightly higher rated as the original caseback and less than the Sub/SD caseback at 300M. The machine quality of the sapphire caseback combined with the integrity of the Rolex case design makes me confident that the new caseback and the seal will repel water pressure as the original caseback.

The watch wears the same but rides a little higher. The original caseback made the watch ride at 12mm thick and the sapphire caseback makes the watch ride at 12.47mm. With the increased thickness of the sapphire caseback, the watch is a little higher, but not to the degree of a Submariner or a SeaDweller.

Update: In Antiquorum's Rolex Revolution Catalog, page 158 lists a Rolex transparent caseback for a GMT Ref. 1675. Click on the images for the larger pictures. It is comforting to know that even in 1962, Rolex wearers requested transparent casebacks for the same reason why I installed the one from Thomas Preik.

 

Update: Since writing this page, I have since sold this particular 16710 in favor for the M series 16710 with a 3186 movement (below).

I have worn this watch for a few week and have realized that the sapphire caseback has two distinct advantages:

1. The watch rides slightly higher which prevents the crown from digging into the wrist when worn loose.
2. It is hard to scratch the caseback when the watch is at rest on the nightstand as sapphire is much harder to scratch than the traditional 904L stainless caseback.

After installing the caseback, I asked a watchmaker to pressure test the watch which tested fine at 100M/10ATM.

This was a worthwhile project that anyone with a steady hand and controlled environment can do.

Image taken at Big Sur