The Seiko 5 Sports GMT is a new and exciting watch from the renowned Japanese watchmaking company Seiko. It’s a stylish timepiece with a unique design and an impressive range of features. The Seiko 5 Sports GMT is an automatic watch that has a GMT (Greenwich Mean Time) function, allowing you to track the time in different time zones easily. It also has a 41.5mm stainless steel case with a Hardlex crystal, a date window at 3 o’clock, and a water resistance rating of up to 100m.

But enough of that. While they’re all amazing, there’s one question you’re here to answer: can you mod it? Well, yes, you can, but there are some limitations to this.

Today, we’re going to delve into the topic of modding the Seiko 5 Sports GMT to help you make the right decisions and end up with a stunning modded watch:

1. Modding the Movement

The new 4R34 Seiko movement is designed to be interchangeable with older Seiko models, such as the 4R35 and 4R36. The main difference between the 4R34 and these other models is the addition of a taller center post to accommodate the GMT hand. To use the 4R34 movement, a crystal with enough space to fit the taller center post is needed.

2. Modding the Chapter Rings

For those wanting to mod from their SKX or SRPD chapter ring to that of the SSK GMT watches, unfortunately, it isn’t possible. The design of the chapter ring has been altered for the SSK watch models, as it is used to display a 24-hour time scale. The chapter ring is now higher profile and has an extra alignment tab and slot in the case to help prevent misalignment. Unfortunately, this means that it is not compatible with SKX or SRPD watches.

3. Modding the Dial

The 4R35 movement has a larger center post than its predecessor, the 4R34. This is necessary to incorporate the GMT hand in addition to the standard three hands for hour, minute, and second. As a result, the center hole of a dial designed for the 4R35 must be larger than those intended for the 4R34. If you would like to put a 4R34 dial onto a 4R35 movement, then the hole must be minimally enlarged, which can be done with patience and caution.

4. Modding the Bezel

The SSK watches feature a bezel that is not the standard uni-directional design found on the other Seiko 5 Sports watches. Instead, the bezel is bi-directional and, as such, not compatible with SKX or SRPD cases. This means that the bezel and case must be a matched pair, with each designed specifically for the other.

5. Modding the Crown

Seiko’s 5 Sports line of watches has changed the crown style from screw-down to push-pull. The new GMT watches from this line are equipped with push-pull crowns that are reliable and easy to grip, thanks to the quality gaskets. Watches from the SKX line use screw-down crowns, while those from the SRPD line use push-pull crowns. The SSK watches will not accept screw-down crowns.

6. Modding the Hand

The 4R34 movement is compatible with hands used in a wide variety of Seiko designs. The timekeeping hands (hour, minute, and second) used in the 4R35, 4R36, 7S26, and 7S36 models, among others, will all fit on the new 4R34. As for the GMT hand, there are not as many ready-made options available, but more diverse varieties are being produced every day.

7. Modding the Crystal

The new SSK models have a thinner crystal than the previous SKX and SRPD models due to the need for a taller center post on the 4R34 movement. The crystal can be replaced with a convex-shaped double-dome crystal to give enough room for the taller center post of the 4R34 movement to fit. This will allow the 4R34 GMT movement to be used in old-style SKX or SRPD cases.

Conclusion

As you can see, the Seiko 5 Sports GMT can be pretty much modded in and out. However, there are some changes made to the new watch that make it incompatible with certain mods. So, do your research and make the right decisions to ensure the mod parts you invest in fit your watch perfectly and result in a stunning and unique watch you can wear proudly.

Crystaltimes USA is a Seiko mod part specialist offering a variety of mod parts that Seiko owners can use to create beautiful Seiko mods. If you are looking for Seiko 5 mod parts, check out what we have to offer!

What to Know about Modding the New Seiko 5 Sports GMT