The Seiko 4R36, released in 2011, is an upgrade from the brand’s older automatic movements, such as the popular 7S26. The 4R36 is used in many modern Seiko watches, including the new Seiko 5 Sports lineup.
The 4R36 movement has an accuracy of -35 to +45 seconds per day, 21,600 vibrations per hour, 24 jewels, and a 40-hour power reserve, making it a solid caliber in entry-level Seikos. It offers additional features, such as hacking and hand-winding, and is generally regarded as a durable, workhorse movement.
Specifications
| Manufacturer | Seiko |
| Caliber | 4R36, 4R36A |
| Movement Type | Automatic |
| Diameter | 27.44 mm |
| Casing diameter | 27 mm |
| Height | 5.32 mm |
| Jewels | 24 |
| Hacking | Hackable |
| Hand-winding | Hand-windable |
| Vibration speed | 21,600 bph |
| Shock system | Diashock |
| Regulator | Etachron |
| Power reserve | ~40 hours |
| Magnetic resistance | 60 Gauss (4800A/m) |
| Winding direction | Clockwise |
| Country of manufacture | Japan |
| Watches That Use the 4R36 | Seiko 5, Seiko 5 Sports, Seiko Prospex Turtle, Seiko Monster, Seiko Baby Tuna |
4R36 Accuracy
According to Seiko, the 4R36 has an accuracy of -35 to +45 seconds per day. However, most people report their 4R36 to run much more accurately.
A Reddit user measured the accuracy of their 4R36, concluding the movement gained just 1.4 seconds per day. This is impressive, achieving near chronometer-like accuracy in such an affordable movement.
My own personal experience has been very positive, as well. All of the 4R36 movement watches I own, such as the Seiko 5 Sports SRPD95, SRPG35, and SRPH29, run within -5 to +5 seconds a day.
There is variance between these movements, however, and not all can be expected to be so accurate.
Regulating the 4R36
Even better, the 4R36 can easily be regulated to become even more accurate. This can be done yourself, with the right tools, and a steady hand, or by an experienced watchmaker.
The video below provides a step-by-step tutorial on regulating the movement.
4R36 Problems
Seiko’s movements, even their entry-level movements, are well-known for their reliability and longevity.
Many go on for years, even up to a decade, without ever needing a service. Therefore, there aren’t many reported common problems with the movement… Other than the fact it was hard to stop myself from buying more watches with it… I think I’m at 4 or 5, now.
Although unlikely, if you do experience an issue with a 4R36 movement, consult the official 4R36 instruction manual, or a reputable Seiko service center.
Setting the Time
You can follow these simple steps to set the time on a 4R36.
- Pull the crown out to the second click. This is the position furthest away from the watch. Note: For watches with a screw-down crown, you will first need to unscrew the crown.
- Rotate the crown clockwise to move the time forward, or counter-clockwise to move the time backward, until the current time is set.
- Push the crown back in toward the case. For watches with a screw-down crown, screw the crown back into the case.
Setting the Day and Date
You can follow these simple steps to set the day and date on a 4R36:
- Pull the crown out to the first click. For watches with a screw-down crown, you will first need to unscrew the crown.
- To set the day of the week, rotate the crown clockwise until you have reached the desired day. To set the date of the month, rotate the crown counter-clockwise until you have reached the desired date.
- Push the crown back in toward the case. For watches with a screw-down crown, screw the crown back into the case.
Winding the 4R36
The 4R36 movement is an automatic movement, therefore wound by the movement of your wrist.
Unlike the previous generation of movements, such as the 7S36, the 4R36 also has manual hand-winding.
How to Hand Wind the 4R36
- Ensure the crown is pushed all the way toward the case. If it uses a screw-down crown, first unscrew it.
- Rotate the crown clockwise to wind the movement.
- Continue to rotate the crown for ~40 full rotations to completely wind the watch up to its maximum, 40-hour power reserve.
Note: Unlike some hand-wind-only watches, it is not possible to overwind the 4R36 movement.
4R36 Complications
Hacking
Hacking is the ability to stop the second hand when pulling out the crown to set the time.
This allows you to more accurately set the current time down to the current second.
Hand-winding
An amazing feature of the 4R36 is its ability to be wound by hand. Thanks to the automatic mechanism, over-winding the watch will not cause damage to the caliber.
As the 4R36 is an automatic movement, the wearer’s kinetic motion should be enough to charge the 40-hour power reserve if worn regularly, but hand-winding is a nice-to-have in case you are planning to set the watch down for a day or two.
By winding it fully, you can then set the watch down for up to its maximum power reserve of 40 hours, before wearing it again, and it will still be running.
Day/Date
The 4R36 features a day/date display like just about any of Seiko’s other entry-level movements, nothing special here.
Servicing the 4R36
The 4R36 is a sturdy caliber that’s easy to maintain. This movement can last upwards of 10 years without any issues at all.
Still, it’s suggested to regularly service your mechanical watch every 4-10 years to ensure that everything is in working order.
Seiko charges $153 for a service of the 4R36 at the time of writing this article. Use the Seiko Service Center price calculator to see the live service cost of your movement.
The video below demonstrates how to service a 4R36 (the Seiko branded equivalent of the NH36 shown) movement, including disassembly, cleaning, and assembly.
Depending on which watch you own, it may be more cost-efficient to source a replacement 4R36 movement, and try to DIY a movement swap. In some rare cases, it may even be more cost-efficient to replace the watch altogether.
A new 4R36 movement can sometimes be found for under $100 on marketplaces like eBay. On average, it costs $20 to get the movement replaced by a professional. The cheaper cost involved with simply replacing a movement and the fact that you get a brand new one makes it a more financially sound option.
The video below demonstrates how to insert a 4R36 movement into a watch case that fits it.
Seiko 4R36 vs. Seiko 7S26
The Seiko 7S26, released in 1996, is older than the 4R36 and was previously used in their entry-level watches. The 7S26 is slightly thinner and features 3 fewer jewels.
The 4R36 addresses the shortcomings of the 7S26 by including hacking and hand-winding. Users have also reported greater accuracy on watches that have the 4R36.
Seiko 4R36 vs. NH36
The NH36 is the unbranded version of Seiko’s 4R36. The two movements are nearly identical, however, Seiko sells the NH36 to third parties, and can be found in microbrand watches such as San Martin and Aragon.
Seiko 4R36 vs. 4R35
The Seiko 4R35 is a low-cost movement introduced in 2010. It has the same features as the 4R36, including a vibration rate of 21,600bph, hacking, hand-winding, and 24 jewels. (Though the 4R35A has 23 jewels, it’s not as widely used as the 4R35B).
The main difference between the two is that the 4R36 features a day/date display at the 3 o’clock position, while the 4R35 only has a date display at the same position.
The 4R35 is featured in watches like some of the more affordable Seiko Presage Cocktail time.
Seiko 4R36 vs. 6R15
The 6R15 was released in 2006 as a slightly more expensive alternative to the 7S26 and, like the 4R36, featured hacking and hand-winding. Its impressive ~50-hour power reserve beats the 4R36 by 10 hours.
The 6R15 uses a Spron 510 mainspring, as opposed to the traditional mainspring found in the 4R36. Seiko claims that the 6R15 has an accuracy of -15 to +25 seconds per day, an improvement over the 4R36.
Though it shares many features with the 4R36 such as its vibration rate and the number of jewels, the 6R15 movement is often included in watches that are more expensive, such as the now-discontinued SARB series.
Replacement 6R15 movements can be found on eBay for a whopping $250
The higher cost of the 6R15 is primarily due to its better timekeeping precision, longer power reserve, and its Spron mainspring.
Seiko 4R36 vs. 6R35
The 6R35 is an upgrade over Seiko’s own 6R15. It features a much-improved 70-hour power reserve, about 30 hours greater than the 4R36. It has similar features, such as vibrations per hour, jewel count, etc., but it uses the Spron 510 mainspring.
Watches with the 6R35 are priced from $700 and onwards, such as the new Seiko Alpinists.
Seiko 4R36 Variations
4R36A
The 4R36A is no different from the 4R36. The ‘A’ suffix shows that it’s the first generation of the 4R36. If a new generation of the Seiko 4R36 is released, it will likely be called 4R36B.
Watches That Use the 4R36
Seiko 5 Sports
Perhaps the most iconic watch with the 4R36 is Seiko’s newest entry-level lineup; the Seiko 5 Sports series. It’s named ‘5’ because of its five key attributes, namely:
- Automatic movement
- Day/Date display
- Water resistance
- Recessed crown at 4 o’clock position
- Built for durability
Utilizing the 4R36 caliber, the Seiko 5 Sports divers, in particular, offer a movement upgrade over the previously similarly priced Seiko SKX watch, which included a lesser 7S26 movement.
Seiko Prospex Turtle
One of Seiko’s most famous dive watches, the Turtle series, such as references SRPE03 and SRPE05, utilizes 4R36 caliber. This lineup features a screw-down crown, a screw-down back, and water resistance up to 200m.
Seiko Monster
Released in 2012, the second generation of the Seiko Monster series uses the 4R36 caliber. These automatic watches are characterized by their eye-catching colors, screw-down crown, and 200m water resistance, making them suitable for diving.
4R36 User Manual
If you’re having trouble with your 4R36, or simply want to learn more about it, you can visit the official user manual here.
Conclusion
Seiko’s 4R36 is a rather basic, but consistent and affordable movement you can rely on.
Boasting an array of impressive complications for a movement so unaffordable, it’s no wonder that watches that use the movement are as popular as they are.
If you’re in the market for a new 4R36 caliber, you can find it often for less than $100, making it inexpensive to replace, if needed, and in many of Seiko’s entry-level offerings to this day.
Thanks for reading! Did we miss anything? Have something to share about your own experience with the 4R36?
– Anthony
Let us know what you think about the 4R36 movement below.
