What do I need to do to get a gen movement into my GMT BLNR

[ViperGTS]

I am starting to do some research on modding my GMT BLNR, one of the mods I'd like to do is getting a more accurate movement. If I am correct, the gen movement has a "jumping" 24 hour hand, not one that slides between the hours (please correct me if I am wrong).

I would like to install a movement that will achieve this. I believe the movement I have now is a 21j.

I assume getting a gen movement would be difficult, I am not against getting a reputable clone. Would a clone fit? Would it require modding?

 

[d4m.test]

Interesting to know, one of the features I do like on my 16570 Explorer II is that the GMT-hand "jumps" in half hour increments (Asian ETA).

If Yours has a 21j movement it cost less than $200 and almost nothing will be compatible (hands, dial, movement ring etc.). Depending on the movement the crowntube placement (too high/too low etc.) is a big issue.

 

[KBH]

You're wasting you time. You could at fairly great expense put in a modified ETA 2836 GMT movement but it would still have the wrong hand stack and easily recognizable to anyone familiar with Rolex movements. At least your 21j movement, probably a DG 3804B, was made as an actual GMT movement and is usually quite reliable.

 

[GrapeJam]

Actually, there is a member named Misiekped (or something similar) who can take a Yuki 3135 movement and modify it using gen parts to create a 3186. It corrects the handstack and is very reliable although I believe it functions slightly different to the gen by removing the quick-set date ability. Better off PMing him though, he'll know more than I


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[KBH]

Good thought on the Yuki movement.

But:

Then, since the movement won't fit your 21j case, you can also buy either a gen, NDT or Phong case and buy gen hands to go with the movement. And also a gen dial unless you want to glue a cheap rep dial onto the new movement.

So figure on at least $4000 to $5000 to have an awesome Rolex GMT.

 

[GrapeJam]

My mistake, I misread it as he was wanting to find and transplant a 21j movement into his new BLNR case. I wasn't really too sure why someone would do that, it all makes sense now though

 

[ViperGTS]

haha Grapejam.......i read about the yuki movement and started doing some research behind that.

so basically what im understanding is i cant fit any other movement into my case because the case is designed for a 21j?

my other question is......what movement does the explorer II use? and how different does it function? I would assume it would be more along the lines of the BLNR (because they're both GMT)

 

[GrapeJam]

I actually don't know, I would assume they're the same but I could be wrong - [MENTION=66956]egroegart[/MENTION] would probably know that one, he's the explorer expert

 

[egroegart]

haha Grapejam.......i read about the yuki movement and started doing some research behind that.

so basically what im understanding is i cant fit any other movement into my case because the case is designed for a 21j?

my other question is......what movement does the explorer II use? and how different does it function? I would assume it would be more along the lines of the BLNR (because they're both GMT)

Thank you Grape. The explorer II from Noob comes with either a 21j 2813, or 23j, or Asian 2836, or swiss 2836, or the decorated 3187. The only ones I would probably stay away from are the 3187, the swiss 2836 and the 23j movements. The 21j is cheap, but reliable movement if you are on a budget, and the Asian 2836 is the very best one to get.

 

[egroegart]

oh, and it would function the same as yours.

 

[GrapeJam]

oh, and it would function the same as yours.

He shouldn't have any issues fitting the A-2836 into his 21j case either right?

I'm using an A-2836 in my latest GMT II by the way Viper, and so far so good! (but of course you always have the hand-stack issue, I don't know if the explorers stack differently

 

[Mendota]

Good points made. Just want to point out that the gen GMT movements do not have a jumping GMT hand. The GMT hand doesn't adjust. It is fixed in synch with the other hands. It is the hour hand that decouples and jumps forward and backwards. So when you are traveling you use the GMT hand as your home time and you just jump the hour hand ahead or behind however many hours you need.

 

[egroegart]

He shouldn't have any issues fitting the A-2836 into his 21j case either right?

I'm using an A-2836 in my latest GMT II by the way Viper, and so far so good! (but of course you always have the hand-stack issue, I don't know if the explorers stack differently

Yes, it can be done, but not sure if the dial will work, or it it can be modified to work. you would need new hands also and not sure what else needs changed. It's cheaper honestly to just buy the watch with the 2836 than to go through all that. I'd sell the cheap one and just get the one he wants.

 

[GrapeJam]

Yes, it can be done, but not sure if the dial will work, or it it can be modified to work. you would need new hands also and not sure what else needs changed. It's cheaper honestly to just buy the watch with the 2836 than to go through all that. I'd sell the cheap one and just get the one he wants.

Good point, the latest exp II is just over $200 at the moment isnt it?

 

[KBH]

I have an old GMTIIC that was originally a modified 2836-2 with the correct hand stack, which never worked properly. I replace that with a DG 21j GMT movement with no problem other than buying new hands and clipping the dial feet. Then later I replaced that with an ETA 2893-2 GMT movement and only had to change the hand gears to an H5 set and buy a a new GMT hand. Even with the H5 set, the GMT hand sits very close to the dial.

So going from a A21j to an ETA is doable. Going to a gen or gen clone movement, probably not.

 

[ViperGTS]

there's a lot of great information here, this is fantastic....thank you so much guys.

ill give you a little back story on what im trying to do. I want to teach myself how to tinker with these watches. I want to be able to do mods/repairs on my own. I figured movement swapping would be simple. So I purchased 2 broken watches that are currently on their way to me. One i believe is an Explorer II. I assumed that the movements in the ExII and BLNR are the same because they're both GMT.

It seems that the closest thing to a gen movement that would fit is a modified Yuki or a ETA 2893-2?

getting new hands to fit the new movement is no big deal. Handstack issue is not as concerning either....i think id rather have the

thank you [MENTION=13513]Mendota[/MENTION] for that explaination. I knew something jumps. i forgot which hand it was.

 

[egroegart]

There are different movements in reps that have the gmt function. so they may not be the same. I agree, for learning how to do it I think that's a great way to go.

 

[KBH]

When you say the hand jumps, you mean it jumps when setting the GMT time don't you? It doesn't jump during normal rotation of the hands during the day. The GMT hand follows the minute and hour hands around the dial making one smooth revolution per 24 hours.

Also, the GMT hand jumps one hour at a time but it's based on the 24 hours of the bezel, not the 12 hours of the dial. As I recall, the A21j movement also functions the same.

 

[ViperGTS]

There are different movements in reps that have the gmt function. so they may not be the same. I agree, for learning how to do it I think that's a great way to go.

What are the different movements?

im not 100% sure of the characteristics of the jumping hand. I do know for a fact that nothing jumps on the 21j.....unless the one i have is broken

 

[QueTip]

When you say the hand jumps, you mean it jumps when setting the GMT time don't you? It doesn't jump during normal rotation of the hands during the day. The GMT hand follows the minute and hour hands around the dial making one smooth revolution per 24 hours.

Also, the GMT hand jumps one hour at a time but it's based on the 24 hours of the bezel, not the 12 hours of the dial. As I recall, the A21j movement also functions the same.

It doesn't jump whilst screwed in and just wearing. It jumps when you are setting the time. On a GMT the GMT hand is being adjusted by the moving of the hour hand as on it the GMT hand is showing your home time and the hour hand the actual time at the place you are.