The Watch Site banner

1 - 20 of 32 Posts

·
Registered
Joined
·
1,188 Posts
Discussion Starter #1
Well, I have been itching to work on a Seiko 6138 cal chronograph so I took a gamble and picked up this honest and well used Bullhead from an ebay seller in AU. While the watch shows wear, the case lines appear sharp. Crystal is in decent shape and a bit of polishing will make it like new. The dial and hands appear in exceptional condition for their age. I see no servicing marks inside the case back. The case back seal is flat and hard so it looks original to the watch. The chrono functions all work properly. I am suspect that one of the pushers is not original to the watch and may have been replaced with an aftermarket piece but cannot say for certain until I disassemble the watch. I believe original pushers have a slight chamfered edge near the tip. Let me know if I am wrong about this. Watch needs service but is not running that bad for its age. Bezel appears original to the watch but yellow indices have long since faded. Let me know thoughts and insights on condition and the originality of this piece.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #4
Chronograph pushers. Note the one on the left which I believe to original. Slight groove just below the pusher o-ring and chamfered edges near the top of the pusher. The pusher on the right while similar does not have these characteristics. These pushers do appear to be built differently than 6139 pushers. If anybody has a spare 6138-0040/49 OE pusher in their parts inventory they can spare, please let me know. i am willing to compensate for the item. Thanks.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #5 (Edited)
So I contacted forum member Acidstain and he had a couple of OE 6138 pushers to sell me. I have completed the refinish work on the case, bracelet, and crystal but I am waiting on some new seals before assembling and taking pics for posting.

I disassembled the movement this evening and everything was pretty straight forward until I got to the mainspring barrel assembly. There is a small intermediate hour wheel gear and spring on the lower part of the barrel attached to the barrel cover. The tech guide shows this and states it is fixed to the mainspring barrel cover. I did some research on-line and found you do not want to remove that gear. The barrel arbor has a shaft that slips through that gear port on the mainspring barrel cover. Once you crack open the top of the barrel, slip a thin sharp knife in to hold the spring in place and gently slide the barrel cover off. The gear will remain attached to the barrel cover and the mainspring arbor will remain attached to the spring and main body of the barrel. See photo below.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #7 (Edited)
First, for those in the US, let me wish you all happy 4th of July Independence Day. Got the Bullhead up and running this morning. With the holiday yesterday, I spent a few hours assembling the keyless works and the motion side of the movement. One thing I found very difficult with this build was placing the additional calendar pate on the calendar side of the movement after assembling the hour recording wheel hammer and springs and placing the hour recording wheel in place which is under spring tension. The hour recording wheel pinion sticks up through a very small port in the calendar plate and you have to guide the plate down over the assembly making sure the hour recording wheel pinion slides through the small port in the plate all while not managing to dislodge the hour recording wheel from it's setting. Took me several attempts and about 30 - 45 minutes of fiddling around before I was successful. All in all, very pleased with the progress and results thus far. Will post numbers once I let the movement run in for 24 hours.

PS - When I installed the balance assembly and set the movement in motion this morning, it ran for about a minute and then ground to a stop and would not restart. After a few minutes of checking my work, I found that late last night when installing the upper chrono bridge, I had only tightened 2 of the three screws'; the 2 on the left of the plate while the 3rd on the right was loose. Upon snugging up the 3rd screw on the right, the movement set in motion and was off to the races. Had me worried for a moment. Just goes to show how uneven tension on a plate can put the movement in a bind.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #8
Just realized, in this picture the return spring for the flyback reset button is not entirely routed properly. I realized this when I went to put the upper chrono plate on last night. The tight bend to the left of the spring wrapped around the upper plate mounting hole should actually wrap around the spring retention post just up and left of where it sets in this picture. Sorry for the error on my part, but wanted to point the error out for others who may be looking in.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #9
Posting pics of the case work. Original crystal polished and new crystal seal installed. Case was given a very conservative light polish and the brushing was redone on the entire case. Note radial brushing on the panel at the 6 o'clock. Sides of the case have lateral brushing and this extended around the top of the case where the pushers and crown are located. Lots of taping involved here using 3mm wide watchmakers tape.
 

Attachments

·
Premium Member
Joined
·
9,171 Posts
beautiful work John ....
 

·
Registered
Joined
·
1,188 Posts
Discussion Starter #11
Put the calendar mechanism together and mounted the dial and hands this morning So far so good. I must say the 6138 stretched the limits of my patience, especially assembly the calendar side of the movement. Everything on the calendar side must be absolutely perfect in order for it to function properly; keyless works, hour recording wheel hammers and spring, etc. I was literally two steps away from completing the calendar side last night and found the day wheel spur was not engaging the gear to change the day wheel. Had to pull the entire calendar plate off and remove the setting lever so I could adjust the small shepherd spring that controls the setting spur correctly. Will likely go easier on the next one but this has certainly been a learning experience for me. Letting the watch run in a bit and making sure everything with the chrono functions properly and resets to zero before casing the watch. More to follow.
 

Attachments

·
Registered
Joined
·
1,188 Posts
Discussion Starter #13 (Edited)
Time Grapher results with movement cased. Given this watch is over 40 years old and I cleaned and reused the original mainspring, I am pleased with the results. Have I achieved better, yes, but overall good timekeeping performance for my first 6138 service. I ran into some issues with some rusted pins on the bracelet so I am soaking it in WD40 and have some tools on order. Hope to bring you a wrist shot later this week. Thanks for looking.
 

Attachments

·
Registered
Joined
·
6,156 Posts
Excellent work...thank u for sharing it...can not wait to see it on your wrist...God Bless,John
love the metal finishing too...
 

·
Registered
Joined
·
1,188 Posts
Discussion Starter #17
Well, after soaking the bracelet in WD40 for a few hours, I managed to remove the 2 split pins on the two links I needed to remove to size the bracelet. A wrist shot puts a wrap on this project. An interesting timepiece and design concept to say the least. Very cool. :cool:
 

Attachments

·
Registered
Joined
·
6,156 Posts
well if u ever want to take one some metal finishing...i have a 6105 case that would love to look like your work...with my hands not what they should be and with my eyes even worse...i am scared to even try metal work like i used too...love to see someone making it look as it should...i know how hard it can be to do this too..God Bless,John...we all thank u for sharing it with us...gives us all hope...
 

·
Registered
Joined
·
1,188 Posts
Discussion Starter #20 (Edited)
well if u ever want to take one some metal finishing...i have a 6105 case that would love to look like your work...with my hands not what they should be and with my eyes even worse...i am scared to even try metal work like i used too...love to see someone making it look as it should...i know how hard it can be to do this too..God Bless,John...we all thank u for sharing it with us...gives us all hope...
John - I would be happy to take a look at your 6105 case for you. I will PM you with my contact info if you are interested. I always try and take a conservative approach to case refinishing; no large buffing wheels or the sort. Everything I do is by hand with some light sanding using a small square blocking dowel and various grits of wet/dry sandpaper (600, 1000, 1500, 2000, 3000, 5000) and light polishing using only my hand held dremel tool and some buffing pads with Wenol Metal Polish and then a final rub using a Cape Cod cloth. Brushed finishes are usually achieved using a 3M Super Fine Scotchbrite pad (Grey). I am not going for perfection but what looks aesthetically pleasing to my eye. Thanks for your kind words and continued support.
 
1 - 20 of 32 Posts
Top