# Seiko M158-5000 Pan Am



## Sir Alan (Sep 10, 2010)

I bought this six month or so ago, but unlike me I didn't do anything with it when It arrived other than test it, set the time and wear it a couple of times.

I went to wear it mid-week and found it was dead - I assumed (and hoped!!) it was just a dead battery. I ordered 4 new ones from ebay on Thursday and they arrived this morning :thumbup:

I thought I'd take the opportunity to strip it down while I was changing the battery, give it a general clean, re-grease the pushers (the seller had noted that the top pusher was a bit sticky) and just see how this model is put together.

The battery can be changed via a small hatch on the back, removed by rotating with a suitable object such as a coin. But to get at the movement and pushers, the back needs to be removed. This is a press fit, levered off from a small indent in the bottom right corner.



The movement comes out as well:



To get the movement out of the caseback needs the crown to be removed - there is a crown release lever, more easily seen in this picture (sticking out with the dimple at approx. 9pm):



The crown is quite small - it acts as a pusher rather than to turn hands:



I removed the pushers and gave them, the caseback and the crown an ultrasonic clean. There was a fair amount of caked gunge around the holes and in the crown and pushers, but as usual this cleaned up really well.

The movement sits on this spacer ring:



which fits into the caseback:


----------



## Sir Alan (Sep 10, 2010)

Here's the case, not looking so interesting without the yellow screen:



turned over there is a movement holding ring (metal) and underneath this a black flat gasket. Its this gasket that gives the press fit case a degree of water resistance.



here are all the parts:



and the finished result:



it really could do with a new crystal, but I think these are hard to get hold of so I'm happy with it as-is.


----------



## Carepackage (May 21, 2014)

Cracking result there!


----------



## chris.ph (Dec 29, 2011)

really good :thumbup:


----------



## Carepackage (May 21, 2014)

Very retro.. Job well done I like it.


----------



## digibloke (Nov 26, 2007)

Great watch - the time zone feature is superb for Summer holidays. I especially like the way that the calender starts up in 1970 when you put a new battery in - then you can take it up to 2008 one year at a time (only to find that that was as far as Seiko programmed it so you might as well have kept it in 1970 anyway...).

Great work with getting it up and running in such nice shape. Here are a couple of mine (Gold one went out of the door a while back but I still have the steel one).


----------



## Sir Alan (Sep 10, 2010)

I put out a "want to buy" for a new crystal, not really expecting much.

I had two members from SCWF offer to help, one to fit a crystal (supplied by me) and service the watch, and the other suggesting a company called Gleave & Co. An immediate check on their pretty sparse web site indicated that they had stock. Whoa. I immediately ordered two and waited for the postie (whilst half expecting an email saying sorry, they're out of stock).

Two days later my order arrived and I had two crystals!!

Then I started to consider whether I would fit it, or I would ask the SCWF person who is an acknowledged expert on Seiko LCDs.

Given I'd bought two, I figured I'd have a go, and if the worst happened and I broke one, I'd get the second fitted properly.

If the crystal had been round, I wouldn't have hesitated doing it myself, but the rectangular shape and the fact that the dial surround creates a much smaller 'window' to push the old crystal were worrying me.

So today I had a go.

I made a wooden block that just fitted the cutout window, and I also taped over the crystal in case it cracked / shattered. This isn't something I've done before but it seemed like a good idea.

Then it was press time!!!

As usual, it was breath holding heart in mouth time as I wound the pressure up, and then ...... the crystal came out.



leaving behind the black plastic gasket and the dial surround.



I needed to get the gasket out so I could remove the dial surround - this was tricky (there's always the risk of cracking or badly deforming the gasket) but it came out.



which allowed this to come out



leaving this



As well as fitting the new crystal I wanted to re-finish the case.


----------



## Sir Alan (Sep 10, 2010)

I used 600 and 1200 wet&dry to re-finish the case, keeping a brushed effect on the two top surfaces. I used a Halfords super fine finishing pad (3000) to polish the sides (these pads btw are brilliant, they last really well and work).

Having done as good a job as I wanted, it was time to fit the new crystal



the crystal has a bevelled edge, and this helps to guide the crystal into the gasket







pressing it home was easy


----------



## Sir Alan (Sep 10, 2010)

And here's the finished result





which I'm very pleased with.


----------



## Carepackage (May 21, 2014)

Job well done there fella :-D


----------



## JD6150 (May 23, 2013)

Looks as good as new, fantastic job.


----------



## dotenconsulting (Dec 11, 2020)

I have one of these watches that I purchased in Yokota, Japan ~ 1977. The LCD display is no longer working even with a new battery. Is it possible to buy a replacement LCD display? If so, please provide details.

Thanks for any assistance.

Best regards,

Neal


----------

