Benrus 3-Star 3021-Series Help

[NeithanOfArda]

Hello!

New to the forum, but starting to work to get my grandfather's old Benrus ticking again. 

The problem I noticed first, upon being given the watch, is that it will set time just fine, and the date complication works also, when spinning the crown forward. However, it's an automatic, and its hand-winding function isn't working. I.e., the crown will not turn clockwise at all, when it's pushed in. Some contacts on another forum suggested it may be over-wound and bound up, and the mainspring needs to be let out; or perhaps the fork is stuck; or perhaps the balance staff is broken. We shall see.

Today, I removed the crystal (doesn't have a removeable case-back), thinking I'd see some way to remove (what I assume is) a split stem. But there's nothing. The movement tilts out a little bit, but I don't see anything to push or turn or detach or anything. How do I get this movement out of the case?

Thanks in advance!!

Edited November 22, 2021 by NeithanOfArda

[Plato]

21 minutes ago, NeithanOfArda said:

Today, I removed the crystal (doesn't have a removeable case-back), thinking I'd see some way to remove (what I assume is) a split stem.

You need to pull hard on the crown to split the stem, there's special tweezers for the job but I'm sure there's other methods. 

[NeithanOfArda]

2 minutes ago, Plato said:

You need to pull hard on the crown to split the stem, there's special tweezers for the job but I'm sure there's other methods. 

Wow really? Just pull? 

[NeithanOfArda]

2 minutes ago, NeithanOfArda said:

Wow really? Just pull? 

Seems almost too easy to be true! 

[Plato]

Just now, NeithanOfArda said:

Wow really? Just pull? 

Yes, the stem just locks together. 

BUT, before trying it, wait for another member with more experience than me to confirm. I don't want you to damage your watch with bad advice. 

[Plato]

This is the stem I'm thinking of, it will just come out with force:

[watchweasol]

Hi  Most front loaders use split stems, there is a presto tool like the hand remover which will induce a straight pull. It needs to be straight and not levered as that's what breaks the stem

[NeithanOfArda]

1 hour ago, watchweasol said:

Hi  Most front loaders use split stems, there is a presto tool like the hand remover which will induce a straight pull. It needs to be straight and not levered as that's what breaks the stem

Great, thank you! I've got one of those already, so I should be set. Cross my fingers I don't break it.

[DelK]

I have a similar Benrus, and it might have a problem similar to yours. I have just progressed to the point of stem removal and taking the movement out of the case. Did you find the problem with your three-star?

Del

[Neverenoughwatches]

23 minutes ago, DelK said:

I have a similar Benrus, and it might have a problem similar to yours. I have just progressed to the point of stem removal and taking the movement out of the case. Did you find the problem with your three-star?

Del

Some Benrus are front loaders. Old mil spec dtu 2ap wore by vietnam soldiers, the battery / mechanical are also front loaders. Post up a photo of the movement so folk here can pass advice 

[DelK]

Here is the movement. Model is FE 235

 

 

Edited October 4, 2022 by DelK
clarify

[JohnR725]

On 11/22/2021 at 12:09 PM, Plato said:

BUT, before trying it, wait for another member with more experience than me to confirm. I don't want you to damage your watch with bad advice.

personally I really liked advice pull really really hard who cares the consequence. Normally on split stem's pulling hard would be fine. But there are some split stem's if you pull hard you are going to be looking for replacement components. On these particular split stem this the movement has to slide out in other words you have to somehow rotate the crown with stem to the right position so the movement will just drop out. Yes I know you can't see where that position is but somehow you're supposed to do it. So yes most the time you can pull hard but not all of the time.

 

[ManSkirtBrew]

On 10/4/2022 at 3:12 PM, JohnR725 said:

On these particular split stem this the movement has to slide out in other words you have to somehow rotate the crown with stem to the right position so the movement will just drop out.

Oh interesting. I actually just took apart a very similar Benrus, and I can confirm pulling hard worked, but when I put it back together I'm going to try this.

Edit to note my watch had the exact stem pictured by @Platoabove.

Edited October 5, 2022 by ManSkirtBrew

[Geotex]

For all three styles of Benrus waterproof cases with split stems from the 50's to 70's, the factory service information instructs the watchmaker to carefully use a tweezers to pull out/off the crown and outer segment of the stem. So for this make of watches they are meant to be forcibly pulled apart.

Having said that, nobody enjoys that prospect! As mentioned above, depending on the fit of the movement and dial in the case, it is possible on some Benrus watches to remove the crystal and then find the right orientation so that the stem joint can slide apart laterally allowing the movement to fall out.  Sometimes, even if this sweet spot of alignment can't be found when removing the movement, it can be put in place during reassembly so that at least you don't have to force things back together again. But they can be pushed together again if needed, using what the repair manual calls a "twirling" motion.

Their mil spec watches have the right geometry to allow the slide-and-drop removal, which is why the stock crown will generally have a stamped line on its surface - this "dimple" depicts the orientation and makes it easy to align the stem correctly rather than just trying to find the right spot through blind effort. However, the stem tube on many of the civilian cases extends too far into the case for the joint to be separated in that fashion, so you are left with the (careful) brute force method.

[JohnR725]

one of the problems with split stem is is ideally we need x-ray eyes. While most of them pull hard they split. then reassembling you just drop the movement and push hard providing are in the right place to snap together. But there are those that that plan doesn't work. Then unfortunately you don't really have a clue of which one you have necessarily.

here's an example of the one that pulling really hard to pushing really hard is not in your best interest

 

[Skip1965]

On 11/22/2021 at 1:40 PM, NeithanOfArda said:

Hello!

New to the forum, but starting to work to get my grandfather's old Benrus ticking again. 

The problem I noticed first, upon being given the watch, is that it will set time just fine, and the date complication works also, when spinning the crown forward. However, it's an automatic, and its hand-winding function isn't working. I.e., the crown will not turn clockwise at all, when it's pushed in. Some contacts on another forum suggested it may be over-wound and bound up, and the mainspring needs to be let out; or perhaps the fork is stuck; or perhaps the balance staff is broken. We shall see.

Today, I removed the crystal (doesn't have a removeable case-back), thinking I'd see some way to remove (what I assume is) a split stem. But there's nothing. The movement tilts out a little bit, but I don't see anything to push or turn or detach or anything. How do I get this movement out of the case?

Thanks in advance!!

NeithanOfArda, did you ever figure out why your Benrus 3021 couldn't be manually wound? I have pretty much the same watch and problem! Was it easy to fix?