Thinking of removing your side-plate? Don't!

[Tony_the_tiger]

After an ammo evaluation of a s&w 640 I decided to clean it, and for some reason or other ended up removing the side-plate (by slightly tapping the grip frame).

However, in addition to the sideplate popping off, the Sear popped off too !. It appears there is a small slot in the posterior surface of the sear that holds a spring that rests against a spring slot on the anterior of the hammer. Apparently this spring keeps the sear pushed forward so it can engage the hand. If the hand is not able to engage the sear, then the the hammer will remain dormant and the firearm will not fire.

Anyways, I called S&W this morning. They indicated that the part needed (which I am overnighting from brownells) is

940-070-200WB
Bolt Plunger/Sear Spring
Mfr. Part: 070200000

(However, I have a suspicion the actual part is:
940-000-508WB
Sear Spring, MIM Hammer
Mfr. Part: 215770000)

Further discussion with S&W indicate it is part 215770000, Brownells 940-000-508WB

Here is a pic of a different J frame that shows the part (the photo is not my firearm).

Once I get it back together, I guess I'll have to evaluate it again at the range. In the meantime I'd like to warn all of you that sear springs will escape at the first opportunity, and that there is nothing much in there that cannot be oiled or cleaned out by simply removing the grips and lubing the internals from the hole there. If you're thinking about removing a sideplate, don't do it or you might just lose your sear spring... or worse!

In the meantime, for any of you familiar with J frame actions, is there any thing I should know about sear spring installation or does it pop right in? I got 2 just in case.

Best,

Triple_T

 

[Hammerdown77]

Never ever had that happen during all the S&W side plate removals I've performed, but I'm probably just lucky in that regard.

It's a real bugger when those tiny springs go flying off into the ether. Somewhere, in another galaxy or dimension, there's an entire planet covered with all the lost firearm and automobile engine springs anyone has ever lost. Along with all the lost left socks...

 

[MrBorland]

In the meantime I'd like to warn all of you that sear springs will escape at the first opportunity, and that there is nothing much in there that cannot be oiled or cleaned out by simply removing the grips and lubing the internals from the hole there. If you're thinking about removing a sideplate, don't do it or you might just lose your sear spring... or worse!

I wouldn't categorically say "don't do it", but I would say don't do it unless...

...you know how
...you have a good reason
...and you understand little bitty parts can go flying without due caution.

That said, I've not had a sear & spring pop just by removing the sideplate.

As can be seen in the pic, MIM sears just drop into the hammer, so the sear must've moved a good deal while tapping the gun to get the sideplate off. Out of curiosity, did you take all the mainspring tension off the hammer before opening the gun up? I'm thinking without tension, the hammer itself was moving laterally during sideplate removal, helping to sear to dislodge. Just a WAG, though.

BTW, when flying little parts are a possibility, I'll often do the work in a shoe box.

In the meantime, for any of you familiar with J frame actions, is there any thing I should know about sear spring installation or does it pop right in? I got 2 just in case.

The sear arrangement doesn't look different than the MIM k- through N-frame arrangement. My only suggestion is to be sure you don't kink the spring as the sear/spring go in, otherwise, the spring can/will eventually break at the kink.

Apparently this spring keeps the sear pushed forward so it can engage the hand. If the hand is not able to engage the sear, then the the hammer will remain dormant and the firearm will not fire.

Mostly correct, but it's the trigger, not the hand, that engages the sear. The hand is the doohickie attached to the trigger that pushes the cylinder.

 

[Tony_the_tiger]

Thanks for the feedback and correction. I did not relieve the mainspring/hammer spring tension before removing the side-plate. To be fair, "slight tapping" could have been more like "whacking on a table".... When I get her back together, I've giving up kitchen table gun-smithing for good (although I wasn't intending to mess with anything, just admire the internals and get some factory grease out). From what I can tell, everything is in order except for the sear spring, but I'll take it down and do another test tomorrow just to be sure.

 

[CPO15]

I'm reluctant to do the revolver disassembly thing,or even most disassembly things; the overhaul of the twin carbs on my first car ('63 Corvair) did not end well.

Here's a humorous post on the side plate and spring thing:


http://www.thetruthaboutguns.com/20...es-j-frame-dutycarry-trigger-kit/#more-143339

 

[Tony_the_tiger]

Wow, I know what that guy is going through. Thanks for the link and don't tell my wife about any of this.

 

[WardenWolf]

Little springs like that are sometimes called a "Ping****it". Because that's the sound they make, "Ping" followed by you going "**** it!".

Definition of Ping****it (Note: this site has some other less-than-appropriate definitions and phrases, but nothing obviously bad is visible from this page. I am not responsible for what you will find should you choose to dig.)

 

[MCgunner]

Is it just a 642 thing? I've had K and N frames apart a lot and never had this problem.

 

[Tony_the_tiger]

This was a 640. That said, from my limited research last night I learned that in older models, the sear spring and the sear attached to a pin in the hammer. The newer MIM versions have a sear spring slot with no pin to keep it secure. I suppose the slot and the tension of the spring on the sear are sufficient to keep it secure under normal working conditions, but with no pin make it more susceptible to negligent removal.

 

[Guillermo]

I'll often do the work in a shoe box

Good tip

 

[MCgunner]

This was a 640. That said, from my limited research last night I learned that in older models, the sear spring and the sear attached to a pin in the hammer. The newer MIM versions have a sear spring slot with no pin to keep it secure. I suppose the slot and the tension of the spring on the sear are sufficient to keep it secure under normal working conditions, but with no pin make it more susceptible to negligent removal.

Mmm, well yet another reason for me to be an "old Smith" snob. The shoe box thing does sound wise. Maybe one could cut hand holes in the ends and lay a sheet of clear plexiglass over that, but it'd be hard to get a good tap on the frame with a rubber mallet to get the side plate off if confined by a shoe box. Sounds like a wood shop project to me.

 

[rcmodel]

A clear plastic bag you can see through and work in is even better.

Still & all though, I have to agree that in 50 years of working on S&W revolvers, I have never ever had a sear spring get away and go hide.

The new S&W is most certainly not the S&W of old.

rc

 

[beatledog7]

One trick to removing the sideplate is pull the screws then tap the grip area with a rubber mallet while holding your finger over the sideplate. Might take a few tries, but it'll unseat without actually popping loose, then you can remove it while carefully minding all the boingy parts inside.

Doing all this inside a clear plastic bag seems like another good idea.

 

[R.W.Dale]

Or you could buy a ruger da revolver and not worry about all this side plate monkey buisness.

 

[Jim K]

First, never remove the sideplate without taking the tension off the mainspring (hammer spring). With the sideplate off, the hammer and trigger studs are unsupported on one side and can loosen or even break.

Second, that sear spring (yes, S&W calls that part a sear; others call it a hammer strut) can't "pop out" unless the "tapping" continues after the side plate is already off, and the sear itself comes out. It is not a common problem. FWIW, it didn't happen on the older guns because the sear was pinned in place on the hammer; with MIM parts the sear is just pushed into the hammer and can come out easily.

Jim

 

[jungle]

It is a really good idea to remove main spring tension prior to removing the side plate. The studs that position the trigger and hammer are normally supported by the side plate, cycle the action with the side plate off under full spring load puts a load on those studs, if one breaks free it is a trip back to the factory-they are pressed in and you can't do it on your kitchen table.

 

[Tony_the_tiger]

Thanks for the comment Jim & Jungle. I take full responsibility for the sear spring disengaging but I have hope I can get it all back togethor in a days time I'm posting here so I can continue learning from you all.

 

[rcmodel]

tap the grip area with a rubber mallet while holding your finger over the sideplate.

I never had any luck at all with a rubber mallet.
I tap with a hard plastic hammer, or a hard plastic screwdriver handle, or a hardwood stick.
While lightly holding the frame & sideplate between two fingers to keep it from flying off and hitting the floor!

S&W taps with a Babbitt metal bar.

One or two taps will do it if the shock load is there from a hard non-marring object to move the frame and leave the sideplate behind.

rc

 

[bikerdoc]

Thanks Tony
I am very intersted in the fix. Please follow up with the results.
Good luck!

 

[Old Fuff]

In pre-MIM hammers the little lever in question (called a "sear") was cross pinned in the hammer and couldn't go anywhere unless the pin was driven out - which was seldom necessary. Since the sear was pinned in place the spring behind it couldn't go anywhere either.

MIM hammers are designed so they can drop in the sear & spring, but they can "drop out" or fly away too.

You also have to be careful with the post-MIM revolvers so as to not loose the firing pin & spring because after you remove the sideplate they can get-away too. You can see this pin in the illustration, in the frame just in front of the upper part of the hammer face.

These issues can happen in any revolver (J, K, L, N or X) that has MIM lockwork.

For these and other reasons, the advise "Don't pop the side plate" should always be followed unless a part replacement is necessary.

 

[edwin41]

about taking of the sideplate,
recently i got hold of a smith model 14-4 , wich has been traced back on this forum to 1977.
this revolver wasnt fired or at least very little when i bought it.
the guy at the gunshop told me that its been there for a very , very long time .
should i have the internal works cleaned and regreased by a gunsmith , or is it best to leave it as it is?
ive tried to remove the sideplate myself for a bit, but its a real tight fit so i didnt proceed, i really dont wanna mess up this one !

i think the sideplate is never removed since 1977 when the factory put it on.
what would be the advise on this?

 

[rcmodel]

See post #18.

A couple sharp whacks with a hard plastic hammer or wood hammer handle will pull it, regardless of how tight it was fitted, or how long it's been on there.
And it hasn't been that long on a 1977 gun.
I got underwear older then that.

On the other hand, hosing it out with WD-40 or spray solvent, then blowing it out with compressed air, then hosing it with spray lube & blow it out again will do about as well.

rc

 

[Tony_the_tiger]

I got underwear older then that.

On the other hand, hosing it out with WD-40 or spray solvent, then blowing it out with compressed air, then hosing it with spray lube & blow it out again will do about as well.

Just to be clear, we are talking about the sideplate here, and not the underwear, right?

In pre-MIM hammers the little lever in question (called a "sear") was cross pinned in the hammer and couldn't go anywhere unless the pin was driven out - which was seldom necessary. Since the sear was pinned in place the spring behind it couldn't go anywhere either.

MIM hammers are designed so they can drop in the sear & spring, but they can "drop out" or fly away too.

You also have to be careful with the post-MIM revolvers so as to not loose the firing pin & spring because after you remove the sideplate they can get-away too. You can see this pin in the illustration, in the frame just in front of the upper part of the hammer face.

Good info, thank you for the response.

i think the sideplate is never removed since 1977 when the factory put it on.
what would be the advise on this?

The new me would remove the grip and stick an oily q tip up the hole and see if any rust comes out. If not, I'd oil it a bit and take it to the range for testing and then clean it gently when I came home and called it a great new gun. If rust comes out, I'd flush the whole thing with clp/breakfree and then spray it out with compressed air and let it sit overnight, then clean it up some more and add some oil and go range test it. Unless it was mega rusty, at which point I might have the factory check it out. Good luck!

 

[Guillermo]

we are talking about the sideplate here, and not the underwear, right?

RC cleans his underwear that way too.

The WD40 dissolves the oil stains

 

[edwin41]

thats some great advise .
i will spray wd 40 in the internals without removing the sideplate and let it sit for a while and shake it out over a white piece of cloth.
if no traces of rust come out i will blow it through with compressed air.

i could use ballistol after this cleaning , or will something else be better ?

must be great stuff this wd 40 if rc get that kind of milage out of his underwear !