Is it time to replace my safety lever springs?

[Mr310]

I recently cleaned out my 6906 as best I could. I took apart everything except the sights and extractor and cleaned everything out. The only spring I replaced was the recoil spring, though. Since then, every time I decock the weapon, I hear the same sort of 'sproing' noise that an AR buffer spring makes sometimes. Does this mean the springs are due to be replaced or is it just because there's no more gunk to deaden the sound in there? I cleaned out a LOT of gunk.

 

[BLUEDOT37]

Not being familiar with the noise an AR buffer spring makes, & just guessing why it started after you "took everything apart", could the decocker/safety problem be than you mixed up the plungers on the decocker? Did you get the rounded one & the flat one in the correct locations?

.

 

[D Rock]

Never seen a worn out spring there but sometimes the safety lever detent gets mixed up with the safety lever plunger.

2nd EDIT: Got my pictures working again. Here's a better shot.


1st EDIT: Sorry, can't get my photobucket to work so I put this link in to show the picture.

Dave

 

[Mr310]

Sorry for the delay. I only get home late at nights and I'm already ready for bed! I took off the right side safety and there's no nub period!

 

[GaryS]

Here is a picture of my right side safety lever, plunger, and spring.

It seems to be different than yours, but it might just be the way your picture looks. I've never had this gun apart, so it's not likely that I have the parts backward. Of course, the previous owner might have, but it's unlikely I think.

If you decide to replace one or both of those parts, there is a guy selling them on Ebay. You can always call the factory to see if they have them. Which might be less expensive or even free.

The S&W part number for the spring is 10602000
The S&W part number for the plunger is 237750000

 

[Fastbolt]

The manual safety body plunger and spring are on the left, and the revised ambi lever plunger and spring are on the right.



You can see how the body plunger spring is much heavier than the ambi lever spring. It can't easily be compressed between your fingers, while the ambi lever spring can be.

New ambi plunger springs are painted light blue.

Body plunger springs are unpainted.

The original ambi lever plunger looked similar to the body plunger, having a machined shoulder below the head, but the end was flat (not fully rounded like the body plunger). Mixing up the early plungers could result in a grinding noise during decocking/lowering the safety levers, as the flat top of the ambi plunger wouldn't move as smoothly inside/against the slide as the round top of the correct body plunger.

The later, revised ambi lever plungers have a straight profile and a wide head. The levers were machined differently to fit the heads of the different plunger shapes. (I can't remember the last time I looked at a 645 ambi lever/plunger, but I was once told the .45's may have gotten the got the straight ambi lever plunger first, before the 9/.40 guns.)

Mixing up the springs can result in a couple of problems, too.

First, putting the heavy body plunger spring under the ambi lever is difficult, as the spring doesn't compress as easily as the proper, lighter ambi lever spring. If an armorer can't easily compress the spring in order to slide the ambi lever in place ... that's a hint the wrong spring is under it.

Second, the lighter ambi lever spring isn't strong enough to properly tension the manual safety/decocker body plunger when recoil forces are acting on it. The usual symptom of having switched springs, and having the ambi lever spring under the body plunger, is that when the slide cycles the gun can "decock" itself, and levers remain in the On-Safe condition as the slide returns forward. The ambi lever spring doesn't have enough strength to properly power the body plunger to prevent the manual safety/decocker body from rotating (lowering the levers, as it were) as the slide slams to the rear.

Don't laugh, as it can happen. I once knew someone at an another agency where a newly minted junior armorer made this mistake when inspecting some duty pistols, except it wasn't discovered until the next range training/qual session ... when officers' guns started decocking themselves when fired, and remained On-Safe. Yes, they'd been carrying those guns around on-duty before it had been discovered.

Not being able to inspect your 6906, I can't know what noise you're hearing, and what it might mean, if anything. (A clean gun can make some louder noises than a gummed up, cruddy gun, though.)

As an armorer, I've never experienced either of those plunger springs "wearing out", even on early 3rd gen guns we had in-service since '89/'90, but then my exposure was on a small sampling of maybe 500 guns (and later on a similar number of TSW's that replaced the early guns).

Doesn't mean a spring couldn't have been damaged at some point, or defective. They're just springs.

Got a gunsmith in your area who is familiar with S&W TDA pistols, who could inspect it?

 

[D Rock]

Thanks, Fastbolt. Good information as always.

Dave

 

[GaryS]

Does this mean that my ambi lever and spring are earlier production? The OPs looks like the one in your photo, not mine.

The manual safety body plunger and spring are on the left, and the revised ambi lever plunger and spring are on the right.



You can see how the body plunger spring is much heavier than the ambi lever spring. It can't easily be compressed between your fingers, while the ambi lever spring can be.

New ambi plunger springs are painted light blue.

Body plunger springs are unpainted.

The original ambi lever plunger looked similar to the body plunger, having a machined shoulder below the head, but the end was flat (not fully rounded like the body plunger). Mixing up the early plungers could result in a grinding noise during decocking/lowering the safety levers, as the flat top of the ambi plunger wouldn't move as smoothly inside/against the slide as the round top of the correct body plunger.

The later, revised ambi lever plungers have a straight profile and a wide head. The levers were machined differently to fit the heads of the different plunger shapes. (I can't remember the last time I looked at a 645 ambi lever/plunger, but I was once told the .45's may have gotten the got the straight ambi lever plunger first, before the 9/.40 guns.)

Mixing up the springs can result in a couple of problems, too.

First, putting the heavy body plunger spring under the ambi lever is difficult, as the spring doesn't compress as easily as the proper, lighter ambi lever spring. If an armorer can't easily compress the spring in order to slide the ambi lever in place ... that's a hint the wrong spring is under it.

Second, the lighter ambi lever spring isn't strong enough to properly tension the manual safety/decocker body plunger when recoil forces are acting on it. The usual symptom of having switched springs, and having the ambi lever spring under the body plunger, is that when the slide cycles the gun can "decock" itself, and levers remain in the On-Safe condition as the slide returns forward. The ambi lever spring doesn't have enough strength to properly power the body plunger to prevent the manual safety/decocker body from rotating (lowering the levers, as it were), as the slide slams to the rear.

Not being able to inspect your 6906, I can't know what noise you're hearing, and what it might mean, if anything. (A clean gun can make some louder noises than a gummed up, cruddy gun, though.)

As an armorer, I've never experienced either of those plunger springs "wearing out", even on early 3rd gen guns we had in-service since '89/'90, but then my exposure was on a small sampling of maybe 500 guns (and later on a similar number of TSW's that replaced the early guns).

Doesn't mean a spring couldn't have been damaged at some point, or defective. They're just springs.

Got a gunsmith in your area who is familiar with S&W TDA pistols, who could inspect it?

 

[MWater]

I also have a 6906 with a safety plunger spring that produces quite the amusing zingggggg sound. Very quiet, but certainly noticeable.

Mixing up the springs can result in a couple of problems, too.

First, putting the heavy body plunger spring under the ambi lever is difficult, as the spring doesn't compress as easily as the proper, lighter ambi lever spring. If an armorer can't easily compress the spring in order to slide the ambi lever in place ... that's a hint the wrong spring is under it.

Second, the lighter ambi lever spring isn't strong enough to properly tension the manual safety/decocker body plunger when recoil forces are acting on it. The usual symptom of having switched springs, and having the ambi lever spring under the body plunger, is that when the slide cycles the gun can "decock" itself, and levers remain in the On-Safe condition as the slide returns forward. The ambi lever spring doesn't have enough strength to properly power the body plunger to prevent the manual safety/decocker body from rotating (lowering the levers, as it were) as the slide slams to the rear.

Well, that clears up a mystery for me. My first 5906, I ordered a bunch of springs from Brownell's, including for the safety plunger spring. After putting everything back together, it did indeed go to safe about 10% of the time when firing. I figured I must have mixed up springs and ordered another one... same problem. Eventually I got a Wolff spring and it has been fine.

 

[Fastbolt]

Does this mean that my ambi lever and spring are earlier production? The OPs looks like the one in your photo, not mine.

GaryS, send me your email ([email protected]) and I can send you some pics and additional info which I can't post on the forum. Let me know it's you in the header.

 

[Fastbolt]

I also have a 6906 with a safety plunger spring that produces quite the amusing zingggggg sound. Very quiet, but certainly noticeable.



Well, that clears up a mystery for me. My first 5906, I ordered a bunch of springs from Brownell's, including for the safety plunger spring. After putting everything back together, it did indeed go to safe about 10% of the time when firing. I figured I must have mixed up springs and ordered another one... same problem. Eventually I got a Wolff spring and it has been fine.

Don't feel like the Lone Ranger. Even armorers can make that mistake, especially lesser experienced ones, if they don't have their manual open in front of them and remember the warnings discussed in class. Sometimes it may only take a moment's distraction, and not having had the parts on the bench in front of you for a while.

For the longest time, when I was disassembling slides (usually to clean out heavily gunked firing pin channels in issued weapons which hadn't been properly cleaned by the users, or their privately owned guns), the first thing I did when I removed the ambi safety lever, lever plunger and spring was to sit them off to one side, clearly away from other parts.

Then, just to be doubly sure, when I removed the manual safety assembly (meaning the body, the body plunger and its spring), I sat those parts at the other side of my mat, towel or bench work-space, far away from the ambi lever, plunger & spring.

Doesn't mean I didn't double check with the issued MkI eyeball before reassembly, either. Little parts can sometimes grow legs (or levitate) and move when you aren't looking.

Or ... some other armorer might come along and decide to start looking at what you're doing, picking things up and not putting them back down where they came from.