I grew up detail stripping, cleaning and lubing a 1911 and didn't know the first thing about wheel guns when I bought my SW 642. I now know how to do basic cleaning such as after a range day (barrel, cylinder, etc) but watching the Apex trigger disassembly/reassembly video I noticed that they lubricated a few of the internals.

So the question: How frequently should I be opening up the guts of this little gun for cleaning, which parts should I be lubricating, and what should I not fiddle with while I'm in there?

Thanks in advance.

Never bothered with it, and my SW 686 continues to operate like it did on day one - is about ten years old.  Probably would not hurt after a few thousand rounds or several years.

There are lots of opinions on firearm maintenance however most modern firearms (including your S&W) do not require frequent detail stripping. This is generally done at the armorer level and above and, even then, on firearms that meet a minimum round count. Competition guns are inspected routinely (or at least should be).  Specifically, the volume, and even type of ammunition, determines cleaning frequency and level.

Generally, lubrication is geared towards metal on metal movement. That said, in most cases, less is more. Too much lube can lead to excessive residue build up and act as a magnet for dust and lint if carrying concealed. Many good intentions have led to gummed up actions.

Revolvers offer up a latitude that pistols don't when it comes to maintenance. In the case of the 642, (and with most S&W wheelguns) a drop around the trigger rebound slide helps. Another drop around the base of the crane where it enters the frame can smooth things a bit just as a drop on the ejector rod can.

With the slide plate off, I would refrain from any part removal if you're uncomfortable. Any part that you need to lube will be accessible with the slide plate detached.

A good hard copy reference to look for is Jerry Kuhnhausen's manual. Consulting the factory manual never hurts for the manufacturer's take either.

Enjoy.

When buying used I always check the screw heads on Smiths to see if someone removed the sideplate. Not that doing so is necessarily bad (or even going inside if you know what you're doing, which is easier thanks to YouTube), but it kind of raises a flag. If the screw heads are marred, a star cluster goes up.

If you're feeling nervy, go ahead and take the plate off carefully and have a look. You could even spray a light spritz of your favorite nongumming lube in there. Something that leaves a dry film would prolly be best. Or just leave it alone.

You can add lube from in front of the hammer and behind trigger. Some guys don't lube the internals at all. What does the manual recommend?

I'd learn to take the crane and cylinder out cuz that's easy. But you can eff that up too if you're not careful.

Well it's a good thing I had nothing else I needed to do tonight...

Spent the last 3 hours taking the whole thing apart, photographing it as I went along so I knew what went where, then watched a few youtube vids.

All this to treat the internals with FrogLube. Winning.

Thanks all for your advice and encouragement. I'm inclined to lighten the trigger after this experience, maybe get the Apex set.

Also, the internals were filthy, even from the factory and with only 100 rounds down the pipe. Still winning

Cool. I wouldn't get too wrapped up in trying to keep the insides super clean. 99.99% of revolvers are never stripped down during their lifetimes and they work fine.

Problem areas that can lock the thing up (e.g. Under the extractor star) are usually easy to get to.

A bit of advice from a video that Lin Trapper Alexiou did years ago:  use will smooth out far more burrs than any gunsmith will address. Good advice if you get the bug to start stoning the piece.

As others said, there is little/no reason to take them apart other than to see what it looks like or to clean one up that is pretty old or very well used.

Even then, if you aren't inclined towards working on stuff without tearing it up or losing small parts you're better off removing the grips and spraying the insides out with carb. cleaner, letting it dry and then spraying lube inside.

I've had my S&W's apart one time each.  Thousands of rounds through each (my own rounds) over the years for the M29 and M586.  The new to me K frame SS .38 I bought back in the summer was fairly dirty but you couldn't tell it by functioning though.

If you want something easy to take apart look at the Ruger guns.  The old Speed Six/Service Six double action revolvers were "modular".  Easy to take apart, the small parts are mostly contained in the "module" and they are easy to clean (detail inside cleaning) and put back together.  I'll bet the newer ones are set up the same way.

Having said that, they are still not as "smooth" as a nice S&W.

Those S&W's have such tight/well fitting sideplates you need to be careful you don't put a knick on one of the edges that mess with the fit when its time to put it back together.

Good to hear you have it apart. About the only thing that will cause
you problems is messing with the single action engagement notch
in the hammer, or the single action sear engagement surface of the trigger.
You don't really want to touch those at all. just clean & lube.
Big problems & unsafe lock-up real fast if your not well versed in trigger jobs.
Clean well, lightly lube with a good synthetic or dry graphite & you
most likely will never have to open her up again, that is, unless you
routinely wallow it around in the dirt, sand, mud. .
Good luck & kep us posted.

Revolvers tend to not require much maintenance of the action, but depending on how much you use it, and whether your carry method allows much lint to get in the action or you get it wet, usually a yearly detail clean at most is all that's needed.
If you don't use it much, you can go for years if you lube it with the correct lubricant.

I recommend applying a little grease to key areas like the hammer-trigger interfaces, bottom and back of the rebound slide, and the front of the trigger where it interfaces the cylinder stop.
This gives a smoother trigger action and insures proper lubrication that won't run off or dry out.

I used Super Lube grease and their "oil" in revolvers, and I've opened up guns that had been extensively used and had no internal maintenance for as much as 10 years and the Super Lube was still in place and still lubricating.
Most any good grade grease will work just fine.

Not to turn this into another "What's your favorite lube" post, but Super Lube is a clear-white synthetic Teflon bearing lube good from -45 to +450 degrees.
The grease is a stiff grease, and the "oil" is a thin grease-thick oil consistency that stays where it's put, won't run off, sling off, wick out, or evaporate or dry out.

If you'd like to try it, you can buy small tubes of the grease and small oilers of the oil from Midway.
I bought larger cans of the grease and 4 ounce bottles of the oil direct from Synco, the maker for customer and my own guns.

One trick for pistols to prevent corrosion, is to use a good rust preventing lube like CLP Breakfree on all inside surfaces.
I'd put a few drops of CLP on a soft toothbrush and "scrub" all surfaces.  This leaves a very thin coat that prevents rust, and the Super Lube was the actual lubricant.

With the inside protected by the very thin layer of CLP and the parts lubricated with Super Lube, a revolver will go just about forever, again, depending on the conditions you use it under.

Spray it out with Gun scrubber, scrub the barrel and cylinder, relube with CLP. Dry swab the bore and cylinders to make sure they're not too oily.

Take what apart?

Oh yeah, sometimes I take the rubber grip off to do this.

Thanks all for your help! I finally decided to open her up, since I've fallen in love with FrogLube which isn't very compatible with petroleum-based solvents and lubricants... FrogLube is plant based, nontoxic, and I've had really good luck with it on my other weapon systems.

I cleaned my S&W 642 and all its itty bitty pieces using FrogLube solvent and then treated all surfaces, including the guts, with FrogLube CLP paste, putting extra lubrication on the mainspring, the rebound slide and a few other places.

And then I took it to the range to make sure it still went bang, which it does! I also noticed that the trigger was MUCH smoother after the cleaning and lubing. Because I cleaned and treated it just the once, I will probably have to open it up again because FrogLube has this habit of pulling all the old lubricants out of the metal and leaving this nice, grimy mess to clean up. After the 2nd or 3rd time treating the metal it should be 100% good to go and never need opening up again. I'll be sure and post an update in a few months after it's been retreated and then abused fully.

Thanks again!

My first handgun purchase was a S&W 66 back in the early 70's. Carried S&W revolvers for work in the 90's.
Never did more than remove the cylinder and youe for cleaning. Yesterday I bought some gunsmith bits and removed the sideplate on my S&W Mountain revolver.
Today I will do a good scrub down and lube. Getting to know the workings is fun.

Do recognize that every time you remove the side plate on your smith that your loosening up its fit into the frame. Once or twice a year is no biggie but I'd recommend against routinely removing it as part of your normal cleaning.  Easy to pull the grips and hose out the action from the bottom and then spray some lube there, and select other openings. They really don't call for extensive precise maintenance.

Thanks, all! Great advice. Springs and high-friction points were lubed with FrogLube paste and the side plate was replaced and never removed again after a very thorough detail cleaning and treating.

As an armorer for a large agency in the Sate of Florida for many years, we had (currently unemployed) several dozen S&W revolvers (K's) among other weapons. Part of our procedure was an annual complete tear down. These guns were fired many thousands of rounds/year. They were every bit of 20-30 years old. This level of cleaning went on (still does) all that time. The guns worked perfectly and still do today. No wear issues or other problems. Of course we had to get S&W factory training every 3 years or so and we had all the tools to do the job right.

I would not tear down the average S&W, nor would I be afraid to take it down every once in a while. Done right, you will not cause any wear or problems - your call.

I tend to shoot my big bore revolvers a lot. Taking the cylinder off and lubing every thing properly after a good cleaning has become a part of routine maintenance. Take your wheelgun apart and put it back together a few times. You will learn/know more than 95% of the posters here.