S&W model 10 disassembly,inspection,select repairs and reassembly - discussion

[Sylvan-Forge]

Carefully filed a raised edge by the damaged area and blended it as best as I could.:

Inspecting the firing pin bore, pivot bore and hand slot for burrs. Looks good.:

Cylinder stop slot looks good too.:

Put the yoke into the frame (without yoke screw). It swings smoothly, so nothing needed here.:

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[Sylvan-Forge]

The portion of the frame where the rebound slide, um, slides. If I had a stone I might try and clean the surface up a little bit, but it's ok. The contact marks indicate even contact with the rebound slide.:

The roll pin that locates the grips is sticking out a little more on the right than the left :

Brownells 1/8" roll pin punch (has a little pilot that fits into the roll pin) and a couple light taps sets things aright.:

Checking the hammer block for trueness.:

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[Sylvan-Forge]

Checking the hammer block for trueness part 2. It's good to go.:

Cleaned and Inspected the sideplate. The hammer block moves smoothly and sets slightly below flush in the guideway. All good.:

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[Sylvan-Forge]

Coming soon (hopefully tuesday): Yoke inspection, yoke endshake & alignment check. Barrel alignment check.



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[MartinS]

I don't have a Smith and Wesson. I can't wait for your next lesson. This is gunkrankism of the worst sort.

 

[Sylvan-Forge]

Uh, thanks MartinS, I think

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[Sylvan-Forge]

Clean & Inspect Barrel & Yoke :

Lewis Lead Remover Kit.:

I forgot to mention; inspect the thin area of frame underneath the barrel threads for any cracks. Preparing to clean the forcing cone with the Lewis Kit.:

Brownells 080-617-038 Range Rod Combo (Service). Used for testing barrel & barrel/cylinder alignment.:

Close up of the range rod head. Service and Match sized heads available. The heads thread onto the rod. Since this is a factory barrel I'm just using the service size.:

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[Sylvan-Forge]

Testing barrel alignment with the range rod. It's good. (Later I'll use this tool to check the cylinder alignment).:

Brownells 080-616-002 Crane (yoke) Alignment Tool.:

Very tight fit! I had to clean inside the yoke barrel very thoroughly, lightly lubricate and tap the alignment tool in (and out) with the brass/plastic hammer.:

Yoke and yoke screw in place for alignment test.:

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[Sylvan-Forge]

Hard to see, but the alignment gauge is showing that it is ever so slightly off to the 9 o'clock position (as viewed from the front). If this were over the same amount in the 3 o'clock position, it would be acceptable.:

A couple smacks with the plastic side of the hammer with the yoke in the fully extended position and alignment tool in place.:

Exactly centered! Note: For up/down adjustments, there is a simple tool shaped like a wedge. For left/right adjustments, any non-marring hammer can be used.:

Yoke function & endshake check. The 'Yoke Barrel Flange' is in acceptable contact with the frame and no yoke endshake detected. For yoke endshake correction, please see the Kunhausen book and the thread by THR member, machinisttx, http://www.ar15.com/forums/topic.html?b=5&f=18&t=63290 .:

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[Sylvan-Forge]

Here's the yoke terminology.:

Close up of the 10-14 yoke and yoke screw assembly. I believe S&W went from the older style, solid yoke screw to the yoke screw 'assembly' for models 10-9 and thereafter. The assembly has a pointed pilot that rides on a spring within the screw. If yoke endshake developes in these later models, I'd guess (but I'm not sure) that it could be corrected in much the same way as the older ones, with the exception of using a larger yoke screw, as it seems no oversized yoke screw assembly currently exists.:

 

[Sylvan-Forge]

More to follow in a few days!
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Truing the yoke face, disassembly & inspection of the cylinder parts, cylinder endshake check, cylinder endshake bearing installation, ..



Any input and critique is definitely welcome. I'm no editor, photographer or gunsmith, so if you have advice or see anything to improve or edit, please let me know. Thanks!



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[NGIB]

This is without a doubt one of the best threads I've ever seen - thank you.

I was just getting ready to do some action work on my 63 and the info & photos are invaluable...

 

[rainbowbob]

Sylvan-Forge:

I also think this is one of the coolest threads I've seen! You say you are neither a gunsmith or a photographer...I'm sure most of here vehemently disagree on both counts! Fantastic photos - and the red highlights really make the info pop out.

I love Smith revolvers and I'm fascinated by all the detail. but like many others here, I won't be trying this at home any time soon.

I look forward to the next installments.

 

[Big Mike]

Thanks for thel lesson...Mike

 

[Mickstix]

Wow, continued awesome instruction!!

Looks like the "pinned" thread is ready to have another step added to it! Hope the mods continue to accomodate you, and update the pinned thread as needed.. It would be a shame to let ANY of these lessons slip off the main page and into the archives..

 

[Sylvan-Forge]

NGIB, thank you for the kind words. If there's anything I can do to help, let me know.

rainbowbob, aww shucks, thanks!

Big Mike, your most welcome!

Mickstix, hehe! Thanks!
Mr. Williams told me to let him know when the thread is finished up and he'll update the sticky.

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Just want to send props out to Jerry Kuhnhausen. If it weren't for his book, I doubt I'd have been able to do this.

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[Brian Williams]

Mr. Williams told me to let him know

I didn't know you talked to my dad, I will have to find him.
It is Brian, and this is a great thread. If only someone loved Colts as much to do the same.

 

[Sylvan-Forge]

Brian, sorry 'bout that!

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[Sylvan-Forge]

True Yoke Barrel Face :

Brownells 713-030-000 Yoke Facing Reamer & 713-100-002 Cylinder Endshake Bearings, 0.002".:

After a couple twists with the facing tool (using lube), I deburred the edge with 600 grit E-Z Flex.:

All trued up.
Trimming the yoke barrel face creates cylinder endshake, so now I need to install cylinder endshake bearings inside the cylinder.:

Disassemble & Inspect Cylinder & Extractor Assemblies :
Found this extractor rod tool at gunsmithing-tools.com . Brownells carries one that fits multiple revolver models.:

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[Sylvan-Forge]

Prepped the tool by taking it apart and adding a little bit of lube to the washer and pre-tightening it until it would no longer slide onto the extractor rod, then backing it off so it would. Here it's shown mounted as close as possible to the cylinder and 3 fired cases inserted for supporting the extractor star. Modern day S&W extractor rods are left-hand threaded, so "righty loosey".:

Thoroughly cleaned the cylinder & extractor parts.
From the left, starting from the top: Extractor, Cylinder, Center Pin, Center Pin Spring, Extractor Spring, Extractor Rod Collar, Extractor Rod.:

Checking the center pin and extractor rod for straightness. The rod has ~0.002 wobble which I'll have to live with since I don't have any tools precise enough to do the job. (It works fine as is). The center pin rolls smoothly across an old hard-drive disk.:

Reassemble cylinder & extractor assemblies with cylinder endshake bearing :
Assemble the extractor rod + collar and center pin + spring and set it aside.:

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[Sylvan-Forge]

Dropping the cylinder endshake bearing into the cylinder.:

A couple drops of lube and seating the bearing with the yoke.:

While the yoke is still in, insert the extractor. Go easy as so you don't beat up the bearing.:

Remove the yoke. Make sure the bearing didn't come with it. Shown is the shaft of the extractor.:

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[Sylvan-Forge]

While holding the extractor in with your finger, slide the extractor spring into the cylinder. The spring fits over the extractor shaft. Twist the spring like your screwing it in to ease it's passage.:

Don't forget like me and wonder why everything won't go back together Left-hand threads!:

Assembled! Extractor star seats flush, does not protrude into the charge holes and has very slight side-to-side and up-and-down play.:

Need to temporarily reinstall the cylinder bolt. Shown is the cylinder bolt plunger and spring.:

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[Sylvan-Forge]

With the spring and plunger installed into the cylinder bolt, slide it into the frame, hammer stop end first.:

Push it back far enough to let the pivot clear the frame then press it down and guide the pivot into its bore.:

There it is.:

The pivot is flush.:

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[Sylvan-Forge]

Cylinder function check and gauging :
Install the yoke, cylinder and yoke screw. Push the extractor rod a few times to make sure it operates smoothly. Push the cylinder in and out of the frame and check that everything is smooth and locks up proper at the pivot and locking bolt ends and that the cylinder turns smoothly in and out of the frame.:

While testing, I noticed it wouldn't close very smoothly in a small range of the cylinder's rotation. I traced it to the end of the extractor rod where a small portion of the bevel angle was too steep and would hang up on the locking bolt. Had to take everything back down and make up a little turning jig (really wished for a lathe) to file a better 45 degree angle. Shown is my 'not-perfect' filed bevel, but the drag is gone. Also shown, the center pin is flush with the end of the extractor rod when pushed in flush from the cylinder end (used a large pin punch).:

Extractor rod/locking bolt overlap around 0.125 or 1/8". Good to go.:

Brownells 080-633-668 Cylinder Gauge. (Also known as a headspace gauge) 0.68 No-Go, 0.60 Go.:

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[Sylvan-Forge]

Headspace check must be made from the right side (sideplate side) only. The No-Go side of the gauge should not fit between the firing pin bushing and the cylinder. Checked 6 times, once over each charge hole.:

Go gauge passed all 6 times.:

Barrel face squareness + cylinder gap and endshake measurements using common feeler gauges.
To check for squareness, take measurements from both sides. First while pushing the cylinder toward the muzzle, then while pulling it back. Subtract the gap measurements from either side to determine endshake.
I have 0.007 and 0.008 measurements on one side and 0.008 and 0.009 on the other. So that's 0.001 endshake, which is perfect, but the barrel face is not square (visually apparant) and the gap is at or near max tolerance. I'm going to get the tools to square up the barrel face and I'll post some before and after chronograph results. Anyhow..:

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