phara Posted August 1, 2003 Share Posted August 1, 2003 [ Maybe this belongs in the gunsmithing section but here goes: Recently my 627 has become very sensitive to dirt on the cylinder face (the surface that faces the forcing cone). After around 100 rounds the cylinder starts to rub against the forcing cone in the same place every time. It's an area that covers about three chambers. I can see a shiny area at the circumference where the rubbing occurs. I have thoughly cleaned this area but the problem always comes back. I don't understand why this is happening. It seems to me that if a bent yoke was the problem, the rubbing would occur all around the circumference, not just is one spot. Ideas anyone? Thanks, Paul Link to comment Share on other sites More sharing options...
bountyhunter Posted August 1, 2003 Share Posted August 1, 2003 [ It seems to me that if a bent yoke was the problem, the rubbing would occur all around the circumference, not just is one spot. Not necessarily. If you use some feeler gauges between the cyl face and the forcing cone as you rotate the cyl, you will see the cylinder is probably not "true". It's more common on newer guns. It's easy to measure. Not sure how much the gun has been shot, but the first thing to do is measure the b/c gap when it's clean. It should be at least .003", about .005" is ideal. You also want to measure the cylinder end shake. Measure the b/c gap with the cylinder pushed forward and then check with it pulled back. The difference is the end shake (should be less than .002"). Bottom line: if you have too much end shake and the b/c gap is getting too tight, it means you have wear on the end of the crane tube (and inside of the cylinder) which has allowed the cylinder to move forward closer to the barrel. It can be easily fixed. A bent crane (yoke) is harder to fix. If all the end shake is minimal and the "headspace" is correct (gap between the cyl and the breech face) but your cyl is too close to the forcing cone, it means the barrel has to be set back. Gunsmith only job. Link to comment Share on other sites More sharing options...
phara Posted August 1, 2003 Author Share Posted August 1, 2003 Thanks Bountyhunter, I'll go get some gauges tomorrow. The gun has around 15,000 rounds through it. Hopefully it's the wear on the crane tube. If it is I'll be asking you about the "easy fix" you mentioned! Paul Link to comment Share on other sites More sharing options...
SRT Driver Posted August 1, 2003 Share Posted August 1, 2003 phara, It sounds like the yoke (crane) is slightly out of alignment if the cylinder is dragging on 3 consecutive charge holes. The best way to check is to get a yoke alignment gauge, Brownell's has them. To use it, remove the cylinder from the revolver and replace the yoke in the frame without the cylinder. Replace the yoke screw and insert the quage in the yoke. Tip the revolver up (barrel up) so the gauge tip (it has a nipple on the end sized to fit the center pin hole in the frame) slides down. If the yoke is straight, the nipple will slide into the center pin hole..if not it is bent. If it is bent, use a babbet bar and a wedge to realign the yoke and leave the tool in the yoke when banging on it. Hope this helps! Link to comment Share on other sites More sharing options...
phara Posted August 2, 2003 Author Share Posted August 2, 2003 Thanks for the input. I got some feeler gauges, and I just happened to have a crane alignment checker in my dusty old bunch of tools I never have used. The alignment checked out perfectly. The B/C check was where it was supposed to be (at a snug .005) but wow, the end shake was over .003! So I guess it's time to order some of those little shims that fit down inside of the cylinder. Should I get one of those facing tools also or is that really necessary? Thanks loads you all have really made my day! Paul Link to comment Share on other sites More sharing options...
bountyhunter Posted August 2, 2003 Share Posted August 2, 2003 Thanks for the input. I got some feeler gauges, and I just happened to have a crane alignment checker in my dusty old bunch of tools I never have used.The alignment checked out perfectly. The B/C check was where it was supposed to be (at a snug .005) but wow, the end shake was over .003! So I guess it's time to order some of those little shims that fit down inside of the cylinder. Should I get one of those facing tools also or is that really necessary? Thanks loads you all have really made my day! Paul If you have excessive end shake: You have to first remove the ejector rod assembly from the cylinder. There's a cheapskate way to smooth the inside surface of the cylinder that the crane tube rides on. Get your box of drill bits and find the one with the shank (smooth end) that just fits in the cylinder hole the ejector rod goes into. Get some 180# sandpaper and cut a piece that fits on the flat end of the shank and attach it with double-sticky tape. Insert and use it to smooth the cylinder surface by spinning it. Continue until the ridge is flat so the cylinder washer will lay flat inside the cylinder. Brownells sells the .002" crane tube washers. Sounds like you should put in one and re-check the end shake after you get the inside surface flat. You don't need to smooth the end of the crane tube. Link to comment Share on other sites More sharing options...
bountyhunter Posted August 2, 2003 Share Posted August 2, 2003 Thanks Bountyhunter,I'll go get some gauges tomorrow. The gun has around 15,000 rounds through it. FWIW, the end of the crane tube seems to be the place that wears fast if you let it. Based on my smiths, I estimate they grow about .001" in end shake for each 5000 rounds fired. But, it depends how well they are kept lubed. On my first 686, I didn't take the cyl off regularly to lube the end of the crane tube. It got loose pretty fast. It has maybe 20,000 rounds fired and required TWO washers of .002" each to take out the end shake. That's because I was a dufus and didn't know to lube it. Now, after every shooting, the cylinder comes off and I lube the crane tube with Militec grease. Wear is drastically reduced, in fact appears to be about zero now. Link to comment Share on other sites More sharing options...
phara Posted August 2, 2003 Author Share Posted August 2, 2003 Thanks again, the bearings are on their way. I'll let you know how it all turns out. I have to admit that even though I regularly remove the crane and lube it lightly on the side, it never occurred to me to lube the end of it! Well now I know better. Paul Link to comment Share on other sites More sharing options...
phara Posted August 12, 2003 Author Share Posted August 12, 2003 Bountyhunter's "end shake" diagnosis was right on the money. I put in the shim and the cylinder binding was a thing of the past! Thanks to bounty hunter and SRT driver for their suggestions. Paul Link to comment Share on other sites More sharing options...
benos Posted August 12, 2003 Share Posted August 12, 2003 Yea, ya'all nailed that one. 15,000 rounds? Shim 'er up and you'll be back in business. be Link to comment Share on other sites More sharing options...
Stu Love Posted August 24, 2003 Share Posted August 24, 2003 Is it necessary to take the cylinder off to properly lube the crane tube assembly or can you just put a drop or two of lube on the exposed forward areas on the crane assembly? Link to comment Share on other sites More sharing options...
phara Posted August 25, 2003 Author Share Posted August 25, 2003 Stu, Just my 2 cents worth, but I did regularly take my cylinder off during cleaning, and I lubed the sides of the crane tube. However due to ignorance I never lubed the end of the crane were it makes contact with the cylinder and this proabably was the cause of the crane tube/cylinder wear, which caused my cylinder to bind. So bottom line is this: lubing the crane tube forward areas while the cylinder is still on the gun may not get the lube to the far end of the crane tube. Maybe something like the runny aerosol Rem Oil would get it down there. But if you have the right sized screw driver, taking the cylinder off is really an easy operation. So I think that's the best way to go. Good luck, Paul Link to comment Share on other sites More sharing options...
SRT Driver Posted August 25, 2003 Share Posted August 25, 2003 Stu, Like phara said, lube the end of the crane often. Also lube the inside and outside of the crane. It does not hurt and does not take long. My m14 has many thousands of rounds through it and it does not have any end shake. It has had a bent crane and forcing cone erosion, but not endshake!!!??? Link to comment Share on other sites More sharing options...
Stu Love Posted August 26, 2003 Share Posted August 26, 2003 That's good info... I'll start removing my cylinder every so often to get a dab of lubricant down where it can do some good. Link to comment Share on other sites More sharing options...
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