Ian, it's not recommended. There's 540+ spring washers in the stock and you'll never get them back in there. Send it to Vern and let him fix it.

Dear SKM, Sure, you can take it apart!! Go right ahead! But if your not sure of the sequence and stacking order of these belville washers.....you will not get it right and you had better plan on two hours minimum for the stack time unless you have a fixture! Tryed to fix one for a friend...ended up sending it back to Vern @ PFS. After a technical discussion with Vern, will not take another one apart!! Truly a great recoil reduction device that is not effected by temperature change. Kudos and much more for a great product and company!..................Respectfully submitted....X-Jet Boat Bill

To Restack the washers; get a long rod that will fit thru the centre of the washers, stack the washers on the rod three concave together then three convex washers, repeat this until you have all 540 washers or 180 sets of three assembled, then holding the washers assembled on the rod insert these into the cylinder. drop the cylinder over the rod. It can be done, a rocket scientist isnot required.

It can be done, not rocket science, get a rod that will fit thru the centre of the washers about 12-14 inches long, tape the bottom so that the washers cannot fall off, stack the washers 3 convex then 3 concave on top of each other until all 540 or 180 sets of three have been installed in the rod. place the cylinder over the stacked washers on the shaft, turn over then remove the rod, washers are now into the cylinder, put the adjuster screw in and adjust and you are done. Make sure to install the lock nut after you have completed your adjustment.

Gord

Wow, not rocket science at all.

Decided to role the dice crossed my fingers, and gave it a try. I'm never one to leave good enough alone (even though I need the stock for the state shoot in another 5 days LOL).

I backed the tension screw out slowly. I wanted to back it out just enough to completely clear the threads, to determine if there was any standing tension against it, indicating stuff would fly out when I removed it. There was none. Once it cleared the threads, the screw just sat there. Slid it out, along with the long rod attached to it, and the washers just sat there.

I have a rod of appropriate diameter, but not length, so I'll procure one tomorrow. I don't want to just dump the washers out, I want to slide them out on the rod so I can note the orientation and stack design. Once i have that noted, I'll toss them all in the ultrasonic for a go, clean out the tube, and put everything back together.

I was a little scared, but as far as I can tell, there's nothing to it. It does look like there's quite a bit of water inside still (it was a DOWNPOUR I was shooting in).

I'll post back w/ my results tomorrow, fingers crossed, everything goes smoothly. I figure you can never really get in too much trouble if you put things back together exactly as they came apart (famous last words right?).

Ian,

What ultrasonic unit do you use? I was thinking about picking one up.

A pic of the washers stack properly would be awesome.

Rich- Its just a cheapie from Harbor Freight. Not as good as some of the high $ units, but perfectly adequate for what I need it for.

http://www.harborfreight.com/25-liter-ultrasonic-cleaner-95563.html

Interestingly, Lyman sells EXACTLY the same cleaner, but with their name on it, for significantly more money.

http://www.lymanproducts.com/lyman/case-prep/turbosonic-casecleaner.php

Larry- I'll do my best to take a pic when I have everything apart.

Aren't those washers stainless?

From the website:

Unaffected by weather, e.g. heat, cold, moisture, etc. No maintenance required No Oiling required

Although they are stainless, that doesn't mean they can't get wet and gummed up (they had kinda a funky smell when I pulled that tension screw). Unfortunately its not a perfectly sealed system like a hydraulic piston would be, otherwise the water wouldn't have gotten in there in the first place.

I know, its probably overkill and unnecessary, but as I said, its been 6 years since the washers have seen the light of day, and the stock has been shot in all conditions, so I think it deserves a thorough cleaning and its probably time to restack the washers anyways. Plus I'm not excited about it oozing water for the past 2 weeks, the PFS might not be able to rust, but my gun sure can.

Plus, I'm always interested to learn how things work, that way its not learning on the fly when I NEED to know how things work.

12Gage....You are quite right it is not difficult at all, I have done several without any problems. If you strip a PFS completely you may encounter temporary difficulties with the adhesives they use. Carefully applied heat works but be very careful. The downside seems to be the cost of Bellevilles if they need replacing. At the risk of irritating the manufacturer, the modern PFS is a poor copy of the original IMHO. The top 'bearing' continues to be an absolute disgrace(American Engineering usually excellent ++) but VDT has a cure. So have I ...Google Igus bearings .SteveB

DON'T EVEN THINK ABOUT DOING IT YOURSELF. HAD A FRIEND THAT TRIED IT--WHAT A MESS...SMOKIT

I took mine apart. Not on purpose, it broke when shooting. Funny feeling with the recoil, looked down and I have a zillion washers on me and on the ground.

But, as noted above, nothing money couldn't fix.

Best of luck.

Just a thought, call Vern and talk with him about it. He's very nice and would probably counsel against it, or offer some advice if you are determined to do it.

Bob

I sold a used Golf cart to a guy who loves to tinker according to his wife, I'm not sure the thing ever ran again after he got it home ... He called and told me it was my fault and he wanted his money back, I asked if he was serious and hung up on him never to hear from him again ... WPT ... (YAC) ...

Got it all apart, and the bellevilles are washing in the ulrasonic. I count 546 washers (90 stacks of 6, and a stack of 3 on each end). Dumped them loose into the ultrasonic w/ mineral spirits, then I'll dry them off and dump them in a jar of acetone for a couple seconds to remove any residue. I'm sure I have a task ahead of me restacking them, but once you know the order, a 3 year old could do it. They were super grimy when I got them out (the mineral spirits in my ultrasonic were almost clear when I started, now they are almost so black I can't see the bottom). I used a 3/16" steel rod to slide them out on, 12" long that I got from Tractor Supply.

They are stacked in groups of 3. First stack from either end points inward, then the next outward, then the next inward and so on (hope that makes sense).

For a visual it goes: > > > < < < > > >

IDK if my stock differs any from the other ones, but I really don't see how you can get in ANY trouble doing this if you take your time and don't just dump the bellevilles out without noting the orientation (although I could do that now that I know how they stack).

BTW, bellevilles are not stainless. They are black in color, are easily attracted by a magnet, and a few of them show some rust color on them (probably the only reason they didn't rust worst was b/c of w/e oil was on them and the accumulated grime.

Put them all on a cookie tray in the oven on warm to make sure they're completely dry, then I'll start restacking them.

Sturgeon- How do you know when its time to replace the bellevilles? I thought they were pretty much a lifetime thing.

"At the risk of irritating the manufacturer, the modern PFS is a poor copy of the original IMHO."

By "original" are you referring to the "old style" pfs w/ the larger top rod, or something else? The top bearing on mine is plastic (i'm assuming delrin) and hasn't caused me any problems thus far.

DONE. 26 minutes to completely restack the washers (talk about tedious, and all the while worrying that I put one too many or one too few washers in one of the stacks LOL). I wanted to time myself out of curiosity since someone here said 2 hours, and the manual says that it takes an experienced person 40 minutes. Sprayed them lightly w/ rem-oil then blew them off w/ the air compressor. Slid them in on the rod, and used the tension screw to push the rod out of the front (remove set screw in the front). All in all, took me under 2 hours start to finish, and a lot of that was time waiting for the washers to wash and dry.

Much smoother and actually a little looser now. I'm @ 10 turns, and just playing with it here at the house after assembling, it feels like I might have to make it a little tighter to replicate how it was before, I think the gunk and grime was adding to the resistance (that might explain why 10 turns on mine felt a lot different than 10 turns on my friends PFS that's only a year or so old).

All in all, probably the least complicated gun-type service I've ever done. Wouldn't hesitate to do it again, although it will be years before I need to on my gun again. Having the rod to slide the washers in and out with, and restack them on is paramount, would be impossible to do it any other way.

Thanks for the info Ian.

Ian -

Great report!

Just out of curiosity, how much does one save by not sending it back to Vern? Ron

Not sure what Vern would charge for the service, but figure around $40 just in shipping there and back, and @ least a week w/ out your stock.

Ian, Everything u did sounds great except I believe u made one mistake in assembly. PFS always states never use oil, that is why u need to add more tension. If it was min I would redo again and clean again and assemble without oil.

Skeet_man. They probably will last a lifetime if they do not sustain damage by incorrect assembly or operation.The PFS should never be operated without tension otherwise the stack will be compromised. With oily or dirty springs always make sure the tube is clear of springs before re-assembly.Oil is a contentious subject...very little very light..Ballistol perhaps ? I notice your pic shows a bent spring. However common sense should prevail. PFS will work perfectly well with a few missing springs ...do the calculation !!! Yes the one with the thicker rod. The 'bearing' may well be Delrin but it is too short. It should be a minimum of 2 1/2 time rod diameter. You have been fortunate perhaps. Patent no. US005410833A dated 5/2/1995 available from www.freepatentsonline.com is an enlightening read. My contribution is meant to help it should not be construed as a rant against the PFS ,a device which is invaluable for those who really need it. SteveB

You must search for the digits only (5410833). The patent can be seen above as a pdf.

Thanks, Joe

Thunder- It had some sort of oil on it to begin with (which I believe was the source of the funky smell). I've never put anything on it (the only thing I ever did was put some silicone on a rag and wipe it on the stainless rod, the stock was a little sticky when I first got it), which leads me to believe that they put something on it @ the factory. I didn't put very much on it to begin with, and blew it off real good w/ the air compressor, so there's virtually nothing left on the washers at this point anyways.

Ian seems like you should be ok. I had a guy oil his and it had to be rebuilt. If you talk to Vern he always states never use oil on a PFS.

Good Shooting, Andy

Does anybody know the I.D. of the top tube. I was thinking of ordering some of the Igus bushings to try.

Thanks in advance, Bill

I wonder if there is a chance you may of voided the Life Time warrantee by taking it apart and not having it done by the folks at PFS ..? WPT ... (YAC) ...

Unless a problem arose that was directly caused by me removing the washers (IE if I had to send it back to re-do the washers, or any damage that was caused if I restacked the washers incorrectly), I would expect not. Their website lists, "Limited Lifetime Warranty to original purchaser against manufacturing defects" with no caveats.

That being said, there is really little that the warranty would be useful to me for anymore, and any manufacturing defects would have shown up within 6 years I expect. There really isn't too much that isn't user serviceable or user replaceable on these stocks with a little ingenuity. In fact, I've been toying with the idea of removing the bellevilles completely and putting an air cylinder in there like the g-squared/air cushion stocks have, but I don't think there's enough room as-is, and would require some new parts be made from scratch.

Either way, I imagine I saved enough by performing this service myself to cover any work that may be necessary down the line that I can't accomplish myself. The only thing that I can see that might need work down the line that might be difficult to DIY would be the bushing on the bottom tube. I guess I'll cross that bridge if and when I get to it. The newest gen of that bushing is brass, mine is some sort of brass and plastic assy.

skeet_man , I still think the washers are likely stainless steel. Belleville washers are available in 17-4 SS. They will stick to a magnet and could even rust. PFS specs list aircraft aluminum, 17-4 SS and composite material. They are not aluminum or composite so has to be SS, they wouldn't make that slip in the spec list.

If the list is to be all inclusive of the materials used, they missed at least one, since brass is used as well...

If they aren't SS they would be a rusty mess by now.

They have a black oxide coating, which would help mitigate any rust issues, along with whatever lubricant was originally applied to them.

Doesn't really make a difference either way though.

McMaster Carr is where i bought my top bushing, but some "know how " and working in a machine shop help too, they are a good product but not rocket science.Joe