Removing recoil spring on PM40

[ssmokn]

Hi Folks,

I'm looking for some instructions, pictures and/or video on disassembly of the PM40 guide rod to remove the inner recoil spring. I'm looking to replace both the inner and outer but I've been unable to find information on exactly how to take apart the guide rod.

Any information or links would be greatly appreciated. I've tried searching this forum as well as searching via Google but I'm only seeing info. on replacing the outer spring (not inner).

Thanks!

[muggsy]

The end of the recoil spring assembly that sticks out of the slide is actually a nut that is held in place with Locktite. It's not recommended that you remove it and it's not generally necessary to replace the inner spring. If you are bound and determined to replace it you will probably have to heat the nut to remove it. I'd say that it would be a better bet to replace the recoil assembly as a unit rather that to replace the individual springs.

[ssmokn]

I'm interested in trying a Wolff higher rate (20.5 lb) recoil spring set (stock being 19 lb).

The PM40 has about 500 or 600 rounds through it. It's properly cleaned and oiled. After the first box (50 rounds) of ammo I start having problems with the slide going into full battery. Seems to stop with another 1/8" to go (I can easily push into battery with my thumb at this point).

After reading your post and looking closer at the guide rod it appears that the center pin of the guide rod is threaded at the front and the 'nut' is the tapered round piece that holds the inner spring and out sleeve together on the inner ping.

I agree that some heat on this nut is required. The bummer is that there is no center hex screw or anything similar. I appears that I'll have to hold and compress the outer sleeve down while grabbing the inner rod (most likely using a pliers or small vice grip while trying to unscrew the nut (which is round). There doesn't really seem like a way to do this without marring things which is why I'm asking for suggestions from those with more experience than me on these guns.

In the end not a huge deal as worst case I need to purchase a new guide rod/spring assembly but if I can't get this apart I won't be able to install the Wolff higher rate spring set.

Hope this helps with the 'why' I'm trying to do this vs. just buying a new set form Kahr.

Any tips from those that have 'been there and done it' would be greatly appreciated. Thanks again to all for feedback/suggestions.

[Glock23]

Is it not the outer spring that varies in strength?

[wyntrout]

It's generally advised here to leave the captured spring alone and just replace the outer spring. The guide rod nut is a "permanent" bond and some of us have had those come loose. Kahr replaces the whole assembly in that case. I've actually turned down a stainless steel nut and used it to make a spare assembly.

The red, permanent Loctite or similar thread locker compounds require considerable heat to defeat the bond... something like 500° and the proper tools to disassemble the parts while heated. You risk damaging the nut and the flange end of the recoil assembly with a vise or hand tools.

Wynn:)

[jocko]

wyns corrrect. leave ther inner sring alone, just change the outter andur good to go. ur kahr has a factory 18# spring by the way.

[ssmokn]

wyns corrrect. leave ther inner sring alone, just change the outter andur good to go. ur kahr has a factory 18# spring by the way.

Agree. The 19 was a typo on my part.

Wolff sells them as a set so I'm going to attempt disassembly. We shall see how it goes and I'll report back.

Worst case I have to buy a new OE recoil rod assembly.

I checked the Loctite 271 technical data sheet and you do need quite a bit of heat as was stated above... ' For disassembly: Heat parts up to 482°F (250°C) and separate parts while hot'.

Thanks.

[ssmokn]

OK, I figured let me give this a shot. I was able to get them apart with no problem.

I was planning on using heat but I end up not needing it.

Here is what I did. I slid the outer tube of the recoil down away from the end under spring tension. I then used a small vice grip (with the radius in the jaw -- not the straight jaw) around the inner rod. I adjusted the vicegrip so it would provide some bite without damaging the inner rod (have to do this buy judgement). I then did the same on the end nut (which is round and tapered edge) using a second small vice grip of the same type.

I was trying to turn to see if I had enough tension on both vice grips and I could see I was turning the nut so I just disassembled without heat (the entire proces took no more than 30 to 45 seconds and that was being careful).

The Wolff spring set should be here in a day or two. I'll cleanup the rod and threads so I'm ready to reassemble (with loctite red of course).

I'll snap a picture later of the pieces. Might help the next person that decides they would like to try this.

Cliff

[Bawanna]

Your mind is made up go forth and conquer.

I would one last time recommend aborting the mission and just replacing the outer spring, the inner don't do much.

I rather burn my fingers cooking a steak than a piece of metal I'll end up replacing anyhow.

[wyntrout]

Dang! Bawanna, he had it done before your reply! His mind WAS made up. Even if his replacement is fine, I wouldn't advise anyone going to that much trouble... it just isn't necessary. That's the thing about spring "kits", though, most feel compelled to use all of the springs. I would strenuously advise against buying one of Kahr's maintenance spring kits with ALL of the springs in the pistol. Most of those will NEVER fail and don't need replacement. Replacing them ALL usually brings more self-induced malfunctions since YOU"RE "FIXING SOMETHING THAT AIN'T BROKEN"!

Wynn:D

[Bawanna]

I'm thinking this is one of the rare instances where ssmokn's nut was not locked securely and he may have saved himself the grief of that nut flying off at the range and then having to replace the whole assembly.

I know I still check mine periodically with finger pressure only to make sure it's not spinning. If it ever does I'm gonna spot weld it.

Well done ssmokn, hope all goes back together well and the loctite holds things rock solid till the archeologist dig it up in a couple thousand years.

[wyntrout]

I guess I could have given a little advice... like leaving the gun whole and locking the slide back. If the nut is loose enough for hand tools and comes off easily, the nut can be removed and then disassemble the pistol, replace the inner spring, reassemble and lock the slide back for reassembly of the nut and guide rod... after thorough degreasing and cleaning the threads on both prior to applying the red threadlocker, of course.

Here's where I made my own recoil assembly guide rod nut:

http://www.kahrtalk.com/showthread.php?t=3934&highlight=make+flange+nut

http://i1134.photobucket.com/albums/m620/wyntrout/Kahr%20Recoil%20Spring%20Assembly%20Nut/IMG_0475.jpg

Wynn:)

[jocko]

plase beawarealso that ASOMETIMESwith btoh 20.5 springs in the assembly, for awhile it might not lock back on the lastround until the springs take their designed set. So just tha tone is aware ofit and doesn't piss his pants over sumpin wrong with the gun. Withdefense ammo is works perfect but some of this fml over thecountry range type ammo is not as powerful. Hand racking could also be alittle moredifficult at the git go but it will settle in OK, just be patient and not get excited if any of the above does occur...

I once was told by some who was more knowledeablethan I that the inner wolffs recoil spring is the smae as the original kahr spring, thatonly the outter is the more mpowerful one offered. Just sayin..:amflag:

[ssmokn]

OK, here is the picture I promised.... One of the recoil assembly and the other is the upper stripped as well.

I mean no disrespect to anyone but to me replacing the outer guide rod spring without the inner seems illogical. Many guns have one spring. These guns have to springs for a reason. They are both needed. Do they wear at the same rate? I have no idea. To me it doesn't seem appropriate to replace one spring and leave another that I would think is fatigued (how much -- I certainly don't know).

As always, use your own judgement and do what you feel is right. Personally I enjoy taking things apart and putting them back together and I like to do things properly (at least in my eyes -- again I really don't mean any disrespect)

While the upper is very Glock like indeed it's interesting that Kahr doesn't use a polymer bushing/sleeve inside the striker channel like Glock does.

Guide rod assembly.
https://lh5.googleusercontent.com/-1EWg9e_Z-YU/UZKJHTVFPoI/AAAAAAAANRM/QVeVUwdcrh8/w1152-h864-no/IMG_20130514_145319.jpg

Upper stripped / lower remains in tact.
https://lh4.googleusercontent.com/-ab0KnDtMxWw/UZKJHW8kkoI/AAAAAAAANRM/x5WU2afh-I8/w1152-h864-no/IMG_20130514_145310.jpg

[ssmokn]

I guess I could have given a little advice... like leaving the gun whole and locking the slide back. If the nut is loose enough for hand tools and comes off easily, the nut can be removed and then disassemble the pistol, replace the inner spring, reassemble and lock the slide back for reassembly of the nut and guide rod... after thorough degreasing and cleaning the threads on both prior to applying the red threadlocker, of course.

Here's where I made my own recoil assembly guide rod nut:

http://www.kahrtalk.com/showthread.php?t=3934&highlight=make+flange+nut

http://i1134.photobucket.com/albums/m620/wyntrout/Kahr%20Recoil%20Spring%20Assembly%20Nut/IMG_0475.jpg

Wynn:)

Doing it in the gun is a really good idea. I didn't think of that. It's like removing a front shock nut with the weight of the car on the shocks. Oh well.... It's done this time ;)

[ssmokn]

I'm thinking this is one of the rare instances where ssmokn's nut was not locked securely and he may have saved himself the grief of that nut flying off at the range and then having to replace the whole assembly.

I know I still check mine periodically with finger pressure only to make sure it's not spinning. If it ever does I'm gonna spot weld it.

Well done ssmokn, hope all goes back together well and the loctite holds things rock solid till the archeologist dig it up in a couple thousand years.

The spring retainer was indeed tight. No chance it was coming off. Keep in mind this is a small fastener and the vice grips (while the smallest one) gave me plenty of leverage.

I'll clean it well and use Loctite red for reassembly. I have no concerns with it coming loose. I've done this many times on other guns. This was just different enough that I was looking for a tip or two.

[jocko]

I am pretty sure my G19 has a nylone bushing sleeve in the striker channel. It is polymer sumpin in there,,

[ssmokn]

My brain and fingers are disconnected sometimes. I fixed my post. I meant to say that it was interesting KAHR doesn't use the polymer sleeve like Glock does in the striker channel.

[jocko]

much better, might be a patent thing maybe keepin it from happening. Kahrs striker is stainless and I think maybe nickel plated, never seen one rusted yet. so proabalby both work asdesigned. I think also glocks striker design internally is different, although IJO thereis alot of glock in kahrs slides. Just sayin.

ssmokin. on this forum one is only allowed so many miscues and then ur gone. I have been on here since the git go and have made over 52,500 miscues and I am still here, so I would say ur safe.

[Bawanna]

much better, might be a patent thing maybe keepin it from happening. Kahrs striker is stainless and I think maybe nickel plated, never seen one rusted yet. so proabalby both work asdesigned. I think also glocks striker design internally is different, although IJO thereis alot of glock in kahrs slides. Just sayin.

ssmokin. on this forum one is only allowed so many miscues and then ur gone. I have been on here since the git go and have made over 52,500 miscues and I am still here, so I would say ur safe.

Liar! It's only 52, 497 but the day ain't over yet.

[muggsy]

When your new springs arrive make sure to degrease the threads on the rod and nut with mineral spirits or something similar before you apply the locktite. It's down right embarrassing to go looking for that nut at the range. And don't go too heavy handed when you snug the nut down. Give that Locktite a chance to set up before you oil the RSA.

[jocko]

good advice muggs.

[ssmokn]

When your new springs arrive make sure to degrease the threads on the rod and nut with mineral spirits or something similar before you apply the locktite. It's down right embarrassing to go looking for that nut at the range. And don't go too heavy handed when you snug the nut down. Give that Locktite a chance to set up before you oil the RSA.

Good advice that I will follow. Thanks!

[wyntrout]

I didn't see your front extractor pin in the tray... the one that's slanted in the front. Maybe it's still in the extractor channel. I keep a straightened out paper clip to poke those things out.

The Glock's are different. I ordered a bunch of parts so that I would have spares for anything that goes sproing or falls off... like all of the pins and little springs and small plastic bits. I thought about the "water-resistant" plastic split rings, but just got the regular ones. I don't anticipate firing one in or just after coming out of the water... though I may get another boat in the future!:rolleyes: It ain't like I haven't fallen off the boat with my gun on before!:eek:

I can't wait until the next gun show! Things might be cheaper and more plentiful... at least SOME of the stuff!

Wynn:D

[ssmokn]

I didn't see your front extractor pin in the tray... the one that's slanted in the front. Maybe it's still in the extractor channel. I keep a straightened out paper clip to poke those things out.
Wynn:D

You have a really good eye. Last night I was checking out the exploded diagram and I noticed the front extractor pin was missing from my inventory (as soon as I looked at the picture I realized).

After I broke down the slide I was hosing out striker and extractor channels with some non-chlorinated brake clean over a trash barrel. I thought I heard a 'thud' like something fell out of the slide but then I thought it was just some trash shifting.

After looking at the diagram I got a magnet and starting sorting through the trash taking one piece out at a time and putting it into another barrel. I got lucky. After only removing a few pieces of trash there was a large piece of craft paper in the trash. I picked that up carefully and the magnet in my hand grabbed the front extractor pin.

I knew it had to be in the trash but I didn't think it was going to be that easy to find. That saved me $1.10 plus shipping but more importantly time lol.

I was surprised to see on the Kahr site that the tiny striker block spring cost $15.40. I think it was the most expensive spring in the gun.

Anyway, thanks for pointing out that pin. Had I not noticed last night you would have save me some time and trouble and I usually bring the trash to the dump on Wednesdays or Thursdays so it was a close call!

[wyntrout]

I'm glad you rescued that pin! I've had a bit of experience with those and now have spares of all of those parts for all of my Kahrs. The pins are cheap and some of the extractors and parts are interchangeable. I thought that little safety block spring was "only" $6.60 plus $5 shipping by itself! I bought several of the Glock equivalents... just for the Glocks, but cheaper than the Kahr springs.

I once was vacuuming the crud out of my slide and something fell on the floor... the extractor... and I assumed the lighter stuff was sucked into the vacuum. I got out the bag of really cruddy stuff and went through it with a strong magnet several times, but didn't find any pin or spring. I checked the extractor train channel and that stuff was still there!:rolleyes:

If you're ever getting anything from Kahr, try to order any stuff like that to cut down on shipping costs. You can throw on a lot of small parts for no extra postage costs.

I just ordered everything like that for our new Glocks, too. They have a lot of stuff that can work its way out or get lost! I'm prepared for a lot of stuff now!

Wynn:)