Garand disassembly issue

[Char-Gar]

Today I decided to remove the gas cylinder value screw for the first time while cleaning. There is no way I can budge that things with just a proper fitting screwdriver and hand power. I know you have to push in on the spring while turning, but it won't budge. I am reluctant to rig up a breaker bar and really horse it out for fear I will twist something.

What am I doing wrong? Any secrets here?

[garandsrus]

Chargar,

Here is a tool that can help: http://www.brownells.com/.aspx/pid=16744/Product/ARMORY_M1_GARAND_GAS_CYLINDER_WRENCH

You can find it more cheaply at Fulton Armory. It helps to keep anything from getting twisted. The nut can be stubborn some times. The Garand combo tool gives you some leverage to break the nut loose.

John

[TNsailorman]

When I run into a stuck screw(usually fine rust) I soak it with Kroil for about 3 or 4 hours. Then I take a proper fitting screwdriver and fitting the blade carefully in the slot, I tap it two or three times with moderate force(depending on the size of the screw). Most of the time it will then back out with some heavy force applied to the screwdriver. Once in awhile it will take 2 or more soakings before it comes free. James

[Pirate69]

Chargar,
A 1/4" socket drive will work well to remove the plug. However, you need to support the gas cylinder to make sure it does not twist on the barrel. That is what the wrench above is for. You can also support it in a vise with just enough pressure to hold it. Sometimes the plugs were installed much to tight and they are difficult to remove. I use anti-seize to properly install the plug and aid in its removal when I need to. Some people feel that the anti-seize causes the plug to come loose during firing. If the plug has proper tension, that is not the case.

The plug is basically a bolt. It is widely believed that vibration causes bolt loosening. By far the most frequent cause of loosening is side sliding of the nut or bolt head relative to the joint, resulting in relative motion occurring in the threads. If this does not occur, then the bolts will not loosen, even if the joint is subjected to severe vibration. The key is to get the necessary clamp force so that the plug does not have the minute movement in the threads. The clamp force is a function of the torque that is placed on the plug, the torque coefficient and the diameter of the plug. If you know the torque coefficient, the desired clamp load and the diameter of the plug, you can calculate the required torque using the following equation:

T=K x F x D.

Anti-seize can be used to develop greater clamp load for the same torque compared to an unlubricated plug. It does this by presenting a different torque coefficient as compared to an unlubricated plug. This actually makes it easier to obtain the desired clamp force and at the same time protect the treads.

As an example, I found a reference to a ½” bolt (solvent cleaned, not lubricated) with a torgue coefficient of approximately 0.27. Looking at the spec sheet for Loctite anti-seize, I find a torgue coefficient of approximately 0.11. The plug is ½” and is basically a bolt. I ran a torgue calculator program using the thread depth and thread count for the plug using the unlubed and anti-seized coefficients. The results are presented below. It was determined that a tension of 4474 pounds was recommended for a bolt of this design. In order to achieve the 4474 pounds of tension, it is recommended that 52.6 ft-lb be used for the unlubricated bolt and 21.4 ft-lb of torque be used for the anti-seized bolt. This is 60% less torgue to get the same tension. The friction eats up a lot of the torque.

Re-installing, with anti-seize and a large flat screwdriver, you may be able to get the necessary tension by hand. Without it, you may not and the plug could come lose. I use it to ensure greater tension and at the same time, protect the threads. Just my preference.

Unlubed bolt
Major Bolt Diameter: 0.500 in
Bolt Thread Pitch: 28
Bolt Proof Strength: 44000 psi
Recepticle Length: 0.2 in
Recepticle Strength: 140000 psi
Applied Tensile Load: 0 lb
k Factor: 0.27

Recommended Torque
631 in-lb
(52.59 ft-lb)
(71.31 N-m)
Resultant Tension:4674 lb
Maximum Torque
841.4 in-lb
(70.11 ft-lb)
(95.07 N-m)
Resultant Tension:6232 lb

Anti-seized bolt
Major Bolt Diameter: 0.500 in
Bolt Thread Pitch: 28
Bolt Proof Strength: 44000 psi
Recepticle Length: 0.2 in
Recepticle Strength: 140000 psi
Applied Tensile Load: 0 lb
k Factor: 0.11

Recommended Torque
257.08 in-lb
(21.424 ft-lb)
(29.05 N-m)
Resultant Tension:4674 lb
Maximum Torque
342.8 in-lb
(28.565 ft-lb)
(38.73 N-m)
Resultant Tension:6232 lb

[Lead Fred]

Anti-Seize is good stuff.
I always use it on my M1 plug

[Multigunner]

You might try heating the gas tube a bit, not too much just too hot to touch.
Powder residue may have migrated into the threads and set up hard.
Also a previous owner may have used RTV sealant. Some types of RTV sealants were used on Garands to basically glue loose parts solid. Some of these sealants are very heat resistent and wooden parts have been damaged trying to remove them.
I think the Navy first tried these sealants on worn range rifles. Been a long time since I looked into that though so I'm going by an often faulty memory.

PS don't know if Koil would have any effect since these cylinders and plugs shouldn't rust.

[Char-Gar]

Thanks for all the advice. My rifle is a 5-65 RRAD rebuild and is about 99.5% new/as rebuilt.

[mroliver77]

Soak it well. Support gas cylinder(a must as spline fit can be loosened if excessive torque is applied to gas cylinder). Use a good fitting driver. A 1/4" ratchet with screw driver bit will help. Use patience. The spring has nothing to do with loosening it. It is overload valve.
J
Oh ya, show me pics of yours and I will show you pics of mine. ;)

[dominicfortune00]

Actually, the spring activated poppet valve in the gas cylinder plug is for disabling the gas system while launching rifle grenades.

[shotman]

one thing I found on VFW guns that were never taken care of
Take op rod out and put Kroil IN the gas cyl take patches or paper towel and stuff in the gas tube put op rod back in and let sit over night bet you can remove easy