Stuck operating rod

[Profiteer61]

I'm sure if I read enough I will find this topic. I've read many suggestions on the net.
I can't remove the handguard due to the operating rod being jammed. I fired 2 rounds and they ejected correctly.
Pounding with a drift did nothing. I don't want to peen the hole.
Maybe unpin the gas block and slide it forward?

[Boris Badinov]

Op rod looks like its in.the right spot. There may be a different issue with the gas / recoil.

You've got the lever too high to remove the handguard.

Lower the lever to halfway to remove the handguard. Then cover the forward op rod hole before you lift the lever further to remove the op rod. Otherwise itll go flying and you'll be on your kands and knees looking for both the rod and the spring.

[Profiteer61]

The lever is hanging there. It doesn't matter where you turn it. The longer rod in the handguard isn't retracting. That's why the handguard won't lift out.


 
 

[Phosphorus32]

The takedown lever needs to be in the position shown below:




The takedown lever shaft has a flat edge that allows the handguard and piston assembly to be lifted up. If you over-rotate forward it's designed to prevent lifting that assembly, because if you were able to the spring loaded operating rod found in the rear sight base would launch like an under-powered TOW missile:

[running-man]

Let's get our nomenclature down so we are all on the same page:

Op(erating) rod: the short ~2" long rod that resides under the rear sight. This rod has an integral return spring.  When the gas tube is out of the gun, the cam on the takedown lever holds it in place. Over rotate the cam with the gas tube out and you get to go looking for the op rod and the spring on the floor on the other side of the room.  Note that an SKS carbine will not cycle without an op rod.

Gas piston: sometimes called a piston rod. Long 10" rod that resides in the gas tube. This piston has no integral spring and instead relies on the return of the op rod to force it back into position after the carbine has cycled. The gas piston only was designed to travel about 3/4" to 1" within the gas tube. Often the tolerances are such that when it is allowed to move more than that it will bind up.

Normally when a jammed gas tube occurs, the gun was fired without the op rod in place and the gas piston is forced into an extreme position beyond 1" where it binds up. Even worse is that the end is out of the gas tube and well within the cavity under the rear sight (where the op rod should be). A bound up gas piston in this state needs to be tapped out with a small diameter dowel or other rod.

If what we see in your photo is the end of the op rod (which I assume it is as I've never seen a gas piston driven out a full 2" like that before) then the above physically cannot occur and your take down lever is indeed causing you grief.

Try moving the takedown lever to the second detent and wiggling the gas tube; it should pop right out. 

[Greatguns]

Raise your rear sight leaf so you can see into the hole underneath. It's possible the spring is broken and the gas piston has traveled just enough rearward to keep the gas tube from being removable. The extension rod (Op rod) actually looks a hair exposed which could be an indicator of that. Try using a flat punch and tapping the rod forward to see if it relieves the piston enough to remove the gas tube.

[Boris Badinov]

If the piston is in fact crud-stuck somehow, you'll need to get some penetrating oil into the the tube.

The vent holes on the side of the gas tube are a good place to start.

Might  also try turn the rifle upside down and at a low angle putting penetrating oil down the muzzle to get the oil into the gas porting hole in the top of the barrel.

Let ot soak overnight. Then you can tap the tube with the handle of a screwdriver to coax free a  crud-stuck piston.

[Boris Badinov]

It should be pointed out that a hammer and punch on the op rod will not move the main piston unless the handguard removal lever is in the full open position.

When the pistion and op rod are in their places and functional, they are touching. The two pistons funtion as one.

https://youtu.be/lg0wODNQK10?t=30&si=qpOepf7fRDvcXT1S


If there was a failure to cycle, given the curcumstaces in this instance, there may be gas leak in the main piston tube beneath the wood of the handguard.

Theres an easy way to check for this with rubbing alcohol if you can get the handguard off.

[Profiteer61]

Ok. I dont know why I posted that picture. The op. rod is fine. It is the long piston rod that is jammed out about 1/4". I was able to pry the handguard/gas tube up and out. I made a short (2 minute) video comparing two gas tube piston rods. One slides freely and comes out 2 inches, the other gets jammed sticking out 1/4" and has to be forced back in. I don't have a way to host a video, but the gas tube piston rod seems to be really crapped up.
I'm going to hone it out so it too will be "free".

[Boris Badinov]

Ok. I dont know why I posted that picture. The op. rod is fine. It is the long piston rod that is jammed out about 1/4". I was able to pry the handguard/gas tube up and out. I made a short (2 minute) video comparing two gas tube piston rods. One slides freely and comes out 2 inches, the other gets jammed sticking out 1/4" and has to be forced back in. I don't have a way to host a video, but the gas tube piston rod seems to be really crapped up.
I'm going to hone it out so it too will be "free".

Dont touch the sides of the piston head. If the sides are corroded, youll need to get a new piston. The sks designed with generous operating tolerances
The diameter of the piston is not one of them. It only takes a minimal loss of surface on the sides of the pistion to weaken recoil leading to failures to feed, and eject.

Also be advised  that the piston only travels less than ome-half of an inch when functioning. Any corrosion in the gas tube beyond that first half inch isnt goimg to alter function.

[Boris Badinov]

There is a simple function test for the gas piston:

With hand guard removed, and piston installed. Set piston head flush with the opening of the gas tube, cover the opening entirely with your thumb. With the opeing covered. turn the handguard perpendicular to the ground and let the piston fall with gravity.


A properly functioning piston will fall slowly in the tube, and you should feel light suction on the pad of your thumb. A marred pistonn should funnction prefectly if it can pass this simple gravity test.

[Profiteer61]

Got it! Thanks for the great info.

[Profiteer61]

Raise your rear sight leaf so you can see into the hole underneath.

There is no hole under the rear sight leaf. Sorry.