Problems with YHM LW FF rail (loosened up) and end-cap (touching the gas tube)

AR-15 » Rifles, Uppers, Lowers, Barrels, and more

AR Sponsor:

[ARCHIVED THREAD] - Problems with YHM LW FF rail (loosened up) and end-cap (touching the gas tube)

Posted: 8/4/2005 12:09:10 PM EDT

My YHM LW FF rail has loosened up and the end-cap is touching the bottom part of the gas tube. having
My DPMS AR15 multi-tool doesn't fit on the YHM jam nut, so here's what I'm thinking:
1) order the special YHM wrench and re-tighten the forearm-jam nut
2) drill a small hole in the jam nut and another one in the forearm itself to put set screws that will really "lock" both pieces on the barrel nut.
Has anybody done this before ?

Now, for the end-cap hole that touches the gas tube (which is inserted in the YHM flip-up FSB w/o bayo lug), I simply want to cut the "offending" portion with a Dremel... which implies i'll have to remove the FH, FSB, gas tube, .... I wanna keep this cap, 'cause I prefer the look of my carbine with it.

Posted: 8/4/2005 1:47:42 PM EDT

[#1]

I hate to say it but whoever assembled it did a very poor job of doing so. At this point I would recommend disassembling the upper and make sure it goes back together right this time, you can do this yourself with limited tools. After you make sure the barrel is tight I would clean the exterior threads under the forearm portion & the jam nut and use 242 Loctite (blue) during reassembly, I would use 222 or a very small application of 242 on the ventilated endcap. The YHM wrench would also help in properly tightening the jam nut.

Posted: 8/4/2005 2:12:21 PM EDT

[#2]

Quoted:
2) drill a small hole in the jam nut and another one in the forearm itself to put set screws that will really "lock" both pieces on the barrel nut.

I had two tubes do the same. If I were forced to own a YHM railed FF tube again, that is exactly what I would do. That way you would have a mechanical means of keeping that tube tight, rather than relying solely on the lock nut friction. Done carefully and diligently, it would likely look like it belonged there. Good luck.

Posted: 8/4/2005 4:46:36 PM EDT

[#3]

Quoted:
Quoted:
2) drill a small hole in the jam nut and another one in the forearm itself to put set screws that will really "lock" both pieces on the barrel nut.

I had two tubes do the same. If I were forced to own a YHM railed FF tube again, that is exactly what I would do. That way you would have a mechanical means of keeping that tube tight, rather than relying solely on the lock nut friction. Done carefully and diligently, it would likely look like it belonged there. Good luck.

I have seen this issue as well.

C4

Posted: 8/4/2005 5:44:40 PM EDT

[#4]

We use red locktite on the nut, dremel the offending hole would also be a safety measure but shouldn't need it, let me know if I can help, I have a YHM wrench here if you dont want to buy we can ship to you for a 3-4 bucks priority mail shipping. Course if you dont return it I send my hit-woman Krista out to recover

Robert
309-534-8175
[email protected]

Posted: 8/5/2005 4:32:45 AM EDT

[#5]

i have never had any problems with the ones i have.

never used any loctite either.

Posted: 8/5/2005 1:56:40 PM EDT

[#6]

This is the way I install YHM FF rails...

After securing the receiver in a vise (protected of course), use red loctite on the threads, use an A3 carry handle to index the FF to the receiver and a flat blade screwdriver and hammer to tighten the jam nut... Easy as 123

Just a note: Be sure not to run the FF down to close to the receiver, it may prevent the upper from being able to align properly with the lower... (The jam nut will make contact with the lower receiver near the pivot pin)

Posted: 8/5/2005 2:15:08 PM EDT

[#7]

Quoted:
This is the way I install YHM FF rails...

After securing the receiver in a vise (protected of course), use red loctite on the threads, use an A3 carry handle to index the FF to the receiver and a flat blade screwdriver and hammer to tighten the jam nut... Easy as 123

Just a note: Be sure not to run the FF down to close to the receiver, it may prevent the upper from being able to align properly with the lower... (The jam nut will make contact with the lower receiver near the pivot pin)

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

Posted: 8/5/2005 2:45:19 PM EDT

[#8]

Quoted:
Quoted:
This is the way I install YHM FF rails...

After securing the receiver in a vise (protected of course), use red loctite on the threads, use an A3 carry handle to index the FF to the receiver and a flat blade screwdriver and hammer to tighten the jam nut... Easy as 123

Just a note: Be sure not to run the FF down to close to the receiver, it may prevent the upper from being able to align properly with the lower... (The jam nut will make contact with the lower receiver near the pivot pin)

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

Throw it in the oven and heat it up? (edited to add the question mark)

Posted: 8/5/2005 2:47:42 PM EDT

[#9]

Quoted:

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

I use heat to remove them, its realy not a big deal... I read alot of post here about how hard red is to remove... Heat is the way to do it...

Edited to add: I use a pencil tip soldering iron for small set screws, soldering gun for larger set screws and propane for the bigger stuff... It works every time

Posted: 8/5/2005 5:29:30 PM EDT

[#10]

Quoted:
Quoted:

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

I use heat to remove them, its realy not a big deal... I read alot of post here about how hard red is to remove... Heat is the way to do it...

Edited to add: I use a pencil tip soldering iron for small set screws, soldering gun for larger set screws and propane for the bigger stuff... It works every time

I knew the answer to my own question and just wanted to make sure that other folks realized that you have to use a blow torch to loosen up red loc tite. The other issue is that you CAN get galling when you torque threads onto each other and use loc tite.

C4

Posted: 8/5/2005 5:35:42 PM EDT

[#11]

I would loc-tite just about everything I put on my gun anyway.

Posted: 8/5/2005 5:52:55 PM EDT

[#12]

Quoted:
I would loc-tite just about everything I put on my gun anyway.

I do as well, but use blue loc tite.

C4

Posted: 8/5/2005 6:19:22 PM EDT

[#13]

Quoted:
Quoted:
Quoted:

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

I use heat to remove them, its realy not a big deal... I read alot of post here about how hard red is to remove... Heat is the way to do it...

Edited to add: I use a pencil tip soldering iron for small set screws, soldering gun for larger set screws and propane for the bigger stuff... It works every time

I knew the answer to my own question and just wanted to make sure that other folks realized that you have to use a blow torch to loosen up red loc tite. The other issue is that you CAN get galling when you torque threads onto each other and use loc tite.

C4

I guess that was a test question? Any way, a "blow torch" is nothing but another tool... And about the galling, that could happen with any threaded part that is over torqued, even if they dont have loctite on them...

Posted: 8/5/2005 6:29:29 PM EDT

[#14]

Quoted:
Quoted:
Quoted:
Quoted:

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

I use heat to remove them, its realy not a big deal... I read alot of post here about how hard red is to remove... Heat is the way to do it...

Edited to add: I use a pencil tip soldering iron for small set screws, soldering gun for larger set screws and propane for the bigger stuff... It works every time

I knew the answer to my own question and just wanted to make sure that other folks realized that you have to use a blow torch to loosen up red loc tite. The other issue is that you CAN get galling when you torque threads onto each other and use loc tite.

C4

I guess that was a test question? Any way, a "blow torch" is nothing but another tool... And about the galling, that could happen with any threaded part that is over torqued, even if they dont have loctite on them...

Galling can occur anytime you torque threads. This is why you use a high temp moly grease on your barrel nut. Loc tite just adds to the possibility of galling making it a no joy to me.

C4

Posted: 8/5/2005 6:36:45 PM EDT

[#15]

Quoted:
Quoted:
I would loc-tite just about everything I put on my gun anyway.

I do as well, but use blue loc tite.

C4

I've ordered the YHM wrench and will certainly put a bit of blue loctite.

Posted: 8/5/2005 7:00:15 PM EDT

[#16]

Quoted:
Quoted:
I would loc-tite just about everything I put on my gun anyway.

I do as well, but use blue loc tite.

C4

I used to, but have heard too many tales of things coming loose. The most notorious are front sights on Glocks.

Posted: 8/6/2005 5:55:43 AM EDT

[#17]

Quoted:
Quoted:
Quoted:
Quoted:
Quoted:

I have a question, what happens when you want to remove said rail (with the red loc tite on them)?

C4

I use heat to remove them, its realy not a big deal... I read alot of post here about how hard red is to remove... Heat is the way to do it...

Edited to add: I use a pencil tip soldering iron for small set screws, soldering gun for larger set screws and propane for the bigger stuff... It works every time

I knew the answer to my own question and just wanted to make sure that other folks realized that you have to use a blow torch to loosen up red loc tite. The other issue is that you CAN get galling when you torque threads onto each other and use loc tite.

C4

I guess that was a test question? Any way, a "blow torch" is nothing but another tool... And about the galling, that could happen with any threaded part that is over torqued, even if they dont have loctite on them...

Galling can occur anytime you torque threads. This is why you use a high temp moly grease on your barrel nut. Loc tite just adds to the possibility of galling making it a no joy to me.

C4

Moly grease also helps in preventing the barrel extension from rotating while tightening the barrel nut, preventing the alignment pin from bending...

Posted: 8/6/2005 2:53:58 PM EDT

[#18]

Quoted:
... use an A3 carry handle to index the FF to the receiver and a flat blade screwdriver and hammer to tighten the jam nut...

I did that with an ASA one-piece scope mount and a flat-blade screwdriver ... on my kitchen counter hinking.gif
It surely tightened up the YHM FF rail, but it's a temporary solution.

The YHM wrench and DPMS upper receiver vise block are on their way

Posted: 8/8/2005 7:51:01 AM EDT

[#19]

The YHM wrench is a great tool...you can use it on a regular barrel nut, and it's much easier than a regular amorer's wrench. It's essential if you have jam nuts that need to be tightened. Your YHM fore ends will not come lose if you get the ram nut good and tight.

Posted: 8/8/2005 8:01:42 AM EDT

[#20]

those F*CK!NG YHM threads are too fine pitch-wise. that friggin locking ring and rail will rotate all day against one another...

[ARCHIVED THREAD] - Problems with YHM LW FF rail (loosened up) and end-cap (touching the gas tube)

AR-15 » Rifles, Uppers, Lowers, Barrels, and more

AR Sponsor:

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us