Is this a frame crack?

[Scott'n'Wendy]

I took a peek at my frame above the suspension recently. Things look fine, except for maybe this 'kinda looks like the start of a crack?" maybe? I dunno. After I wiped it with a rag it looks less like one to me. Whatcha think? There is a virtually identical looking spot on the other side.

[AlexPeterson]

Looks like a paint crack. Pick at the paint with the corner of a razor blade to see if you can flake a few pieces off. It isn't in an apparently stressed location as it would be if it were right above a shackle mount, unless I'm not understanding the picture.

[ajg617]

I took a peek at my frame above the suspension recently. Things look fine, except for maybe this 'kinda looks like the start of a crack?" maybe? I dunno. After I wiped it with a rag it looks less like one to me. Whatcha think? There is a virtually identical looking spot on the other side.

I'd be more concerned with the rust line above the paint crack - that to me looks like the start of movement where water has entered and rusted the frame. I think the only way you can be sure is to sand the paint off the frame at that location to verify if there is a crack underneath. I have rust on my frame but it is blotchy not in a line. I think I can see three lines on your pic but the rust line to me is the most concerning.

[Scott'n'Wendy]

I think the only way you can be sure is to sand the paint off the frame at that location to verify if there is a crack underneath. I have rust on my frame but it is blotchy not in a line. I think I can see three lines on your pic but the rust line to me is the most concerning.

Ya, I want to wait until warmer temps so after I sand off the paint, I can spray some paint back on to protect it.
The whitish lines are from a screwdriver if those are the other lines you noticed?

[ajg617]

Ya, I want to wait until warmer temps so after I sand off the paint, I can spray some paint back on to protect it.
The whitish lines are from a screwdriver if those are the other lines you noticed?

Yep - that didn't bother me - looked like the paint was scratched.

[AlexPeterson]

Ya, I want to wait until warmer temps so after I sand off the paint, I can spray some paint back on to protect it.
The whitish lines are from a screwdriver if those are the other lines you noticed?

Do use a sharp blade to pick at the paint initially until you ascertain if it indeed a crack. Sanding tends to mask small cracks by rolling the metal edges into the crack.

[Cate&Rob]

If that is a crack, it is in the brace that LCI welds between the flange and the web of the I Beam chassis frame. This “reinforcement” has proven to be questionable at best because an I Beam web was never intended to take side loads in the first place. Actual frame cracks often occur in the I Beam web directly above this reinforcement. Keep an eye on that area. Since you have the 2x2 below the I Beam, this is a further reinforcement that many rigs do not have.

Rob

[Scott'n'Wendy]

If that is a crack, it is in the brace that LCI welds between the flange and the web of the I Beam chassis frame. This “reinforcement” has proven to be questionable at best because an I Beam web was never intended to take side loads in the first place. Actual frame cracks often occur in the I Beam web directly above this reinforcement. Keep an eye on that area. Since you have the 2x2 below the I Beam, this is a further reinforcement that many rigs do not have.

Rob

Funny you should mention that. There is a spot on the opposite side of the trailer that looks extremely similar....and the first thought that went through my head was "I wonder if there is a cross beam there?"

As to the 2x2 reinforcement...I think that is how they got away from the long 'perfect track' hangers? You probably know better than I.

[Scott'n'Wendy]

Do use a sharp blade to pick at the paint initially until you ascertain if it indeed a crack. Sanding tends to mask small cracks by rolling the metal edges into the crack.

I was kind of wondering about the proper method. I was thinking of a mini-grinder with a wire brush, but if I did that would obliterate signs of a crack. Unless there is some 'not too expensive' dye marker maybe?

[Cate&Rob]

Funny you should mention that. There is a spot on the opposite side of the trailer that looks extremely similar....and the first thought that went through my head was "I wonder if there is a cross beam there?"

As to the 2x2 reinforcement...I think that is how they got away from the long 'perfect track' hangers? You probably know better than I.

Yes . . . the “Correct Track” hangers also accomplished lifting the trailer frame approximately 2” for better clearance over recent production trucks that are taller than they used to be. The 2x2 (some call it a “crush tube” but I am not sure why) came along with the later build shorter hangers.

Rob

[Scott'n'Wendy]

The 2x2 (some call it a “crush tube” but I am not sure why)

Rob

Ha...Not exactly a confidence inspiring nickname...

[Yoda]

Yes . . . the “Correct Track” hangers also accomplished lifting the trailer frame approximately 2” for better clearance over recent production trucks that are taller than they used to be. The 2x2 (some call it a “crush tube” but I am not sure why) came along with the later build shorter hangers.

Rob

Scott'n'Wendy

I agree with Rob and the others - its a paint crack. However I would keep an eye on the area around the improperly placed gusset plate that I think I see in the upper right corner that transfers the bending load of the flange to the frame web. On my 220RK that where the cracks started. Also check where cross members are welded inside to the web (like tank supports) - you can see signs on the web where the welding was done inside. Look at my 220RK frame crack thread to see examples.

I had trouble figuring out that there were 2-2x2 sub frames there until Rob mentioned it. Makes the stress on the frame web even worse. Question - did Lippert add any welded cross beams in that area?

So for now relax.

Keith

BTW Power weld makes a spray crack checker https://www.zoro.com/powerweld-penet...=&gad_source=1 Be careful this is just for the penetrate can - you need the cleaner and developer too..
Magnaflux has a similar product https://www.grainger.com/product/3WU...ce=1&gclsrc=ds again you need the cleaner and developer too.

[Scott'n'Wendy]

Scott'n'Wendy

IHowever I would keep an eye on the area around the improperly placed gusset plate that I think I see in the upper right corner that transfers the bending load of the flange to the frame web.

That is the plate around the opening for the slide

[Yoda]

That is the plate around the opening for the slide

Say What? Can you post a wider view showing the springs and hanger's set up? I' curious of what reinforcement was done to support the double sub frame.
Keith

[Scott'n'Wendy]

Say What? Can you post a wider view showing the springs and hanger's set up? I' curious of what reinforcement was done to support the double sub frame.
Keith

I can take another pic tomorrow...little bit dark now...but there is no extra reinforcement. Just a 2x2 box tube to raise the trailer a bit.