Fractured chassis 2010 Escape 19' just behind the front jack on driver's side.

[RWD]

The Escape 19 is tucked away at the repair shop till Monday. I will send more pictures when I can visit it.
Thank you all for participating on this forum.
RWD

[Brian B-P]

Originally Posted by Ron in BC

That puzzles me also. I'd expect that the crack would have propagated right through the center of the bolt hole.

It appears that the washer and nut may have been tacked on to prevent them from loosening and that the crack is immediately behind them.

I had not zoomed in on the photos before, but now I see what you mean - it is clearly beside the washer, not involving the bolt hole.

The crack is right at the edge of what might be a tack weld bead. Welding this - especially on a frame - seems like a strange choice, compared to just using a self-locking nut (although the self-locking nut would require someone to hold a wrench on the bolt head inside the trailer). Maybe the apparent tack weld is just a glob of whatever the red stuff is?

It does look like a brittle break, rather than a tear. How hard are these frames? I vaguely recall a comment a long time ago about the alloy and heat treatment of the frame making them relatively hard... which means strong, but potentially brittle and sensitive to issues due to welding and drilling. The vast majority have no problems at all and have worked very well, but something went wrong in this case.

[RWD]

New photos
Others to follow.
From,
RWD

[Jim Bennett]

Thanks for the added photos, that tells a lot more. For starters, I was confused about how the stabilizers looked and mounted, but see that they are a different type than what I had on my 19.

That break is definitely behind the weld, and is most likely at, or near, the back of the inside mending plate. I too would have though it would have migrated through the bolt hole though.

Just glad to see you caught it before it became a catastrophic issue. This is a good reminder for people to actually check their frames once in a while. I do this with my construction trailers, and did find a cracked frame on one of them a few years ago.

[thoer]

Looks like this cracked at a completely different point than the weld addressed in the recall. Is there a frame cross member welded at the front edge of that crack? Also, is that a weld bead on the back of the jack's mounting plate, directly next to the front of the crack?

[techfan]

Just curious... Were those stabilizers standard on the 19 in 2010? I have never seen an Escape with those.

[Rossue]

Our 2010 17B had those and has been referred to here in the past as a 'mis-shipment" that ETI had for a short time and used.

[thoer]

Originally Posted by techfan

Just curious... Were those stabilizers standard on the 19 in 2010? I have never seen an Escape with those.

Tim - they are on many 2010's including our 17B. When we picked up ours Reace said that these had been shipped by mistake to ETI rather than the one leg models and he decided rather than ship them back to go ahead and put them on - giving us a more substantial model at no extra cost. Then for a while he would put them on as an option, but finally decided that he was afraid people would be too tempted to use them improperly to jack up the trailer rather then just minor leveling and stabilization as they are intended. Makes me wonder a bit if anything regarding these heavier duty jacks that could be a contributing cause here. But the last I heard, he was concerned that someone might be able to twist their frame out of alignment, not crack it.

[techfan]

Originally Posted by thoer

Tim - they are on many 2010's including our 17B. When we picked up ours Reace said that these had been shipped by mistake to ETI rather than the one leg models and he decided rather than ship them back to go ahead and put them on - giving us a more substantial model at no extra cost. Then for a while he would put them on as an option, but finally decided that he was afraid people would be too tempted to use them improperly to jack up the trailer rather then just minor leveling and stabilization as they are intended. Makes me wonder a bit if anything regarding these heavier duty jacks that could be a contributing cause here.

Ahh... Kind of what I was thinking. Those jacks can generate a lot of torque and if cranked hard the break would be behind it because of the trailer weight. Also one more reason why all frames needed to be 4". Maybe one of you engineers could weigh in here but I would be suspect of the jacks as a contributing cause.

[Klem]

This is a WAG but could the Jack have been hit from the front which pinched the the frame and it worked into this tear? Notice jack on the other side appears tilted rearward.

Towed nose too high causing the back end frame stress to concentrate at the bolted location? The frame nose is tight the aft section is working this crack?

[thoer]

Originally Posted by techfan

Ahh... Kind of what I was thinking. Those jacks can generate a lot of torque and if cranked hard the break would be behind it because of the trailer weight. Also one more reason why all frames needed to be 4". Maybe one of you engineers could weigh in here but I would be suspect of the jacks as a contributing cause.

Tim - I went down and looked to verify what I remembered - but on my 17B, the jack mounting plate straddles the weld joints for the cross member so it shouldn't put extra stress on the welds there anyway.

That's behind my curiosity on where the cross member is in relation to this crack. My old welder self looks at this and it looks like cracks I've seen on the edges of welds - cold cracks I think is what they are called. If the cross member is just on the front side of that crack that would be my guess (and nothing but a guess - I never finished my engineering degree program) As Brian mentioned harder steel alloys be can more prone to brittleness when welded. The more powerful jack could have been a contributing factor if there was brittleness there. If there is no cross member there, than I supposed it is possible the weld of the jack mounting plate right at the edge of the crack could have been the starting point.

Or I could just be completely wrong - won't be the first time!!

Whatever the cause, I second Ron's suggestion of welding completely around the tube.

[David H]

Originally Posted by thoer

Tim - I went down and looked to verify what I remembered - but on my 17B, the jack mounting plate straddles the weld joints for the cross member so it shouldn't put extra stress on the welds there anyway.

That's behind my curiosity on where the cross member is in relation to this crack. My old welder self looks at this and it looks like cracks I've seen on the edges of welds - cold cracks I think is what they are called. If the cross member is just on the front side of that crack that would be my guess (and nothing but a guess - I never finished my engineering degree program) As Brian mentioned harder steel alloys be can more prone to brittleness when welded. The more powerful jack could have been a contributing factor if there was brittleness there. If there is no cross member there, than I supposed it is possible the weld of the jack mounting plate right at the edge of the crack could have been the starting point.

Or I could just be completely wrong - won't be the first time!!

Whatever the cause, I second Ron's suggestion of welding completely around the tube.

I agree. I believe these frames are T1 alloy steel (ASTM A-514) which has a very high yield strength at 100 ksi and is quiet difficult to weld. Crack is likely as you say a cold crack (hydrogen crack) at the toe of the tack weld and these are usually a result of a lack of pre heat prior to welding. So likely been there since day one and propagated across the bottom flange of the C channel then up the web over a long period of time as a result of the low cycle high stress loading when jacking (minor)combined with the considerable dynamic loads imposed during towing (major).

As Jim points out its a heads up that all trailer owners should carefully inspect there trailer frame annually as part of there ongoing maintenance.

[Ron in BC]

propagated across the bottom flange of the C channel then up the web over a l[/QUOTE]

Is it channel? The close-up photo in post #23 looks like it but I thought it would be rectangular tube. Maybe the fracture isn't completely visible. Or did ETI go from 3" channel to 4" tube?

Ron

[thoer]

Is it channel? The close-up photo in post #23 looks like it but I thought it would be rectangular tube. Maybe the fracture isn't completely visible. Or did ETI go from 3" channel to 4" tube?

Ron

Aren't all the frames rectangular tubes? My 2010 17B is and all others I've seen have been.

[Parker]

Thinking as I go here, but it seems like there would be more stress on the frame when it's supported by the ball as in towing, since that's a longer lever arm producing a greater moment in the area of the crack. Unless the front jacks were used as a sole source of support (no tongue jack) and this particular side was regularly cranked down tighter, supporting most of the trailer weight forward of the wheels. I'm falling into the camp of it being a metallurgical (or welding) issue, assuming there there wasn't a lot of extra weight added to the tongue while towing.

[thoer]

Parker that makes a lot of sense to me. I've always struggled with the concept of even the heavy duty jacks being able to actually do damage to the frame, when as you say, the lever arm compounding the tongue weight when towing should be capable of putting much greater stresses on the frame. But maybe it is that the frame is specifically designed to withstand the forces from the tongue and the jacks could put on an entirely different stress. I think I need a beer now before I hurt these old brain cells.

[Parker]

Let's see now....start drawing moment diagrams, consulting stress/strain curves...... or have a beer. Hmmm...

[thoer]

Originally Posted by Parker

Let's see now....start drawing moment diagrams, consulting stress/strain curves...... or have a beer. Hmmm...

And lets hope RWD gets it fixed soon and heads off on that trip to Florida.

[Jim Bennett]

Originally Posted by Parker

Let's see now....start drawing moment diagrams, consulting stress/strain curves...... or have a beer. Hmmm...

Wow, I can't believe you are struggling with that decision. I say beer for the win.

I remember studying bending moments, and understand very well how the are derived, but boy o' boy, if I had to calculate them now, I would be driven to drinking too.

I don't believe that the jack loading has anything to do with the crack either.

[Jubal]

The fracture and seperation occured on the frame of a 2010, 19 that has less weight on the tongue than the last 19' production trailers with a 3" frame supporting a storage box with a 100 lb capacity, 2 batteries, and two LP tanks.
Note the rock shield and stinky slinky storage tube on the tongue in one of the photos.