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09-21-2018, 07:47 PM #31
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09-25-2018, 07:58 AM #32
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I was doing some research on metal fractures and brittle and came across this University Physics educational PDF. Pretty easy to read, lots of pictures and seems to explain stuff well but a bit long. Check out the stuff on fracture and brittle.
https://www.google.com/url?sa=t&sour...B0xmoYUdUl2aif
This is just my interpretation of what's happening to the hangers.
I think a number of different factors cause the problem. I'm not an expert, but physics comes natrually to me.
- Hangers are probably stamped out and then cold formed to create the U-bend. The bend will have some brittleness because of cold forming.
- Poor welding teqniecs
- To hot a weld when trying to get penetration on thick high mass steel causing excess penetration and undercuts on hanger, smaller mass.
- Undercuts, etc. cause stress points
- The welding will cause more brittleness
- Cyclic and internal stress start a fracture
So bending and welding the hanger makes it brittle. Unfortunately the welding is at the bend that would already be a bit brittle. Then the force of the cyclic action is focused at the bend and weld. Kind of a perfect storm for a fracture.
That's my story and I'm stickin to it.Pat&Marlene Gyrogearloose - 2010 Itasca Meridian 34y - 6.7 w/Allison 6spd - Jeep Wrangler Rubicon - previous Reflection 303RLS
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09-25-2018, 09:56 AM #33
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09-25-2018, 10:08 AM #34
Pat and Rob - There has to be an additional factor involved. Why do most of the failures appear to be happening on the units with the 2" tubes installed?
Jim
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09-25-2018, 10:41 AM #35
Hi Jim . . . I have pondered this as well. The only thing that I can think of is that the weld is hotter because the wall of the 2" square tube has much less mass than the I beam would have, to draw the heat away. The other curiosity is why is it usually the right rear hanger that breaks first? If it is a fatigue break (and it sure looks like one) from bending the hanger repeatedly back and forth . . . all the hangers should be seeing this same motion. And the extension of this thought . . . why do I not see any indications of similar breaks starting on any of the other hangers?? The LCI tech who replaced my broken hanger examined the other ones and agreed that he could not see any indication of breaks.
RobCate & Rob
2015 Reflection 303RLS
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09-25-2018, 10:42 AM #36
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Pat&Marlene Gyrogearloose - 2010 Itasca Meridian 34y - 6.7 w/Allison 6spd - Jeep Wrangler Rubicon - previous Reflection 303RLS
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09-30-2018, 08:32 PM #37
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- Sep 2016
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- Crossville, TN
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I have an appt with Morryde for their independent suspension in early May on the way to the TN rally. After thinking about this some more, I think the bracket finally let loose at the national rally in Indiana. I remember hearing a bang as the trailer was auto-leveling, and even though I looked around, I did not know what to look for. I wish I had asked someone more experienced. I drove the unit several hundred miles after that, and it is just the grace of God that nothing let loose.
Now I have a question about the IS from Morryde. Does anyone know how much weight it adds to the tires? I currently have the 15 inch tires which will be going into their 3rd year next year. It seem like the right time to go to 16 inch tires. Just wondering if I have to because the IS weighs more than the "classic" suspension it is replacing? I have almost 400 lbs/tire excess capacity on the refrigerator side, and 750 lbs/tire on the door side.
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10-19-2018, 01:02 PM #38
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IDK the answer to the model issue Jim,
but what I CAN tell you is that anytime two welds are 2 inches apart it creates an "unstable" and "rocking cradle" situation.
There is just too much flex going on, in addition to the support of only an 8"
I- beam, which adds further vertical and twisting flex. Flex equals cracks.
When coupled with the weight disparity of the 303's opposing slides and their resulting suspension issues as well,
I find it incredible GD would even allow this frame mod to be implemented, no matter what the reason.
I'll wager the farm the majority of such fractures occur in this scenario.
A word to the wise...
Crawl under there every chance you get and visually inspect all welds, suspension and bolts. You should be greasing the wet bolts 2X a year anyways !!!
Take pics so you can review and document changes, at your leisure.
Michael
Sent from my SM-G930T using TapatalkPreviously known as mikgala
F-250 7.3 PSD Lariat Super Cab LB wt 152K - 25 row Ford tranny cooler, A&E Air Intake system, TS-6 high performance Super Chip, Air Ride airbags, Bilstein shocks
2017 Reflection 307 MKS 9,875 UVW / 12,995 GVWR / 1,605 Pin
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10-23-2020, 01:05 PM #39
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11-17-2020, 05:49 PM #40
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I found this on yootoob recently. I had planned on some re enforcing of the shackles anyway, but this video stressed the urgency to do something before I head out next spring. I am going to weld plates on all the shackles, then add a brace from one side to the other, then add a gusset from the shackle to the brace. I am hoping that will make things alot more solid.
https://www.youtube.com/watch?v=Bp5iRVPwYZg
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