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Post by legendts on Aug 16, 2019 13:50:49 GMT 10
Camped at the Maryborough Showgrounds a couple of days ago and during the early hours my wife was woken by a “bang”. Thought little of it until hooking up and noticed a rear off side tyre on the van flat. Changed wheels to the spare and moved on to the Gin Gin showgrounds after dropping the flat off at Tyrepower. Got set up and started looking at the bracket that has the spare and diesel heater tank mounted only to notice one of the U bolts had broken off. This U bolt and it’s mate are hard to eyeball as the spare pretty much covers them. The thing I didn’t like was instead of having a bottom plate with four holes for the two U bolts to spread the load and stresses they just had an individual plate for each. Luckily Kerry from Southern Star RV in Gin Gin was on site helping another couple and after a chat with him is going to fix the issue. He even suggested that the size of U bolt was too small for job and suggested a larger size together with a full plate to spread the load/stress. My real concern was that had the other U bolt snapped the 16” spare and diesel heater tank would have potentially killed or injured anyone following us. Scary to think about. The flat tyre was obviously a blessing in disguise but I’m annoyed I didn’t see the failure in Maryborough had it been broken then. I thought I was observant so maybe I need to be more so. I do regularly check bolt tightness but this just proves Murphy is just around the corner. In retrospect I’m wondering how I would see a failure like this in the future or how I may have seen this one beforehand. Photo of the snapped U bolt.  |
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Post by Mick Themungrel on Aug 16, 2019 13:59:31 GMT 10
Could have been nasty. Something else to keep a eye on.
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Post by Frank and Brenda on Aug 16, 2019 18:51:26 GMT 10
On our old van I found exactly the same break on a U bolt BUT it was one of the Ubolts holding the axle to the spring
The bolt was still doing it's job as the small bit on return was enough to "hang" on to the axle
Needless to say all 4 Ubolts were replaced
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Post by nsgnomad on Aug 16, 2019 21:14:35 GMT 10
Judging by the rust at the point of the break, it had been broken almost through for some time, and only just hanging on. No wonder it let go suddenly. Looking at the U bolt leg below the broken one, it appears to be out of alignment, not straight. Perhaps a welding fault, and the broken one was the same.
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Post by Muzz On Line on Aug 17, 2019 14:48:43 GMT 10
I have seen these U Bolts that have been welded sheered off due to over tightening. I think they generally should not be welded as it weakens the metal next to the weld, but i am not an engineer or metallurgist so don't have any facts as to why.
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Post by nsgnomad on Aug 17, 2019 21:25:35 GMT 10
I have seen these U Bolts that have been welded sheered off due to over tightening. I think they generally should not be welded as it weakens the metal next to the weld, but i am not an engineer or metallurgist so don't have any facts as to why. I had the same thoughts when I posted, but didn't mention it. |
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Post by legendts on Aug 18, 2019 8:37:19 GMT 10
I agree with all comments above, although when I had another close look at it I don’t believe it had been close to breaking for awhile but who knows. We had just come across to Maryborough (Qld) from Nanango on a very narrow and rough bitumen (?) road. I believe this is when it let go. As far as over tightening it, that is a possibility and I may have contributed to that as I had removed it a few years ago to weld the plate on for our diesel heater tank. Honestly can’t remember if the bottom plates were bent but I suspect they were as it’s not something (over tighteningj that I would generally do as I understand the consequences. I mostly use a tension wrench when tightening bolts on the van or elsewhere where warranted. Yes, another regular check to be aware of so I’ve added that to my pre trip trip checklist.
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Post by GerryP on Aug 18, 2019 8:56:46 GMT 10
Went out and checked ours and found it's set up differently. Instead of u bolts, ours has two plates welded to the upright, one front and one back so it slides down over the horizontal bumper bar. A single, large bolt through the plates, under the bar, clamps the plates and holds it all in place. It seems very firm with no movement at all.
I'd take a pic, but the van's backed up against the back wall in the shed.
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Post by legendts on Aug 24, 2019 19:47:23 GMT 10
Got it fixed now and it’s certainly more rigid. The previous set up you could get flex in the bracket but now there is none so I would think that it should be good for more than the 16 years the previous one managed.
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