Not trying to insinuate that at all, the thought never crossed my mind, it would have been a lonely journey.
I was trying to reinforce the probability.
Everyone saying virtually the same thing - it was your fault. LSL that came on for views on the subject: no no, it can’t be.
So how did it go, LSL?
The silence is deafening.
wasn’t there someone on here last year that had been invited for tea and biscuits and was going to sue the government the queen and little tim’s dog
Hello hello and wasn’t no meeting they postponed due to accident caused by other driver and the manager he couldn’t attend on this meeting.
So if you have any suggestions except blaming me, I will be grateful if not do not comment then because you’re wasting your time.
I only kindly ask for situations when the trailer can detach himself without bling anyone just some materials movies anything could have. Help
This happened to me years ago
I did the the very same thing, i hooked up done the chuck 2 times finished the rest and pulled away
I drove a mile in a straight line then made a right turn, then a further couple yards made a left turn, as the turn was complete and i was in a straight line i was changing gear to continue straight when the big bang came, sparks everywhere it came clean off the 5th wheel
Nobody could prove the truck was faulty
It was only weeks after that the same thing happened to the same trailer different truck different driver
It was the pin on the trailer
Stuff happens and it’s a hard one to prove if no evidence, also if damage caused makes it worse
Interesting.
What exactly was the problem with the pin?
My first thought too, you beat me to it. Sounds like a classic pin-over-5th wheel otherwise. But with an added complication being the same trailer.
I had a trailer with a very loose pin once. It did bang about noticeably and you could wobble the pin by hand!
But it didn’t fall off the 5th wheel.
I did a trailer swop half way up France. Gave another driver my loaded one and took this empty for loading in Spain.
The bill for repair was high, but no way was I going to load it and drag it that far when heavy. It was a bit naughty taking it empty to a workshop but, since it got that far…? Judgment call…
did you realise there was something wrong with the pin before you picked the trailer up
Picking it up was when the issue became apparent. Very difficult. The other driver who was dropping it said he had needed two or three goes at it.
If it was in a depot I wouldn’t have left the depot.
Half way up France in a Restaurant car park?
I took the fingers crossed and get it to a workshop option.
I don’t recommend that as the best choice, but it was the way I saw it then.
reason i asked was i had been on class 1 a few weeks drove up to the swap point all fine. when i picked up the pin on the other trailer i only heard 1 clunk got out and could see the bar across the pin did 2 tugs seemed ok thought sod it ill do an extra good one loud bang and the unit shot fwd. just managed to stop in time. Looked under the trailer at the pin and couldn’t see any damage or signs of distress around the base of the pin. Second time round same thing but this time it didn’t detach. Got a driver i was friendly with to come and check for me all seemed ok. However for saftys sake i did it a third time and got 2 clunks this time.
all ok down the motorway when i got near the drop on the way back and started going though town every time i stopped or started back up thee was a thump. when i got to my drop i explained what was going in to the goods in and asked if they minded if i dropped the trailer and picked it back up as i wasn’t happy. Again i got two clunks tug test all good etc. did the drop and set off back with the empty trailer. However this time slightest braking or acceleration produced a thump. dropped trailor at the clients then went back to yard and reported the noise and what had happened.
I got a phone call that afternoon saying everything was fine it must of been the trailer. This night however i was job sharing with the guy i shadowed to get a little more experience and some money. he picked up the trailer same thing happened to him with the same thumps every time he braked or accelerated. This time they decided that the 5th wheel was worn
This looks pretty good to me.
But NB it is for the USA market, so no mention of air suspension etc. And the casting for the dog clip is shown, but isn’t used.
What can happen is that the Locking mechanism rotates, so blocking off the view of the pin, * but* the lock bar (previously I called this the knife, I won’t anymore) doesn’t spring all the way across as it should.
That is when you have one click not two.
At this point
Because the lock bar isn’t fully across the dog clip can’ t be put in.
A tug test (a good firm one) will separate the truck from the trailer.
Or tug, reverse (second click) and tug again. Should sort it.
You might now see that with a trailer/unit at the wrong height the bottom of the pin strikes the top of the locking mechanism and the dog clip can be put in although the pin is not secure. That is why a good tug test is needed.
This video is about adjustment. It should never be necessary for a driver to adjust a 5th wheel but this does show the mechanism itself more clearly. In life however if will be under a trailer rubbing plate, covered in grease, but won’t be colour coded.
What I meant was trailer too high/5th wheel too low, enough to allow the pin to override the hole in the middle but touch, for the first time, on the plate beyond it. The pin then rides up the plate and drops over the front. Thus it is hooked and the trailer can be pulled away, however, when a sufficient turn is made, the pin travels towards the corner of the 5th wheel and becomes detached from it. I am not sure from memory if the bar can be closed enough to allow the clip to be attached.
The above has never happened to me, but I always recognised that it could, which is why I said above I always made the trailer too low so the the striker plate only just made it on to the rear of the 5th wheel. The pin is then forced into the V and could go nowhere but engage and click the bar.
interesting video. in my case it turned out that the lock jaw that rotates was worn allowing slop i guess
What I think happens is that the base of the pin slides inside the “V” of the 5th wheel grazes the top of the mechanism and the lock bar goes fully across allowing the dog clip to be inserted.
The base if the pin is inside the center of the 5th wheel. So the trailer is the correct distance from the back of the cab.
I think that the pin pushing down on the locking mechanism will push that slightly below the locking bar, so a gentle tug will not pull the pin over the bar.
I can’t prove the above. I see it as a possible explanation of what might happen.
I do accept that if drivers go under:
At the correct height.
Make sure the trailer plate is fully touching the 5th wheel (raising air suspension) to take the legs up, then,
Make a strong backwards push
Making a strong tug or two.
The above fault should not occur. It isn’t a mechanical fault. It is bad driver practise mostly related to wrong heights of truck/trailer.
It has happened to me. It was a cold and wet night, we had no air suspension then and… I blame no one but me.
The trailer slid off the 5th wheel and rested on the rear plastic mudguards.
It was hard work winding up a part loaded trailer in low range. No one hurt and no real damage.
I can see a way to overcome the issue though If the part of the pin below the groove was a larger diameter that the part above the groove then it could not sit inside the “V” if coupling at the wrong height was attempted.
Since it is rarely that Numpties (yes) attempt this, and it should be even rarer now we have air suspension I doubt a new standard pin and 5th wheel will happen.
My knowledge of air suspension is limited to the drawbar wag and drags we used at Toray to mount and demount swap bodies. I have never had an artic where the suspension could be altered and I wonder if for whatever reason some drivers go under with it too low. Dropping a trailer and picking it up again was not a problem because it was very difficult to wind a trailer too high because it was too much hard work.
Did you get to see how the pin was connected to the larger plate? If I was guessing I could imagine its a big rivet head perhaps.
I don’t think I have imagined it could go loose, just deformed from heavy abuse.
The trailer I cocked up was on Cherbourg docks at 22hrs on a winter Sunday night.
It would have been dropped by a tuggy.
Doubtless, I was looking enthusiastically forward to doing a half shift down the road…
By the time it was resting on the rear wheels I couldn’t rewind the clock to see what I had done wrong, but I have reflected on what it might have been.