Hi all
Following on from my previous post on coupling, I just wondered, when coupled to a trailer can the kingpin/fifth wheel become damaged by going over potholes, speed bumps etc. too quickly?
It’s just on my run today I failed to notice a raised manhole cover until it was too late and went over at quite a speed and I’m a bit worried now I could have damaged something!!
Thanks 
I work on trucks all the time and you have to hit something pretty hard to damage the fifth wheel like that. I’ve seen the pin torn out of the trailer before the fifth wheel gets buggered. Remeber things like suspension take a lot of the force out of the road as well.
Arborist:
I work on trucks all the time and you have to hit something pretty hard to damage the fifth wheel like that. I’ve seen the pin torn out of the trailer before the fifth wheel gets buggered. Remeber things like suspension take a lot of the force out of the road as well.
Not really on topic but I’ve always wondered wether there has been any instances of pulling the pin off a trailer. Many experienced guys I have asked have said they haven’t heard of it so guessing it’s pretty rare?? Be interested to know 
UselessForce:
Arborist:
I work on trucks all the time and you have to hit something pretty hard to damage the fifth wheel like that. I’ve seen the pin torn out of the trailer before the fifth wheel gets buggered. Remeber things like suspension take a lot of the force out of the road as well.Not really on topic but I’ve always wondered wether there has been any instances of pulling the pin off a trailer. Many experienced guys I have asked have said they haven’t heard of it so guessing it’s pretty rare?? Be interested to know
There have been a couple of examples on this forum of pins failing, but I suspect it’s very vary rare.
And I’d have thought it’s probably very old trailers where fatigue comes into play.
But overall you’ll be surprised how strong the kingpin is! 
I’ve seen a better one, but can’t seem to locate it. 
Best way to test the kingpin and fifth wheel is to go down the A68 near colt crag reservoir, loaded and on the limiter. I don’t think any other road would put as much strain on the pin.
(Obviously I Wouldn’t do this in case the do goody brigade are out)
Evil8Beezle:
UselessForce:
Arborist:
I work on trucks all the time and you have to hit something pretty hard to damage the fifth wheel like that. I’ve seen the pin torn out of the trailer before the fifth wheel gets buggered. Remeber things like suspension take a lot of the force out of the road as well.Not really on topic but I’ve always wondered wether there has been any instances of pulling the pin off a trailer. Many experienced guys I have asked have said they haven’t heard of it so guessing it’s pretty rare?? Be interested to know
There have been a couple of examples on this forum of pins failing, but I suspect it’s very vary rare.
And I’d have thought it’s probably very old trailers where fatigue comes into play.
But overall you’ll be surprised how strong the kingpin is!I’ve seen a better one, but can’t seem to locate it.
i’m one who previously posted as having a king pin fail 
but never had any fifth wheel problems so far.
youtube.com/watch?v=VEVzITsnVIw
Link shows twin drive unit suspended from its 5th wheel/trailer pin. Strong enough for you not to worry about normal usage I`d say.
The only time we have had them tear out is when we go out to pretty serious RTC’s usually involving rolling the truck above 50 while fully loaded. But it’s so rare it’s unreal and like I say you are more then likely to rip the front of the trailer off then break the 5th wheel coupling.
Arborist:
The only time we have had them tear out is when we go out to pretty serious RTC’s usually involving rolling the truck above 50 while fully loaded. But it’s so rare it’s unreal and like I say you are more then likely to ripe the front of the trailer off then break the 5th wheel coupling.
I say you’re more likely to foobar the chassis long before you’ll rip a turntable off.
Some interesting stories and videos, my dad has been involved in the transport industry for around 54yrs and he’s never heard of it, this is going to sound stupid but you obviously expect it all to be strong due to the nature of its role but I’d never realised just how strong it all really is!