Wheel Nut:
Although the dog clip is fitted, it only locks the release handle, it has absolutely nothing to do with the jaws locking around the kingpin.
Worn Jaws can cause trailers to become detached.
These are the bits that wear out! A broken or worn spring is enough to release a trailer.
Another important part of modern fifth wheels is a polymer wearing ring that fits into the cast bed. To replace them is simple, 3 set screws and remove the white horseshoe, clean it up and fit a new one. There were several failures on the MAN units that Transalliance ran, and it became second nature to check & change them on routine service. A five minute task.
Have you ever heard the term ‘‘trailer slapping’’ ? Its when your pin moves in the jaws only small movements usually when breaking or at junctions - but its enough to make loud slapping noises. If there is movement in the jaws could this be worn parts?
Wheel Nut:
Although the dog clip is fitted, it only locks the release handle, it has absolutely nothing to do with the jaws locking around the kingpin.
Worn Jaws can cause trailers to become detached.
These are the bits that wear out! A broken or worn spring is enough to release a trailer.
Another important part of modern fifth wheels is a polymer wearing ring that fits into the cast bed. To replace them is simple, 3 set screws and remove the white horseshoe, clean it up and fit a new one. There were several failures on the MAN units that Transalliance ran, and it became second nature to check & change them on routine service. A five minute task.
Have you ever heard the term ‘‘trailer slapping’’ ? Its when your pin moves in the jaws only small movements usually when breaking or at junctions - but its enough to make loud slapping noises. If there is movement in the jaws could this be worn parts?
Yes, or simply out of adjustment, defect it, or have a look at that wearing ring I mentioned somewhere.
Beat me to it, Norbert Dentressangle’s Renault Premiums dont have a dog clip fitted…
But you can always buy one from a hardware store for less than a £1 and keep it in your lucky bag with the bulldog clip for the rear no plate!
They don’t have one because they don’t need one, not because it’s missing.
But if there is hole for a clip, why not fit your own clip? Less than a quid and a bit of extra piece of mind?
The clip isn’t going to make a scrap of difference to the trailer staying on or not.
The trailer coming off is not something I worry about, I just make sure I couple properly and do the duck under with the torch thing so as I already have peace of mind the clip wouldn’t add to that.
this is whats caused with a faulty 5th wheel? yep it was me!!! and the dog clip was in, and the arm was out in the open positon afterwards as well, the arm had shot over the dog clip, lucky it was a sunday when this happend or someone may have been killed as the trl left the road and went like a speed boat thro a brick wall,down the car park and into the building ,
reason this been was the trl was in the closed position when it came off and the landing legs tuck"d up hitting the shut button!!! hence this is why the trl went so far by its self, as it had no brakes by that time
Darb:
I passed a trailer ( from a wagon n drag ) in lane1 on the M1 just after jct 30 a few nights ago, there was no sign of the wagon, there was just a car on the hard shoulder with its hazard lights on just a few yards before you got to it.
I couldnt understand where the wagon was if had dropped of wouldnt it have pulled out the suzies stopping the unit ■■
I saw that… amazing that the Magnet driver drop that drag in Lane1 on the uphill climb to J30…
I do wonder though how its done on the W+D as I never been trained on coupling on them? is it a bar that clamps down or something?
Anyhow… I am with Lucy on the torch front.
When going under, before locking in - raise unit to full height and slowly ram it in nicely, 2 tugs, dog clip in and quick flash of the torch to make sure the arm is fully across the pin and trailer is sitting nicely on the plate.
,
if had dropped of wouldnt it have pulled out the suzies stopping the unit ■■ 
