5th Wheel issue

What happened is you had a bad hook. It happens from time to time. It's why you tug as soon as you hook (before you raise the landing gear) and VISUALLY CHECK THE JAWS with a flashlight every time.

It looks like you have a little grease build up. Manually trip the 5th wheel, the pour some diesel over the jaws and the locking mechanism as you work the handle in and out. Do this once a month in the winter and a couple of times during the summer and you will rarely have bad hooks

 

It wasn't properly locked. If you looked with a flashlight you would have seen the jaws only 50-90% around. Most bad hooks will pass the intial tug test, but will disconect with any kibd of real motion, especially if you pull twoards the right at all.

When YOU (not the shop) trip your 5tg wheel manually, watch how fast it snaps around . Once you pour the diesel over whilr working the handle , trip it again and notice the speed difference.

 

Yes, the hard pull is indicative of grease build up.

Take a crow bar and push where rhe kingpin would hit. It will take some force, but it will trip the jaws and they will snap around and closed, but not that quickly. The problem is the grease build up delays or slows the jaws enough so they drag on the king pin and don't lock all the way. Most of the time it looks like your picture, but sometimes it gets almost all the way and you can see just a slight sliver of differnt shaded metal.

 

I'm wondering if you are driving a Volvo.

I dropped at trailer at low speed on a Love's parking lot in Kansas. This was after having pulled this trailer from California.

Ended up taking said Volvo to a dealership in KC. They fixed it and I picked up a load going back to California. My co-driver had problems hooking to another empty in California, so we bobtailed back to the yard.

The competent folks at 8 Point fixed it and all was well. It was a wonder that trailer didn't drop along the interstate.

The moral of the story is that the 5th wheel in question might be broken and in need of expert repair by a specialist.

 

If you greased a colt model semi automatic and left it be inside the fire control area where there is a lot of fine tolerance parts moving together, you will find that the grease (Oil, lube whatever it is) will harden and build up over time. If you fail to clean it regular, that build up will have the disconnector sear in the wrong position so when she shoots one round, the pin is not going where it's supposed to go and will fire the next round in full automatic. ZIP 10 rounds gone. Usually to the sky.

A fifth wheel may fail once in a while in this manner. Always without fail in this case tug your trailer after hook. Even if you had a nice CLANK! that reached into your soul. Always tug it. If you do not, she's going to sneak off there in say Dumfries VA during rush and YOU will be very famous for all sorts of bad reasons...

 

Does anyone else feel a slight bump from a take off from a stop light from the trailer sliding back?