5th Wheel issue

Sounds like you need a rebuild. The jaws are a little worn down. Unless you have a floating 5th wheel then it might need to be shimmed

 

Toss that 5th wheel.

Slap a new on there. Or change tractors. It is one of my buttons that if I have to drive through a small town with nothing but red lights being bumped in my tail bone, I am going to be pretty enraged by the time we get clear of that crap.

 

I concur.

 

I visually check the clamp is full around the king pin. EVERY SINGLE TIME. I don't care if I'm going across a parking lot. Things go bad when trailers come loose, even at low speeds. You're definitely going to get a serious workout cranking it back up, if you can. At high speeds, it's a monstrous catastrophe. A 30 ton battering ram. People get dead sometimes. I've watched trailers tip over a couple times because they broke loose in a parking lot. Very expensive all the way around.

Check it every single time with your eyes.

A bad fifth wheel ? Refuse to drive it

 

I agree. 5th wheel needs cleaned, rebuilt, and properly adjusted. Get that truck in the shop

 

As some have said, listen for the jaws to snap closed, always give a tug while the landing gear is down and always look at the release to make sure it's all the way in and make sure the jaws are closed as well before you crank up the dollies.
I would add that after the tug you reverse as well just in case the jaws are only partially closed, gives a second chance for the jaws to close completely if they happen to be slow from excess grease or rust, and this way it's easier to pull the pin if you have to re hook, takes the pressure off the jaws.
Life has taught me that it's not always the 5th wheel's fault or the driver's fault if a trailer get's dropped, but some clown who thinks it's funny when a driver looses their trailer, which is why I made a habit of checking my 5th wheel before I left a truck stop or anywhere else where there were people and the truck was out of my sight for any length of time, it only takes a couple seconds for some clown to pull the pin.
As for cleaning, a small putty knife or scraper, and diesel fuel if needed, is ideal for removing hardened and excess grease.
I used to wash the 5th wheel every time I washed the truck, but I would do my degreasing before I went there, just because I respect the owners and other truckers.
I don't like stepping in grease and other truckers crap and I don't suppose they do either, well......., most of them, I hope.
I learned a trick about greasing a fifth wheel, you don't grease the entire plate, just the back half, because the first trailer you hook to is going to smear the rest of the plate with grease and it won't squish out and onto the sides or over the front of the 5th wheel.
Sometimes it's not the fifth wheel causing the hammering when breaking.
I pulled a lot of trailers where the kingpin was worn and they did the same thing.
It was random, I might pull 10 to 20 different trailers a month and every once in awhile I would get one that hammered the fifth wheel under hard braking.
Solution, pull the trailer spike before you hit the foot brake.