Play in trailer kingpin, how much is OK?

I use two or three of the prefilled packets of grease. Slap one ahead of the angle plates on the back of the 5th wheel and one just at or above the front of the hole. Connect in such a way to make your 5th wheel flop over flat under the trailer so it will smooth that all over your 5th wheel.

Lithium grease if I remember right did very well in wet situations.

 

I'm going on 2 1/2 years same truck and trailer without any issues.

Keep the 5th wheel greased and you won't be thumping so much. Mine goes away as long as it stays greased up.

 

All good advice. Someone did mention or ask if you drop & hook to different trailers. Could be worn out kingpin. One other thing I have seen is. When unhooked look up under at where kingpin is welded to the trailer 5th wheel plate. Never saw the weld broke, but have seen the 5th wheel plate cracked around where the iron finally got stressed. I know grease kinda covers up cracks so use an old glove or piece of wood and create a view around it. Probably not the problem..but could be. On aluminum framed trailers that plate is bolted on. The plate where the kingpin is connected. After a few years that whole plate could be getting loose. Aluminum and steel don't get along together. This takes time to happen. I got to say that mechanic should've walked out and watched it while you move back and forth to see whats going on. Or someone wiser than him to watch. Fifth wheel issues not something to take lightly.

 

Some fifth wheels are prolapsed or collapsed, not flat. You can tell that by grinding sounds during turns. We had to cut out and reweld a plate around the kingpin on one flatbed.

 

yes, that would be me saying that i get what hes saying. but at the end of the day, what @baha said only makes sense to drivers that know what hes saying.

 

fixed your post. your welcome. don't worry about the ignore, i consider it a vacation

 

Free play in a 5th wheel should only be .040 to .080 inches... Here is a video that shows a special tool for checking 5th wheel adjustment and 5th wheel locks. There are many types of 5th wheels and each has a different type of adjustment method but the principals shown in this video still apply.