Fifth wheel play

Judging from those high quality pics,

I got nothin

 

Separate the tractor from the trailer. There should be pins/bushings in the circled area. Use a bar from the back or side to check for play.




If you don't see a problem there then check the suspension.

 

If you’re worried about it leaning, drop the landing gear, once the other side gets loaded, raise it back up.

 

Could be a worn out kingpin too.

 

The play in the 5th wheel jaws can be checked. See pic. There is also an adjustment to compensate for wear. There are also kingpin gauges. Unlikely though that either of these would be related to the gap you show in pic.

 

I've never seen a trailer sit perfectly flush and tight to the top the plate when being forced to one side or the other. I think this is normal. It is the side to side, front to back play that is important between the pin and plate and jaws, not up and down. You do need some up and down play to allow for give when going over uneven surfaces side to side. Sometimes when we do quick grease jobs, we lower the landing gear, then drop the air suspension on the truck. This always forms a small gap between the plate and trailer large enough to get a grease gun hose in there to grease the 5th wheel plate without disconnecting the trailer.