Fontaine 5th Wheel

You’ll feel much better with a new fifth wheel instead of trying to fix or rebuild a problem unit or a major problem if something happens.

 

I would think that it's a loose bolt, worn bushing, or hole being wallowed out along the operating handle. There are several connection points along that arm where it connects from the pull handle to the pivot point. If any of them has some play, it would allow the handle to move back slightly after locking.

KIT-OPR-6000 by FONTAINE - OPERATING HANDLE KIT

This is just a guess. If you can't get under the fifth wheel and look while someone pulls and releases where it has play, then you'll have to remove the plate and flip it upside down. You're probably going to need to take it off to replace whatever parts need it anyway. The only part I've been able to replace while still attached was the stop rod, and it was pretty tough trying to get the cotter pin in while holding back the spring as well as extremely greasy and dirty.

Here's a link to parts diagrams. It probably is a safer bet and easier to just slap a new one on and have peace of mind for the next however many years.
https://www.fifthwheel.com/pdfs/literature/LT-135_PartsCatalog.pdf

Oh, and if you do decide to try a rebuild, make sure you verify your fifth wheel model and get the correct parts. The link I gave to the part is just to give you an idea of what I was talking about, and may not be for your model.

 

Fleets that have a lot of the same trucks will re-buld them. Almost everyone else gets a new one, cheaper and safer.

 

Good choice. Let’s go Brandon!