fifth wheel slack

[cowdoc]

OK I'm a relative newbie so please be gentle. 1998 43ft Timpte hopper is the trailer. We've pulled it with 3 different trucks lately and there is slack in the fifth wheel/kingpin on all of them. You can feel it when you take off and sometimes when you change gears. This trailer has 90 inch sides and we load it pretty good. 100K gross and 25-26K tare depending on fuel status. Can the kingpin be built up around the base or what can be done I guess I'm asking. Thanks.

[pdm]

Most truck/trailer shops will have a king pin guage to check the wear on the pin, & can also check the 5th wheel. You can also leave the trailer brakes on & gently tug against the trailer while watching where its moving.

[PhuzzyGnu]

On my Holland fifth wheel you just turn the bolt on the starboard side and it tightens right up. A little turn goes a long way . . .

I'm not sure why your mechanic couldn't tighten up the fifth wheels a little.

-p.

[Maniac]

Can the kingpin be built up around the base or what can be done

No it can't, but it can be replaced though, a lot of welding though, and should definitly be done by a pro welder.

Kingpins usually don't wear out though, I'd say its the 5th wheel

[cowdoc]

There is no wedgebolt on this fifth wheel. I'm thinkin 5th wheel needs rebuilding. Kingpin probably worn too. I appreciate the help.

[bob h]

OK I'm a relative newbie so please be gentle. 1998 43ft Timpte hopper is the trailer. We've pulled it with 3 different trucks lately and there is slack in the fifth wheel/kingpin on all of them. You can feel it when you take off and sometimes when you change gears. This trailer has 90 inch sides and we load it pretty good. 100K gross and 25-26K tare depending on fuel status. Can the kingpin be built up around the base or what can be done I guess I'm asking. Thanks.

The obvious is checking the 5th wheel adjust on each unit, and then check kingpin wear with a proper gauge.

Yes, kingpins can be rebuilt; the pin is built up with weld, and then machined back down to the proper size.