king pins

A company I worked for years ago had it on their PM sheet 1/4" max. That was movement measured from the tread grove on top of the tire. Tire jacked up off the ground with a bar through the wheel whole at the bottom. The tape measure ran to the frame, engine or something and move the tire with the bar.
I feel the 1/4" is a bit excessive but when your tires wear funky with 1/16 play I thank blaming it on the king pin is B/S.

 

That's one nice thing about my Mack...tapered kingpins. Got a little slop? No problem...just tighten them up a bit.

1/4" does seem a bit excessive...shortens tire life and beats the heck out of tie rod ends when that kingpin lets the wheel flop around at speed.

 

Tanker pins have to be inspected evey5 years. My carrier just changed the plate as a matter of SOP.

The pin is very resilient, any slop is likely the 5th wheel jaws or plate.

I bought ( LP ) a truck that was 10 years old, had some slop in the 5th wheel. tried a "per procedure " adjustment and wasn't satisfied so I replaced it with new. Too risky imo to try and save money in this area.

JMO

 

OP is talking about the king pins on steer axle of truck, not the king pin on a trailer, hence the reason in his question that he specifically says truck king pins.

 

Tapered kingpin?Are you talking about the tapered lock pin on the axle eye?

I am getting old,just looked it up.Never saw a tapered kingpin before.Looks like a good idea.

 

If you decide you need to replace them, and you own the truck, may I suggest staying away from the Kaiser no reams. On my truck and several others that I know about, they for some reason chew into the spindle. Stay with the traditional brass bushing press in's. By the time you buy a spindle $1200+. I put a brand new complete drum to drum axle in cheaper than 2 spindles. Just food for thought.