we have A 2016 F250 with a steering problem. while driving down the road the steering wheel will pull hard to the left or right then switch with out warning, it will also do it if I make a hard turn like its stuck and you have to fight to keep the wheel straight
I have replaced the drag link, track bar ball joint, upgraded the steering dampener, had the front end alignment check (was perfect). and I'm still having the issue

 

Welcome to the site.. Sounds like a spooling valve issue in the steering gear (?)

 

ill look in to that i have taken it in to two places they just tell me its because i have bigger tires on the truck and the truck thinks its making a complete turn but is not if the tires rub do you think this could be true.

 

It doesn’t seem like your explanation is a ‘wondering’ front end (?) The concern that it dives to either side without input would be suspect. Is that correct? And that it hangs or binds deep in to turn radius wouldn’t seem tire size related. What over size are you running? Any way you can try a set of OE tires and see how it responds? Spindle ball joint? Sometimes on spindle joints if installed too tight, it will cause a bind, causing the front end to ‘dive’ on minor steering correction inputs. Being you seem to have made the parts changes as a correction, may not be a fault, but something I’d make sure is off the table.
Ive corrected quite a few ball joint repairs where the joints were way too tight, causing an issue with keeping the truck in a straight line mostly noticed at speed..

 

yes the sudden dive side to side is the concern, but when it does it you have to fight the steering wheel to keep it straight, this is the same when you make a turn and it also happens while your just driving down the road then it just stops, also it doesn't happen all the time, were running 37inch tires. before we had 35's
we are going to run stock tires this weekend we have been told to try that.