Steering Sticks

The basic description that I have been giving people is that the steering will "stick" or "lock up" to the point that I have to use some force to get the steering wheel past the stuck point, when it releases, it's a "jerk, " THEN it sticks the other direction and I have to force the steering wheel back the other way again. So, in other words, when the truck decides to do this, in order to drive a straight line I am literally turning the wheel back and forth, probably only an eighth of a turn each way, but back and forth. If it's bad enough, I have to pull the truck over. If I pull over, sit and turn the wheel back and forth a few times, loosening it up (when I'm stopped, I can't say that I really feel it stick at all), I can pull back on the road and be fine. A lot of the time, it happens right after I've turned a wide corner (not specifically right or left. It does it both ways), say taking a corner at an intersection as a yield or turning through a wide intersection onto say, an entrance ramp to the highway. I've had it happen on Main Street in O'Fallon where the speed limit is 35, and on an entrance ramp to the highway. I've noticed it a little milder when I'm doing 60-70mph down the highway, it just doesn't "jerk" quite as violently at those speeds. I would say in a lot of cases, even when the truck doesn't have "an episode, " I can still feel a stiff spot when I'm driving down the road/highway. This is not a vibration-type problem.

The garage/mechanic never could seem to get the truck to act up but felt like it was the steering box. Since I was kind of stuck, not knowing and not being able to drive it, I finally told them to just do the steering box after they had the truck for around 3 weeks. Didn't work. I drove the truck to work3 times before I finally got it to act up coming home again. I kept thinking I felt it slightly, but wasn't positive until it had an episode getting on the highway coming home.

This all started this spring. It didn't start out being the "violent sticking" back and forth, but just felt like tight spots. I immediately thought of power steering fluid because I had seen a puddle on my garage floor a month or so prior but hadn't been able to determine where it had come from. The puddle never returned and I honestly can't say for sure if I specifically checked the power steering fluid or not. Anyhow, when I checked the fluid after the truck started acting up, it was very low in the reservoir. I re-filled. The problem did not improve. I tried drawing a lot of the fluid out and re-filling with some Lucas Oil power steering additive. Still did not improve. By this point, I think it was locking up from side to side like above.

Everyone's first thought seemed to be the power steering pump but I think that was just because of the fluid issue. I talked myself out of this and the mechanic kind of confirmed because if the power steering was bad, it would be binding up when I'm stopped or moving very slow and turning the wheels, not at the faster speeds. I don't notice it doing this. It's been difficult to diagnose since it can go a hundred miles or so between episodes. Some are leaning back to the power steering pump and indicating that the hydraulics could be slipping and allowing the fluid pressure to drop, leaving me with more "manual steering" for a moment before kicking back into automatic, thus causing the overcorrection and need to turn back the other way. Which of course is a never-ending circle of events.

Please, I'm looking for any suggestions here as I'm worried about driving the truck as-is. Steering is not something you want to have a problem with at 60 mph.

Thank you!