Power Steering Problem?

[iamjose]

I'm not really sure how to explain this but the other day I made a couple of turns, nothing out of the ordinary, a left at a stop light and one of those half circle freeway on ramps (two different days, not consecutive) and I noticed it was a struggle to turn the freakin wheel. I haven't noticed it before or since. I thought I might have been low on power steering fluid but it was right up on the fill line. Anyone have any ideas what might cause this? 2002 Ford Explorer XLS 4WD with about 145k and I just recently bought this truck in may...

 

[iamjose]

just a bump to see if anyone has any suggestions...

 

[IZwack]

Lets do an experiment - but like all experiments, we need a "control". So find a turn where the symptoms arise every single time - like a parking lot with tight turns. Once you can recreate the symptoms, its time to execute the experiment. Hypothesis - 4wd is engaging (due to some reason). We dont need to know the reason now why 4wd is engaging, we just want to know if 4wd is indeed engaging. So, one way we can can figure out if 4wd is engaging is by removing the front driveshaft and then going back to our control environment to see if the difficult in steering still exists. If the steering feels normal, then 4wd is engaging. If the steering is still difficult, then the issue is not related to 4wd. If the steering feels fine, there then are a few reasons that can cause premature 4wd engagement - such as low tire pressure, uneven tire wear, sensor issues, etc..