Originally Posted by Jettech

What a mess. I have a 08 F250 super duty diesel and started noticing similar issue. With mine normal steering is good. Started noticing it's a little sluggish to return to center after a turn. Then one day after making a left turn, I gave it a bit more throttle than normal and after the turn the wheel wanted to stay left. I corrected drove a bit then got an uncommanded left input. Straightend, then got uncommanded right. this repeated for maybe a minute or 2. Then it was ok. Since then I have noticed that I can duplicate it by adding a bit more throttle during a turn. Otherwise I don't have the issue. Any chance it could be a bad belt on the pump? I don't have any abnormal noises, pulling, grinding. It is a bit freaky when it happens.

Originally Posted by IronDioPriest

Front U-Joints. Trust me.

Originally Posted by jayjjcc

Check your PS fluid. Mine smelled like burnt shhhhhh it and it looked like mud. I changed the pump but I swear the fluid change is what corrected my problem.

Originally Posted by IronDioPriest

I encourage everyone who has experienced the problem SPECIFICALLY outlined at the outset of this thread to heed the advice of those suggesting the front-end U-joints at the culprit.

The U-joints LOOKED fine, so they were initially OVERLOOKED by the mechanic as a cause of the steering malfunction. But based on the advice found in this thread, I asked him to take another look. He locked the hubs and watched the U-joints as he turned the tire. Sure as heck, they reached a point in the rotation where they bound up. It SHOULDN'T happen, but it does, and that is why this answer is non-intuitive.

If you come out of a turn, and suddenly your steering jerks in the direction of your turn, and trying to correct it takes the wheel past center, jerking it the other direction, and you wind up not being able to steer straight, turning the wheel from left-to-right, never being able to center it - if stopping and turning the wheel from lock-to-lock temporarily solves the problem - the very first thing you should look to is your front-end U-joints.

After a few very frustrating weeks of misdiagnoses and un-needed repair on worn-but-still-functioning steering components, and still having this intermittent problem resurface, I had the U-joints replaced. I drove the Excursion with 19.5' fiberglass boat in tow 500 miles to Lac Seul over some rough terrain, and my problem is GONE.

Thanks to those on this thread who crowdsourced the solution to my problem.

Originally Posted by Carrie Lee

Thanks for all the info EXv10. I have an 05 Excursion Limited with the 6.0 and mine just started this jerking wheel back and fourth. We replaced the steering box but still didn't fix it. I guess now I will replace the pump.

Originally Posted by IronDioPriest

...or the front end U-joints....