Super Duty Steering Wander
Q I have a 2000 Ford F-250 Super-Duty 4x4 with the V-10 and automatic trans. I purchased the truck new, and it is used as a farm truck. It has regular maintenance performed on it. The truck has 100,000 miles on it. Lately, as I drive down the road, it tends to wander from one side to the other. I had the local Ford dealer put in new ball joints and align the frontend. I have also tried two new sets of tires, and the pickup still wanders. Is there a bad seal, or something in my power steering or steering sector that could cause this?
Dennis from Iowa
Via the Internet
A I get a lot of questions very similar to yours. Okay, it's a farm truck. I grew up farming, so I know just how much hard use the truck is getting. Most likely, one or more of the steering components is worn. You were right in replacing the ball joints, as there is a factory Tech Service Bulletin out on that subject. Hopefully the mechanic replaced the lower ball joint with the greaseable lower ball joint (p/n 1C3Z-3050-AB) and replaced the upper joint with the current replacement part (p/n F6TZ-3049-AA). I would think that the dealership that put in the ball joints and did the alignment would have noticed if there was any wear in the other components. But then again, if his work order just said, "Do an alignment" that's all he is going to do.
Let's start at the outer ends. The uni-bearings your truck uses may be at the end of their useful life. Jack up one front wheel at a time off the ground, naturally with the truck secured from moving. Sit down and grab the top of the tire and give it a good hard shake, in and out. You should get no to (maybe if you shake hard enough) a slight, but very slight, movement of the wheel/tire. Any movement means it's time to replace that uni-bearing.
The next step is to crawl under the front of the truck and have someone turn the steering wheel back and forth, with the engine off, just enough to take the slack out of the steering but not enough to move the tires. Watch for movement in the tie-rod end and in the sector shaft of the steering box. Where there is excessive movement, you have found the problem.
The problem could also be caused by sagging of the front springs, which would change the caster angle. Not enough front-axle caster could very easily cause a wandering problem, but then again, if the tech did an alignment he would have caught that as well as the loose bearings. How about the condition of the spring eye bushings? Watch for spring movement when the steering wheel is moved back and forth. Check to see if the U-bolts that hold the axle to the spring are tight.
And one last thing: go to the rear axle-yes, the rear axle. If it is moving around from a worn spring eye bushing or loose U-bolts, it could be causing the wandering problem.