Hello Ford Truck Enthusiasts, nut Jobs and all decent people.
I have a problem which is probably better described as the biggest headache in my life.
I drive a clean bodied 1999 F250 SD with the 7.3 and 4x4 (Production Date 09/98), roughly a year ago I hit a wall on the highway causing my wheel bearing, axle shaft and wheel to all be destroyed. This was all replaced to no issue. Well... Roughly 45 days ago my truck started to randomly and violently pull to the left while driving, this happens on level smooth road, and unlevel bumpy roads. It does not care, it is dangerous. Sometimes it feels as though the entire front end itself is shaking as though the tire(s) are loose.
Thus far I have replaced; Wheel, Warn Hub, Axle Shaft, Track Bar, Pads, Rotors, Caliper, Brake Hose, Sway Bar Links, Wheel Bearing and ball joints to no avail. I am not one to throw parts at a problem and at each point had thought I had figured something out. I am kind of at my wits end here. I try not to drive it but to attempt to fix it, and often you'll be counteracting the hard left pull and it will suddenly free itself and drive straight as an arrow. I've taken it to two shops, who I must say don't specialize in anything like this but have replaced components to no success, what is funny is the trackbar was wasted. Another thing I feel I should note is that this behavior started while I still had the axle shaft removed.
That is all for now if I do not get dragged off to the looney bin.

 

Did you have both axle shafts removed? It could be a seized axle shaft u-joint in the other side. With the hubs unlocked and the transfer case in 2wd, turn the wheels 10 degrees or so to one side or the other. Using a small pry bar, see if you can turn the axle shaft a full turn with little to no binding.

 

I did not remove both shafts when I replaced the driver side. But I did what you recommended and both axle shafts are spinning freely. So I don’t think the problem stems from that. Thank you anyways.

 

Ok. That's the first place to check when there's any front end binding. It's very commonly misdiagnosed, but it sounds like your problem is elsewhere. It looks like you've replaced pretty much everything but the steering gear. Have you tried to get it to replicate the problem with the front wheels off the ground, or even just sitting still?

 

The gearbox is my next step, it’s expensive but. Outside of an axle I don’t know what else I can directly do.
I have attempted to replicate it to very little success standing still. That’s how I found the trackbar bushing was bad which I very honestly thought would be the issue. I haven’t had the opportunity to try to do it with the front end suspended but that’s on my list for tomorrow, I purchased some jack stands. When standing still there is play in the wheel and clunking with the pitman arm before the wheels actually turn I have noticed.

 

Im no expert on this and don't know if these are incorporated into these trucks, but in the steering box Im told is a "centering valve" function. The following is the AI version of one failing. A failing or stuck power steering centering valve (often called a spool or control valve) causes unpredictable, stiff, or delayed steering. The valve fails to balance hydraulic fluid correctly, resulting in uneven turning resistance, the steering pulling heavily to one side, or the vehicle wandering on straight roads

 

Yeah I'd certainly consider the steering box.

I saw the shuttle valve fail on a 3rd Gen Ram 4x4 and he had no assist to the left. It didn't pull, but was very difficult to turn left.

Unfortunately all the parts store boxes are junk. I'd get a Blue Top but they're expensive

 

I'm assuming your accident was on the driver's side?

One thing that crossed my mind is the left caliper seizing due to a pinched brake line or debris in the line. A cheap IR thermometer can be useful for checking that it's not friction / drag induced by measuring the temperature difference between brake / hub components across drivers and passengers side.

 

He did say:
"Thus far I have replaced; Wheel, Warn Hub, Axle Shaft, Track Bar, Pads, Rotors, Caliper, Brake Hose, Sway Bar Links, Wheel Bearing and ball joints to no avail"

 

Steering box is original, it had massive slop regardless. I’ll probably order a red head one anywho. Seems like my best course. It seems like a geometry or steering thing more then brakes as I haven’t noticed a temperature difference with my IR laser gun thing.

 

Blue Top > Redhead but whatever

 

why do you say this?
I only know the guy that owns/ runs blue top used to work at redhead. I've heard quality went down or is hit/ miss with redhead but not sure if that's gotten any better.

Are there any other solutions you would go with? I may eventually be doing something for my project truck. I run a redhead on my sig truck...pre blue top existence...but i've seen stuff from PSC, Lee's, saginaw pump swaps, etc.