About two months ago my truck started to have a steering bind about every 180 degrees. Aka around center its fine, turn 90 deg either way, and it binds up, force it past, and then its free until another 180 deg. A shop thought it was the pump and replaced it, but no change.

From what I've learned from searching, it could either be air in the box, a binding steering column/balljoint, or a bad box.

Since this started without disassembling anything, and the fluid level was correct at the first incidence, I'm crossing that off. Binding steering column is possible, the lower bearing could be a whole lot better, but I did a test that makes me wonder:

I put the truck up on jackstands, and with the engine on it always happens in the same spot. When I stopped the engine and cranked the wheel, it was the same resistance from lock to lock. And so it seems like during the bind it acts like you have no hydraulic flow, and then it resumes as you go past. It seems to me that if it was a bind in a ball joint or steering column it would act the same with the engine off, right?

Could this be a piece of debris blocking a port internal to the box? I dont know enough about the design to know how it could act like this. If it is a blockage, is it possible to back flush the box to try to loosen something up? I would absolutely hate to blindly replace the box, because including faulty boxes that died within a week, a new box would be #6. If this box is bad, it only lasted two years Of course, I would only get an AGR box if it was necessary

Thanks for any advice

 

Binding that just starts for no reason is often the result of cab mounts rusting out and the cab sagging - causing the linkage to bind at some point. I'd check carefully for this.

Put it on jack stands again and have someone else turn the wheel while you check things out. It could be the pump but I'd look for mechanical binding first. Look at everything including king pins (you don't have ball joints do you?), tierod ends, pitman arm, etc.

 

Okay, an update. I removed the rag joint, and manually moved the u-joint at the base of the column. In one direction it freely flopped back and forth, in the other I had to really pull and push to get it to move. With someone in the cab moving the wheel towards the binding point, I had a really hard time keeping the shaft pointed in the right direction. And it just so happens that at the binding points the sticky side of the joint is at maximum deflection. So Eureka...hopefully

You are probably right on with cab sagging, the u-joint may have had to move just slightly more than before and showed its deterioration.

And yeah, no ball joints. I've gotten so used to independent front suspensions that I'm not always as careful as I should be with terms

 

So the follow up last update. After looking at all the options for replacement shafts, I went and bought the Borgeson 975 unit. Got it this morning, and after a whole bunch of careful measuring and cutting it to the right length, it works perfectly. Cant believe how much better the wheel turns compared to even before it "broke". I tried replacing the lower column bearing, even found the perfect replacement bearing at the local ford dealer speced for a 80 F150. But unfortunately the real problem is the shaft being worn in the column, and the bearing holder not being all that secure. So one of these days I'll have to pull the column and rebuild it on the bench.

Now to drive by the shop that replaced the pump and wanted to replace the box and teach them about this fix. Its a good thing I still like them.

 

Happy to hear you got it sorted out!