Funky/Odd Power Steering issue

[SLC97SR5]

Returning home from a 1,000 mile trip with the family the Ford's steering wheel jerked to one side and as soon as I corrected, the steering felt overly sensitive for a moment, then returned to center.

It freaked me out as I thought I had a rod-end or ball joint letting loose. I got off the highway and thoroughly checked the front and rear end over.

Things checked:

PS fluid level
Belt tension
F&R U bolts
F&R lug nuts
Trackbar
Rod-ends
Ball-joints
Pitman arm
Shackles are tight
T-case in 2WD
Hubs unlocked
Tie-rod and drag link rotate fore and aft when the steering wheel is turned.
All greaseable fittings are well lubed.

Everything appears normal, no slop, no leaks, no noise, nothing odd except for when travelling straight for several miles at a constant speed the steering wheel will abrubtly fall off center and remain cocked until I give adverse input.

It did it today coming home from work.

I have an idea but I don't want to contaminate anyones opinion.

Any thoughts?

The Truck is below:

1994 Factory Turbo, CC, LB, 4X4, BTS E40D, Moose Pump, matched BB's, ATS exhaust housing, 3" DP & straight piped, 4.10's and 265's, 88gal aux tank.

 

[bryson]

Had a coworker that had a similar issue on a Super Duty and I believe it ended up being a missing tooth on the sector gear in the steering box...

Scary stuff!

 

[I Lean]

Yeah, I'd guess you're going to replace your steering box.

 

[SLC97SR5]

^^ I had thought about that, I was also considering the pump itself.

Possibly a bypass/proportioning valve sticking?

 

[Rot Box]

Look out for is seized up front axle shaft U-joints... They can lead to really weird issues like that. I experienced similar symptoms when mine started to freeze up on my last Cummins. They would bind up randomly then throw the steering wheel one way or the other. Scary as hell

 

[cowmilker]

Is this happening when you are just driving straight down the road (you said you were on the highway) or as you are turning at lower speeds? My truck (92 f350 CC 4x4) did something similar when the top bearing in the steering column went out, it would get stiff, then break free (only at lower speeds turning 90 degrees, like when coming away from a 4 way stop). Replaced the whole column, problem went away (took me some time to find a good column, every junkyard truck had a missing or torn apart colomn).

 

[cowmilker]

another thing I have heard is that if your fluid is foaming up it will cause some surging within the system.

 

[4Chin]

Im thinking gearbox too. Perhaps a missing tooth is floating around the box, and intermitantly catching on something else, binding the whole operation. I think NAPA sells a gearbox for around $250. PN: NSP 88278067. Good luck with the pitman arm.

 

[SLC97SR5]

It's funny you bumped this, I just got finished replacing the PS gear box. It locked up momentarily on the freeway friday night.

I will be tearing the old box down to determine the failure.

That pitman arm was a bad mofo.