3400 Ford Power Steering Question

Craig Kruse · Jan 11, 2013

I notice my power steering is harder than I think it should be and I found that my steering shaft goes up and down a little bit when I turn from left to right and vice versa. The question is - is the steering shaft supposed to go up and down slightly when turning. My manual says it travels axialy but I'm not sure what that means. Is axialy equivelent to verticle? Oops that's two questions.

Sean in PA · Jan 11, 2013

It should go up and down very very slightly. So slightly that it should almost be unnoticeable. The up and down movement is what actuates the control valve that directs the hydraulic fluid to the cylinders for the hydraulic assist, but if it is moving up and down to where it is noticeable to you, then the upper thrust bearing is likely worn to the point that the whole shaft is moving up and down, including the control valve housing, so the control valve is not working as it should.

Craig Kruse · Jan 11, 2013

(quoted from post at 15:34:42 01/11/13) It should go up and down very very slightly. So slightly that it should almost be unnoticeable. The up and down movement is what actuates the control valve that directs the hydraulic fluid to the cylinders for the hydraulic assist, but if it is moving up and down to where it is noticeable to you, then the upper thrust bearing is likely worn to the point that the whole shaft is moving up and down, including the control valve housing, so the control valve is not working as it should.

Well, Darn..... wish I had noticed this when I was fixing the leaky shaft seal. I have about a half inch of up and down so it looks like I have to tear the tractor all apart again. This thing is about to beat me down. Been working it since last february and still can't get the bugs worked out. Thanks for the info.

Ultradog MN · Jan 11, 2013

The upper and lower thrust bearing almost never go bad on a PS unit as they are constantly bathed in oil.
I'll bet you dollars to doughnuts that you either forgot or improperly swedged the upper nut
to the shaft and it loosened on you.

Craig Kruse · Jan 11, 2013

(quoted from post at 23:50:39 01/11/13) The upper and lower thrust bearing almost never go bad on a PS unit as they are constantly bathed in oil.
I'll bet you dollars to doughnuts that you either forgot or improperly swedged the upper nut
to the shaft and it loosened on you.

Well I just repaired the leak with a quicky sleeve and didn't tear into the valve body or the housing but I guess I'll find out if the nut is loose when I get in there to see what's going on. I just hate that I have to tear it all apart again after having spent 11 months fixing leaks, finding salvage parts and rebuilding parts and trying to get the thing in a usable condition. I enjoyed the challenge at first cause I like working on mechanical things but I've had as much fun as I can enjoy on this project. If I didn't have twice as much invested as buying a new one I would sell it but I'm in to deep to back out now. Thanks for letting me know where to look for the problem.

Ultradog MN · Jan 12, 2013

Yeah, the worst part about it is pulling the tin off again.
If it were me and I was that far into it I would go ahead and pull the hydraulic block out of it and go through it. Take it apart and clean the rust and crud out of it. I like to wash fine parts like that in lacquer thinner then lightly grease and reassemble. Replace the lower seal while you are in there and both of the Orings - part #s 14 and 33 in the photo below.
Make sure you clearly mark the lines to the cylinders at they can be a pia to sort out if you don't. I use tape and mark them top and bottom.
Be careful not to drop the little springs and plungers in the hyd block as you pull it off the column. They will want to fall out the bottom.
I&T FO-31 manual has a pretty good description of adjusting the spring washer and swedging the nut.
If you get into trouble reinstalling the plungers, etc in the right holes just holler.
We can help.

Jetbird · Jan 12, 2013

Craig, I rebuilt the steering box on my 68 3400. Mine had a broken washer under the nut that is staked to the shaft (#20 in nh parts drawing, they call it a "control valve bearing preload spring"). I think the nut was loose also. You can look up my post on the subject, it may help. My steering wheel had a lot of free play in it, and if I turned the wheel left I think the wheel lifted up towards me. Let the wheel go and it would spin the other way and fall back down on its own. It seems to me that the control valve bearing preload spring is the weak link in this steering box once power assist is lost. The spring is certainly weaker than the tapered roller bearings that stabilize the steering shaft axially (up and down) in the manual steering box. If the power assist is working, the spring doesn't endure much load since the pistons are pushing the wheels back and forth. Once assist is lost, the washer takes a lot of axial force. If yours is broken, the pieces could be loose in your system and could kill your ps pump. I think that is what gouged the body of my ps pump and rendered it useless. Good luck and post back. Oh, and by the way I sympathize. I bought my 3400 for $2600 last July and thought I stole it. Now I have put about $1500 in parts and many many hours into it. Strained relations with the wife, but the tractor finally works and I learned a lot and feel good about bringing it back to life. Don't despair. But if I may suggest, you may want to do something nice for your wife, she probably envies all the attention the "other woman" is getting. :wink:

Craig Kruse · Jan 16, 2013

(quoted from post at 06:33:06 01/13/13) Craig, I rebuilt the steering box on my 68 3400. Mine had a broken washer under the nut that is staked to the shaft (#20 in nh parts drawing, they call it a "control valve bearing preload spring"). I think the nut was loose also. You can look up my post on the subject, it may help. My steering wheel had a lot of free play in it, and if I turned the wheel left I think the wheel lifted up towards me. Let the wheel go and it would spin the other way and fall back down on its own. It seems to me that the control valve bearing preload spring is the weak link in this steering box once power assist is lost. The spring is certainly weaker than the tapered roller bearings that stabilize the steering shaft axially (up and down) in the manual steering box. If the power assist is working, the spring doesn't endure much load since the pistons are pushing the wheels back and forth. Once assist is lost, the washer takes a lot of axial force. If yours is broken, the pieces could be loose in your system and could kill your ps pump. I think that is what gouged the body of my ps pump and rendered it useless. Good luck and post back. Oh, and by the way I sympathize. I bought my 3400 for $2600 last July and thought I stole it. Now I have put about $1500 in parts and many many hours into it. Strained relations with the wife, but the tractor finally works and I learned a lot and feel good about bringing it back to life. Don't despair. But if I may suggest, you may want to do something nice for your wife, she probably envies all the attention the "other woman" is getting. :wink:

Well, You just can't fix stupid. After a review of my past actions and the photo's I took when I took the pump off for over haul because the PO said it was bad I found the first of the two problems with my power steering. I had some help working on the pump and with out adult supervision and careful attention to the diagram in the manual somehow the little valve with the spring on the end got installed backward. The cap with the spring end goes on the ourside or data plate side of the pump. Darn manual didn't tell me to watch out for that one. So after pump removal and turning it around guess what.... mega pump pressure. How do I know? Well the fluid poured out the steering column shaft. Which leads me to the second problem. It seem that when I was putting in the speedy sleeve I installed the seal upside down! Amazing how much fluid can get by a seal installed like that!!! Well luckily I had by mistake ordered an additional seal so I replaced it and put the column all back to gether and amazingly enough I now have power steering!!!!. Like I said you just can't fix stupid just your tractor.

Thanks for all the help

Jetbird · Jan 16, 2013

Craig, I totally sympathize. I do stupid crap like that all the time. One thing I have going for me though: I am too damn stubborn to give up! Good on ya for figuring it out!

3400 Ford Power Steering Question

Craig Kruse

Member

Sean in PA

Well-known Member

Craig Kruse

Member

Ultradog MN

Well-known Member

Craig Kruse

Member

Ultradog MN

Well-known Member

Jetbird

Member

Craig Kruse

Member

Jetbird

Member

Similar threads