8N steering box adjustment

I am new here and I hope I am doing this right. I couldn't figure out how to search the archives, so I will just ask my question. I have a 1948 8N. I am rebuilding the steering gearbox. It's the gearbox that has the sector shaft housings that you rotate to take out the backlash. I replaced and reamed the sector shaft bushings, I replaced all the bearings and put in a new steering shaft with a new ball nut. The old shaft was bent slightly. It wobbled some at the top of the tube as you rotated it. The manual says to rotate the housings to take out the backlash as you assemble it. I took out the backlash and then backed off by loosening it to the first set of bolt holes. So now, when I rotate the steering wheel there are intermittent places in the rotation where the steering is hard to turn and places where the steering is easy. The only thing I can think of is that somehow the shaft must somehow not be straight between the bottom and top roller bearings where the ball nut travels or the screw channels where the balls travel are not true. Am I asking too much out of this ? If I back off by rotating the sector shaft housings to loosen thing up, that results in significant play in the steering. I can return the worm shaft and ball nut, but I don't want to do that if nothing is wrong with it. Is there anyone who can suggest how I should proceed from here? Maybe there is something else I can try or check, but I don't know what that could be. Thanks a lot for any suggestions you might have.

If all that is wrong with your old part is that it has ''a slight bend'' near the top of the shaft I would straighten it and put it back in vs. mucking around with today's parts, likely made in ''The land of Almost Right''.

Thanks a lot wore out. Thats what Im thinking
about. I have never straightened a shaft before,
however I do have a press and have watched a couple
of videos, so I might try it. Does it sound to you that
there might be something wrong with the new shaft?
Thanks again for your response.

(quoted from post at 09:19:12 04/25/23) Thanks a lot wore out. Thats what Im thinking
about. I have never straightened a shaft before,
however I do have a press and have watched a couple
of videos, so I might try it. Does it sound to you that
there might be something wrong with the new shaft?
Thanks again for your response.

Click to expand...

It certainly sounds like something is not right with the new shaft, perhaps the ''rack'' wasn't machined exactly right.

On the other hand, could it be the mix of used and new parts that could affect how they mesh together?

That is a good question about new and old parts.
Hadnt thought about that. Ive decided to try
straightening the old shaft. Hopefully I wont have to
go through too many attempts to get it reasonably
close so I dont have to keep installing and
reinstalling to check it. Thanks for your help wore
out.

Welcome aboard Bill, but there is a separate forum for the FORD N-Series models that'll get you more exposure to others with Fords and better answers your questions. The 8N used two different steering boxes, early and late, so don't rely on whatever your s/n is or what someone told you, and parts don't interchange. Yes, you correctly ID'g the early box but if you were sold the wrong parts, may have issues. John Smith once told me after rebuilding/restoring an early 8N box if he had to do it all over again he'd get a later box and slap it in. The later boxes were better. Are you using the I&T FO-4 Service Manual, Dealer Training Service Manual, Operator's Manual, and Master Parts Catalog as your guides?


1948 FORD 8N TRACTOR, w/ EARLY STEERING BOX, USED 47-49:

LATE 8N STEERING BOX, USED 48-52:

FORD 8N TRACTOR OPERATOR'S MANUAL, EARLY 48-50:

1949 DEALER SERVICE TRAINING MANUAL:


I&T FO-4 SERVICE MANUAL:

FORD N-SERIES TRACTOR 39-53 MPC:


Tim Daley (MI)

Thanks a lot Tim for all the references and the great pictures. Im using the FO-4 and one of the early service manual. The FO-4 says to adjust until the backlash is removed and then it says to overhaul the unit if excess backlash still remains, but it doesnt define excess. With the new shaft I know it was excessive because if I tightened it any more the steering became intermittently hard to turn as I rotated the steering wheel. I did manage to straighten my old shaft to take out all but a slight run-out at the top of the tube and I was able to get all but a slight bit of backlash out of the left side. The right side has just a slight bit more backlash and the steering is fine throughout the entire rotation. I think its probably hard to say whether or not the new shaft is defective or the problem has to do with trying to make a new part work with old parts. Getting back to the adjusting, I noticed that the part of the owners manual you sent me says the minimum backlash that will not cause hard steering is the desirable adjustment. I would interpret that as to mean an amount of backlash that is reasonable, and that would have to be based on experience, not much of which I have. However, I think I have just enough to know Im ok with what I ended up with by using the old shaft. I am going to check out the other part of the forum more dedicated to 8Ns. Thanks again for your help, Bill