At my wits end - replacing front spindle

[Matt in TN]

I have a 1973 Ford 4000 SU (lightweight 3000-type front end), and the front right axle shaft/spindle broke several weeks ago. I've been going back and forth with the dealer trying to get all the right parts and fight 30 years worth of rust and bad previous-owner welding to get everything set. I took the front arm off and to a machine shop to have the old bushings pressed out and the new ones pressed in. I finally went to install the new spindle into the freshly-pressed bushings and found it won't !$#%(*&#$%( fit!!!

Thinking maybe it's supposed to be a press-fit, I stuck it in the 20 ton press and tried to make it fit (probably mistake #1). Needless to say, after 20 tons of pressure I just have a halfway-in and very much stuck spindle that won't budge in any direction.

I've checked and re-checked all the part numbers, and I'm pretty sure the bushings are right. There is still some question on the spindle (there's two versions in the book listed for this model), but I didn't think to mic the shaft and bushings before I started (probably mistake #2). If the shaft diameter is not right it's only off by a few thousandths.

Has anyone on here done this before and can offer some advice? It just doesn't seem like this is should be more than a simple job, but I keep running into difficulty at every single step.

Should the bushings be a press-fit onto the shaft, or should they be a slip fit to have room to turn? I think I can get the spindle back out with a few four-letter words and some more force, but I didn't want to go that route if the right answer is just to push harder and get it to seat all the way.

Any ideas?

 

[Matt in TN]

Just to clarify - these are two models listed for this front spindle as the following part numbers (from the New Holland website):

F2NN3105AA and/or F2NN3105CA

The number on my spindle was almost worn off, but looked to be
C8NN 3107 B. The dealer could not find this number in any of his books, but was all but positive the 3105AA model number was what I needed. Comparing the two spindles shows they are close but I didn't mic either one. There is a difference in the elbow that will give a slightly wider track width, but the angle, length and shaft diameters seem the same.

I don't know if that has anything to do with my troubles, but it's my best bet right now...

 

[IH3444]

First off, pictures would help us see your problem. Second, if this is a king pin replacement, with new bushings, then after pressing in the king pin bushings, a long reamer is needed to final ream the bushing into perfect straight alinement. Then the king pin is either pressed into the bushings, or can usually be driven in with good clean lube grease applied to all parts, and a no nonsense dead blow heavy hammer (lead or brass, some plastic ones will work). If you have tried to press the parts together with out a final alinement reaming, then the parts have to be disassembled. I understand that is where you are now??? Trying to assemble a heavy duty farm tractor king pin assemble without a final alinement reaming is a tough way to go.

 

[Matt in TN]

Follow-up for anyone else having the same problem: IH3444 was dead-on, except I wouldn't really call it a "heavy duty" kingpin (it's the light duty SU/3000 front end). I ended up spending $40 at a machine shop for them to press out the old bushings and press in the new bushings, and then had to take it to another machine shop (1st one couldn't do it) to be reamed to fit for another $45.

I don't blame the machine shops (they both did good work), but I do blame the dealer who sold me the parts. I told him of my interference fit problem and his best suggestion was that the aftermarket spindle was probably machined too big (it measured the same as the old one). The offered to order a New Holland model which would "probably be right" but cost twice as much. He recommended I take a die grinder eek to the bushings until it fit. Nowhere in ordering the parts or in the shop manual did it say anything about final reaming or sizing.

I never would have replaced the bushings if I would have known all this going in - the old ones would have stayed put and probably been fine....

 

[IH3444]

Thanks for the follow up Matt. I was wondering.....glad things went well for you and you got it back together.

 

[Soundguy]

Yep.. ream to fit.. lots of bushings are like that. that way you canmke up for worn spindles..

soundguy

 

[jimmysisson]

I remember being surprised (decades ago) you had to ream new kingpin bushings on cars. I thought they ought to just fit right out of the box. I don't think the manufacturers had quite as good control over forgings, etc, and you couldn't count on the bushings being perfectly aligned. It's satisfying to get all those parts perfect though - you'll be glad you did.
Jim

 

[IH3444]

That's where I learned my lesson Jimmy, on early Volkswagen Beetles, and Mercedes front ends. If Matt would have known this, and the size reamer he needed, he maybe could have purchased the correct size from Industrial Supply Equipment from MSC Industrial Supply. I've found the import reamers for a one time use are just as good as all the others. The are just made mostly in some former USSR european countries. Just measure the king pin, and find a reamer very close, allowing for 0.001" -0.003" clearance. Send the reamer down through the top bushing, and with lots of light oil, rotate it and crank it through the lower bushing. It will usually just barely cut through the lower one, and this will complete the alinement. Then you have the knowledge and tool to do the other side if necessary.

 

[garcer2]

I have a reply for you. I also have a Ford 4000 SU with a bush hog front end loader. my tractor, as well as yours should not have had a front loader put on it because it's too light in the front end; the spindles and axle are from a Ford 3000. Ford did this because the front end would steer better. But it certainly didn't do you or me any favors. Right now I'd trade it for a 4000 or a 5000. I too have gone through several spindles, but on the left side. A few years ago, someone at a Ford tractor dealer told me I could upgrade my 4000 SU to a 4000, but that it would be expensive. How much is expensive? The times the tractor's been down in the middle of a project is more damage to me than what the cost for an upgrade would be. I can't get anyone to tell me, "Okay, these are the parts you need and I'll order them for you and your problem will be solved. That will be $ 1,500.00. Everything will be here in 30 days." I guess they would rather we keep having to buy parts.

 

[Neil Hovick]

I have a 9 n ford tractor. The front wheel spindle broke as I was driving it. I have all the parts but I can not get the pin holding the old spindle in place through that notch out. I broke the nut trying. Any ideas?