4500 steering problems
As far as the piston rod end being broken off, I had mine welded back on and then had the shop clean up the weld on the lathe so I could maintain the piston travel. Take it to a shop that specializes in hydraulic cylinder repair. It will be worth the extra time to get it done right. New parts are WAY to expensive. They come out of the Ford/New Holland parts museum inventory somewhere in tractor heaven and are priced accordingly. Aftermarket parts are cheaper but the quality varies widely. When you reinstall the cylinder make sure to shim the rod end up properly on the connector pin where it attaches to the front casting or it will bind on the pin and break off the piston rod end again.
The pin which attaches the cylinder to the steering arm is a tapered fit and required heat and a hydraulic jack to get it to pop loose. My previous post describes the difficulty I had getting the pin out of the front casting. The main steering arm pivot pin is locked in with a big bolt. After you get the keeper bolt out there is a threaded hole in the top of the pivot pin where you can thread in a puller bolt to lift the pin vertically out of the hole.
There is a reason you don't see power assist hydraulic steering cylinders like this anymore. They don't work so good when there is wear in the linkage and require everything to be tight and new to work as designed. In addition the repair manual covers adjustment of the Ford 4000 power steering system which has built in travel adjustment but only peripherally covers adjustment of the 4500 system. This is because the 4500 system has no travel adjustment between the steering arm and yoke. It was not designed to survive this long.
After all the fixing I did on my 4500 steering system it worked OK but it would pull to the left and when the front wheels came off the ground, it would start hammering - fluttering. I was afraid the hammering would break off the end of the steering cylinder rod again which would have put me back to square one again. After much cogitation, I finally decided that the hammering was caused by excessive wear in the pin and socket connection between the main steering arm and the actuator yoke, which attached to the cylinder.
The way this steering system works, is that you have the yoke attached to the main steering arm by a pivot pin. The yoke is held in place on the steering arm by a cotter pin through the pivot pin. There is a socket hole in the yoke a couple of inches away from the pivot pin in which travels a pin which sticks up from underneath from the steering arm. As the yoke is pulled on by the pitman rod, it wants to turn on the pivot pin on the steering arm. It turns a little, but the pin and socket connection only lets it move a small amount. Since the back of the cylinder is attached to the steering arm and the yoke is attached to the valve, it is the small rotation of the yoke in relation the steering arm that moves the valve back and forth. When everything is new and tight, a little movement from the steering wheel moves the yoke in relation to the steering arm and causes the steering valve to try to “catch up” to the yoke. Sadly the maximum travel for the valve in and out is less than 1/8th either way. If the hole and socket becomes excessively worn the valve gets moved to far one way or the other and it starts to malfunction.
Hard as it may be to believe, I was able to remove the power-steering pump and drive shaft and then the cylinder yoke without tearing everything back apart. Since I had already reinstalled the radiator and shroud/hydraulic tank, I was not about to take it all back apart without looking for another solution. The air cleaner was still off at this point so I had that much room to work with.
In order to work on the yoke I had to get it off the tractor once again. This required removing the tie rod back to the steering box. However, I had to use oxyacetylene to heat the casting around the pitman ball joint to get it to pop out. It took a lot of twisting and turning of the parts but I eventually was able to get the yoke back off without tearing everything back apart to check out the hammering problem. It all finally came apart and I was able to remove the parts from below behind the axle or from in front without pulling the radiator.
After measuring the hole in the yoke and pin in the steering arm in both directions I found it was out of round about an 1/8th. I then looked at how much travel the cylinder valve actually allowed and it was equal to or less than the play in the hole. Since there was more travel in the linkage than the valve would allow, it was bottoming the valve and making it hammer.
My Solution:
I drilled and tapped a hole in the yoke at the side of the socket hole where it met the pin in the steering arm for a 5/16 allen head bolt. I also made a steel bushing out of a soup can to shim the pivot pin-hole connection where the yoke rotates on the steering arm. By using the tip of the allen bolt as the point of contact I was able to effectively eliminate the wear in the pin and socket and therefore eliminate the hammering. It still pulls to the left a little but I was able to adjust most of that out with the turnbuckle on the cylinder. The left pulling problem is an internal leak in the valve, which will just have to wait for another day to be fixed.
