First of all I will say to you all that I appreciate all your comments very much. It is very nice to have them and it also show me that there is an interest for my project. Thank you very much.
I have now read some articles about KPI (king pin inclination) and I now understand your concern.
I must admit, that when I did the front spindle upgrade, I didn’t know much about steering geometry, but know I got a little wiser after reading the articles.
When I did the upgrade I simply copied the angles from the old spindles to the new spindles.
Here you see the original spindle and the upgraded spindle. The angle x = angle y
Here is a picture of the front wheel taken from the front of the tractor. If the scrub radius should have been smaller the angle y has to be bigger or the spindle has to be shorter.
As you can see here there is only 13 mm (½ inch) from the tire to the spindle bracket, so the spindle is as short as it can be. I could have mounted the spindles higher on the bracket so that it could go inside the rim, but then the nose of the tractor would come closer to the ground.
It is a pity that we didn’t talk about all this before I made the upgrade. But now were it is done, I will give it a try and see how the steering works in practice. It’s probably also about having a little feeling with the force you put to the steering wheel and when things will break. If I can’t turn with a full load I have to reduce the load and drive twice.
The next step would be to upgrade to power steering as suggested by twostep. This would then be a new project and new post.
Edited by Per, December 14, 2012 - 05:14 PM.