Caster setting for a farm tractor

So ive been mentioning in my tractor build thread that my factory steering is shot. The gearbox is bad, the spindles are bad, its just all bad. Replacement parts are hella expensive, and from what ive read online, even when everything works its not very good. Its manual steering and when you consider it will have loader, well its just really bad. I dont want to spend thousands to have steering that sucks. So im going use steering axle parts from a combine to go to full hydraulic steering. I have a plan in mind for the install that will take some welding and fabrication. What caster should i have? Does it even matter with full hydro? I dont know if that type of steering even has a return to center the way a normal setup does. Any thoughts? Thanks

I'd say about 2deg, just enough for a little caster effect. This is about the minimum you'd see on a production car (pre-PS cars with reverse caster excluded).

I don't think you want very much (if any) with a front end loader. Caster is for stability. This is a tractor.

Just a couple degrees would be good. Just enough to keep things stable if you do drive the thing down a long driveway or something at 10 - 15 mph. But it doesn't need much (and you don't want the high steering effort and weight jacking that significant caster will cause).

I think the biggest reason NOT to run much caster with a front loader is that if you a run too much, once the steering goes off center the weight on it will be trying to ADD steering angle. If it were a car with wide square shouldered tires, the weight jacking effect would counteract it. But, if your tires' cross-section is pretty much circular than there's not much to counteract the fact that the more steering angle you have, the closer your spindle gets to the ground. Extra weight being carried in the loader may make the steering UNstable. So i'd run close to zero.

This all sounds legit. Ill try to check a few modern 2wd tractors to see how the factory does it as well. Thanks

Whatever happens, make sure your caster doesn't go negative. My dad had a 1937 Toro that had a worn out front pivot axle mount, causing the kingpin axis to slant forward. The tractor was always trying to go random directions, randomly. The only good thing was that, when driving on a side hill, it would actually try to turn up the hill. It was terrifying under most conditions, though, because it was a very fast tractor.

Its not a proper old tractor if the wheels aren't doing the funky chicken going down the road.... Anyway that's why you have the independent brakes