Lefty, since you said it appears that someone adjusted the control linkage, I would say it is possible that you could also just have another problem. Mitch is right in that these dry clutches do tend to rust the clutch plates together if they sit up for a while, so it could very well be that. But your symptoms also sound like it could possibly be a bad adjustment. Please read post 1780 and others on page 119, in which I posted some pictures related to these adjustments.
Basically, the way it is supposed to work is when you pull back slightly on the steering handle, a plunger on the steering control valve assembly is the first thing that is actuated. When it is pushed in, fluid is routed to the steering booster cylinder, which drives it forward and actuates the clutch release, which causes the drive on that side to quit driving the sprocket on that track. It is basically free-wheeling at this time and the drive on the other side will gradually turn the dozer in the direction of the handle that was pulled.
When you pull back harder on the handle, it actuates the steering brake on that side, which stops the sprocket from turning at all, and the dozer will turn sharply in that direction due to the other track being the only one moving.
If the linkage is out of adjustment, what can happen is that the brake is actuated before the plunger is pushed in to release the clutch. So you have the clutch engaged, trying to drive the sprocket, and the brake engaged trying to stop the clutch from turning the sprocket. This causes the engine to want to stall as it hasn't enough power to override the brake, and it just bogs down.
It is pretty hard to troubleshoot this without pulling the seat so you can see the plunger and the brake lever and make sure they are being actuated in the right order. If I were you, I would do as Mitch suggested first, and try to break the plates loose. If that doesn't do it, I would pull the seat and take a look. And keep in mind that just because the plunger is pushed in doesn't mean that the valve is working and actuating the booster cylinder. There could be a problem in the steering valve control assembly or booster cylinder, although I think these are rare.
I do know for a fact that if you are really low on fluid in the main clutch compartment, which is where they get their fluid, the steering valves will have nothing to send to the booster cylinders, and they will not actuate at all, resulting in the clutch engaged and the brake engaged when the handle is pulled back hard, and the engine will bog. I had this happen several times when I had a bad oil leak and it ran low on main clutch fluid. Adding oil immediately made it start steering perfectly again. I don't think this is your problem though because you said one side steers ok, but the other causes the engine bog. I was getting it on either side when the fluid was low.
I wish you luck with it, and please let us know what you find. The more solutions we hear about here, the more we all learn.
