I currently run an older 450c on the farm and I'm about to break down and do some brake and and other work on it so it lasts another couple of years. As an alternative to finding someone to work on the 450, I see a D3B for sale in PA about 100 miles from me and am considering replacing the Deere machine with the Cat. I think the D3 has dry clutches and and pedal steer [new to me] but looks in good shape from pictures. I hear they had brake issues with a cam or sprocket in the internals but haven't found anything yet to tell me how much of a mess it would be to work on brakes on that machine. In the opinion of those of you who care to comment, -am I upgrading or stepping backward with the idea of replacing the 450 with the D3. I imagine it will cost about half the asking price of the D3 to get the 450 to the same standard of repair. I have an old D4-7U that I parked years ago and remember that as pretty rugged old machine but I'm not sure how the newer versions stack up to the old iron.
They are pretty comparable machines. I did the steering clutches and brakes on the loader version of a D3B with dry brakes. 450C has wet brakes so a little better in that regard. Have heard 450C transmissions are very costly to repair. Don't hear of many transmission issues with D3B's and they are a little simpler. D3B's could have 1 reverse or 3 reverse transmission. Would really need to have the machines side by side and run them both. You might be better off knowing what you already have instead of getting into a whole new can of worms.
I agree with Dave, unless you have a good relationship with the D3 owner and trust he will give you a good idea of what that machine is like, the machine you know is probably better than the machine you don't. jmho.