I had great success freeing up a stuck steering clutch using kerosene.I put a gallon in the chamber and drove the D2 around.I didn't soak the clutch,just drove it.In the beginning I had basically no steering clutch action.After driving the D2 around up and down hills,the steering action gradually returned.I engaged and disengaged the clutch a lot assuming that would aid in circulating the kerosene over all the clutch parts.I drained the chamber and collected ugly brown fluid containing a fair amount of grit and sludge.I repeated the process a couple of more times,and now the clutch works fine.Steers without applying the brake.Light brake pressure stops the track.I had tried something similar using diesel oil,but without near as good results.
Or if you're feeling really lucky, then get another of those "running when parked" D2's!
Other folks haven't been so lucky with the procedure.
You will want to check that the kerosene hasn't invaded the final drives or the bevel gear compartment in any significant amount and also re-lubricate the clutch release bearings (whichever type you have) before you run it a lot. The kerosene may have washed out all the lube in those bearings.
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time😄