Case 485

[NUTTERDW]

I have a Case 485 that has about 1000 hours on it and the differential lock is stuck. I have put around 100 hours on it over the past 15 months. The hours appear to be right because it had the original tires on the rear. First thing I did was replace them because I could see the tube in the side of one. I have sprayed the linkage numerous times with penetrating oil but no success. The pedal will move slightly but nothing else moves. I have guessed that the problem is in the linkage but I'm beginning to wonder. could it be in the lock itself. Any helpful ideas would be appreciated. I plan to strip the tractor down and paint not and then I can get a better look at the linkage