GC2300 transmission problem

[feez26]

I was mowing a wet area with my GC2300 and was stuck. Engaged the rear differential lock and still couldn't get out. I put it in neutral and pulled it out with my truck. Now it seems like the rear differential lock is still partially engaged. I jacked up the tractor and pushed the pedal down and the right tire spins a LOT slower than the left. Any idea what's wrong.

 

[whis]

can you hold one tire, if one is turning slower differential lock is not working