CAT D4H WON'T MOVE

Hi, I recently purchased an 89 cat d4h and am new to heavy equipment besides farm tractors. The guy that I bought it from said that the transmission had been rebuild about 3 yrs ago/less than 100hrs ago. S/N 8PB03682. He wasn't a believer in maintenance and it sat for about a year, so i changed oil and all filters on the machine and pb blasted all linkages. I had worked it 1 day, and the next day I was cutting in a driveway when i heard a pop, not real loud, just sounded like it popped...

CAT D4H WON'T MOVE

CAT D4H WON'T MOVE