New to forum- International 150 track loader help

I am in the process of buying 10 wooded acres next to me that i will need to clear. My neighbors FIL owns the 150 power shift, and has offered it to me for free. Going to look at it in a couple weeks. He says it runs good but the last time he used it (about 2 month ago) something in the transmission started rattling or clanking. So he took it back to the barn and parked it. He went out this weekend and tried to move it and said it wouldn't go in gear. He thinks a linkage might have come loose. Is this possible? What should I look for? I know nothing about track loaders or how the power shift works. I have operated other types of equipment before. I would have to pay someone to haul it 250 miles to my place so I am concerned it may cost a fortune to get it running. Any guidance or suggestions are
greatly appreciated.

New to forum- International 150 track loader help