gear shift on a 475DI

[casinocop40@excite.com]

Can someone tell me what may be the problem with my shift lever? I cannot shift the tractor into 4th gear. It's like there is no gear there anymore. It use to work fine and now it's like hitting a stop or something. Is this something I may be able to correct myself? The nearest dealer is over 100 miles away and I don't have a trailer to haul the tractor.

Thanks for any help