I have a early 70s JD 544 that I bought from an equipment auction. originally I thought that the engine was week (non-turbo) but now I had the transmission go away as if it were a standard shift with a clutch slipping any help would be appreciated.
I used to own one of those. The first thing to check is fluid level and filters. If you haven't changed the filters to that first and possibly the fluid. Does your machine have a trans. pressure gauge on dash? If so, does it show pressure when it slips?
Check the rubber biscuits on the back of engine if it just quit all at once and you will usually smell rubber when this happens. Those Allison transmissions and that's what john deere was using back then were also known for the suction tube getting a crack where it had a mounting bolt bracket inside the case.