ford 1210 4x4

P.S. anybody have any info. on old studebaker cars & trucks for sale?

If you are new to tractors and it has HST, the speed pedal isn't like an accelerator on a car. It's more like a continususely variable transmission. Slow speeds are low gears. Operating on anything like 45-degree slopes likely isn't recommended and there are severe safety issues. It'd be good to read about tractor stability and ballast.

There may be nothing wrong with the tractor but just that it isn't designed for that great of slope and speed. Too great of a load on an HST and the relief opens. The load can be reduced by using low range and going slow by reducing the speed pedal. I'd also check to ensure the brakes aren't dragging and I'm assuming the engine is run at PTO RPM. If that doesn't manage the problem a New Holland dealer could perform a pressure test to see if the relief setting is low. There may be other explanations for the howling as well or it may be normal. In general tractors aren't intended to work on 45-degree slopes for mechanical and safety reasons.