i just got my 1755 out that I bought that i have been working on etc.(brakes, rebuilt pto, and tlc). I was heading to the farm with it and had to pull a short somewhat steep driveway to my mom and dad's house. I was in 5th on the stick but can remember if i was in direct,over or under. I was somewhere around 1800 rpm and a vibration was felt. I was not  sure if this is a problem or if this is the nature of the beast. Later the next day pull a 10ft. 3pt ripper in 3rd and did not notice any kind of problem. Any Ideas??? Thanks for the help.