I’m not going to be much help, but I did some quick online googling. Seems like 8210s,8240s,and 8340s all are basically 24” fronts with 34”rears, or 28”fronts with 38”rears. As for the loud whine, that’s normal in my experience. I did have a friend that had a jd 4755 mfwd. Previous owner had...