We have a 340 ground driven cart and just wondering why our back tank applying Urea is having issues while the other 2 tanks are ok. It always seems to over apply, I always calibrate then re cal after 15-20 acres. Target rate was 175 pounds and had a weighed amount of fert in the trailer and it put on 200 pounds. I've done mulitiple 1/10 of an acre checks and it always seems to vary each time. You will get a few at 175 pounds and then will get a 200 pound one out of the blue. Is it just the way the Urea is flowing through the tank or am I missing something. I did a transmission swap between tank 2 and 3 and its the same. I am stumped.