Bought a used Mud Hog rear axle come off of L-2 hydro differant in l 6x6 in L-2 Lis 6x4 need to know where the f-r charge line on 6x4 hydro any info would be great, tried talking to mud hog talked to a real idiot there I think he didn't want to help also tried AGCO service help they also was little help,the service manual really don't tell anything either so any help would help TIA Marty