I've had this 451 for years, bought it used. The push bar arm, the part that has the hole in the front, that the pivot drive assy goes into, has always been loose, like it's been bent towards the front direction. There's at least a half inch of clearance between the front of the pivot drive assy (PDA) and that push bar. It allows the PDA to slide back and forth and makes adjusting the drive bearing for the PDA correctly impossible. So the other day I bought a 1 1/4" shaft collar and put on the front of that pin that goes into the push bar arm. Well, that's taken up the slop there. But my basic question on this part is should that push bar be tight on the front of the PDA? I would think so if the drive bearing is to be adjusted correctly. I find nothing in the owner's manual about this.
Second thing is the Pivot Weld Assy. The other end of the push bar that's under the PTO drive. I can move the outer end of the cutter bar back and forth and there must be 1/4" or more play in that Weld Assy hole where the push bar left side goes through the hole. That results in a fairly large movement of the end of the cutter bar. Is that supposed to be a close clearance? I may have to make pictures for others to see what I'm talking about, I'm using the names from a parts book I have.
Otherwise the mower works great as long as the sections are sharp. I have a lot of banks and tree lines I can get under with it that the bushhog can't. Plus it cuts a solid 7' each pass where the 5' BH maybe cuts 4.5' at best and the sickle bar cuts better. The BH just beats stuff like a large hammer. I can cut fields with the sickle bar in half the time of the BH and it's easier on the tractor. Plus I'm not driving through a lot of overgrown grass once I make a single cut around the perimeter. The fields have never looked so good since I got the NH, and gotten rid of the horses and cattle. I try to mow 3 times a year. About 14 acres in 4 fields, 5, 7, 1 and 1 acre each. Very hilly in the foothills of the Blue Ridge.
Second thing is the Pivot Weld Assy. The other end of the push bar that's under the PTO drive. I can move the outer end of the cutter bar back and forth and there must be 1/4" or more play in that Weld Assy hole where the push bar left side goes through the hole. That results in a fairly large movement of the end of the cutter bar. Is that supposed to be a close clearance? I may have to make pictures for others to see what I'm talking about, I'm using the names from a parts book I have.
Otherwise the mower works great as long as the sections are sharp. I have a lot of banks and tree lines I can get under with it that the bushhog can't. Plus it cuts a solid 7' each pass where the 5' BH maybe cuts 4.5' at best and the sickle bar cuts better. The BH just beats stuff like a large hammer. I can cut fields with the sickle bar in half the time of the BH and it's easier on the tractor. Plus I'm not driving through a lot of overgrown grass once I make a single cut around the perimeter. The fields have never looked so good since I got the NH, and gotten rid of the horses and cattle. I try to mow 3 times a year. About 14 acres in 4 fields, 5, 7, 1 and 1 acre each. Very hilly in the foothills of the Blue Ridge.
