John Deere 755 doesn't move

[Greg-N-CA]

A friend's 755 wheel tractor stopped moving last week. All hydraulic components are working, but it will not move when pushing on the forward pedal. It will move VERY slowly in reverse, but without any power to speak of. This all started a couple of days after installing the backhoe attachment.

I've checked the oil level and if anything it''s over full. I will change the hydraulic/transmission filter today to see if that helps.

Any suggestions?

 

[Rusty wheel]

My 325 did the same thing. Turns out the pully on top of the transmission was slipping cause the spline was worn out. The pump shaft is steel but the pully is aluminum.

 

[F-I-T]

Well, the hydraulics function because it has its own pump....just above the rear power take off. The two systems share fluid and filter, but have separate pumps.

No aluminum pulley in this system. The engine to pump is a drive shaft that has to be right. It has u-joints, but since it runs true and at engine speed, they rarely fail.

Did he tap the back hoe in correctly, using the hydraulic system through a power beyond tap? I can't think of a way to tap the drive system without jinkin into the pipes under the floor cover.

The forward/reverse motion is controlled by the pedals moving a lever on the right rear side of the hydraulic motor. The linkage is simple, but it is possible for it to foul or bind. There is also a vertical safety stop rod that gets depressed when you sit on the seat. I would look at that area in case the back hoe mount is trapping that rod in the up position. That would limit the total movement of the pedals.

 

[BoonvilleKid]

F-I-T, you've pointed out a situation that can be one of the causes of this type of operation. The seat sets down on a rod that has a cam on the end that permits or prevents the forward/reverse motion of the tractor. It's just a safety device. But, it has to be adjusted for the weight of the operator. I own (2) 955's that have the same setup. As you've pointed out, installation of the backhoe may have interfered with the operation of this linkage as their had to be modification to the hydraulic system for the backhoe system - or, at least I had to when I installed my backhoe. Lifting the seat and making sure the rod works correctly will either find or eliminate the possibility.