Drumming up this old thread in hopes it may help others.
I replaced my rock shaft and lift arms on 04/21/24 to fix the leveling issue that I was having, per the recommendations in this thread.
My machine is a 2014 X734, with a 2014 60HC deck, serial number 021097. Your mileage may vary depending on model, year, and deck serial number.
I ordered the parts for serial numbers 042351 and higher, which are technically not the correct parts for my deck, but they do fit and work with some mixing of new and old parts that I will explain in another update on this post.
The part numbers for serial numbers 042350
and lower, are listed further down this post.
These parts are for 60HC Deck Serial Numbers 042351 and higher:
1 - AM148019 Mower Depth Control Shaft (rockshaft)*
1 - M177097 Mower Depth Control Lift Arm (Left)
1 - M177098 Mower Depth Control Lift Arm (Right)
2 - 19M7786 Hexagonal Head Flanged Screw, M10 X 30 (the bolts that go into the end of the shaft to hold the lift arms on)
2 - M177356 Countersunk Head Screw, M10 X 112
*note this rock shaft has right hand threads on both ends, so you'll need at least 1 of the 199M7786 Hex Head Flange screws. The old rock shafts had a left hand thread screw on the left side, and a right hand screw on the right side. You can keep the same screw for the right side, but the left will need to be replaced with this new part number.
Here is a side by side comparison of the old lift arms vs new lift arms:
Top view: old on the left, new (M177098) on the right.
End view: old on the left
Side View
Better image of the wear on the old lift arms (below, left side arm). Holes are a bit rounded in the corners. I'm pretty sure that the original shaft was probably ok, it was just the slop created when the corners rounded on these older lift arms. I put them on the old and new rock shaft and there was a considerable amount of play, especially on the left side. I could wiggle the arm forward and back with at least a 1/2 inch of play at the end of the arm. This, spread out over the width of a 60 inch deck was considerable. The gentleman from the facebook group mentioned below in the instructions for serial numbers 042350 and lower, said that he kept his original rock shaft and replaced the lift arms with the parts recommended for his serial number, and that fixed the issue for him. I probably could have done the same and saved the cost of the newer arms and rock shaft.
Old and new Rockshaft comparison. Old on top, new on the bottom.
Old and new parts shown together
These parts are for 60HC Deck Serial Numbers 042350 and lower:
1 - AM145479 Rockshaft
1 - AM145339 Mower Deck Control Left Side Lift Arm
1 - AM145340 Mower Deck Control Right Side Lift Arm
2 - 19M7786 Hexagonal Head Flanged Screw, M10 X 30 (the bolts that go into the ends of the shaft to hold the lift arms on)
Here is a picture of an original lift arm (on the left) next to the newer lift arm (on the right):
(image credit from a fella in the Facebook group "
John Deere 2006-Current X700 Garden Tractor’s")
