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1026R 1025R 1023E 1 series mower setup and adjustment (pre mid-2020)

283619 Views 382 Replies 137 Participants Last post by  Michael Clark
It seems a few owners haven't gotten their new 1 series tractors equipped with either the 54 or 60D mower setup correctly. This will explain how to do it yourself for the best possible mower performance! ;) Most, if not all, of this information can be found in the John Deere Owner's Manuals for the mower and the tractor. 馃摋 The procedure is the same for the 54" and 60" decks, mechanical or independent lift. There is one additional step for mechanical lift-equipped tractors. More on that later...

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First, you're going to need a few tools. A 1 1/8" wrench, a tape measure, or better yet the JD mower leveling gauge p/n AM130907. The tractor needs to be parked on a smooth and level surface for all of these adjustments.


-This step is for mechanical lift-equipped tractors only- To adjust MMM rockshaft lift strap (located between 3PH rockshaft and MMM rockshaft behind the left rear wheel) you remove the mower and remove the hairpin clips and pins (D) to disconnect the lift links (E) from both lift arms. Raise the 3PH fully. Rotate the mower cut height knob to lock position. Remove the left rear wheel. (You might be able to skip this if you can reach the 3 bolts on the lifting strap.) Loosen the three bolts on the lift strap. Rotate mid-mount rockshaft (B) forward until there is a small gap (A) between the height cam (C) and mid-mount rockshaft (B). Move the lift strap forward to the end of the travel slot and tighten the three bolts. (I'd use 1/16" to 1/8" for a goal for this gap.) Reinstall the left rear wheel and mower.

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First, you want to adjust the side lift links (E) for maximum lift. To do this you'll want to start the tractor and raise the mower all the way. Rotate the mower height adjustment knob to the lock position. Now, look at the mower height cam (C) above the left rear mower latch. It's just behind the left rear tire. You want to see a gap at "A". I've found that a gap of about 1/8" is perfect.

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To get this gap set right you first need to unlock all anti-scalp wheels, turn the mower height adjustment knob to the "install" position, and then lower the deck to the ground. Then remove the hairpin clips and pins (D) and adjust both links (E) up equally. Now you need to raise the mower fully and check for the gap (A) between the height cam (C) and the rock shaft arm (B). Repeat this process until you get close to 1/8".

Here is the gap on my tractor. The next picture shows the mower resting on the height cam "lock" position.

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Now we are going to adjust side to side level. Set your mower height adjustment knob to your desired mowing height and lower your mower. Measure your blade height and adjust the same side links to achieve a level within 1/8" to 1/4". I was able to achieve the same measurement on both sides. I usually mow at 3" and marked the scale accordingly.

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After you've set the level side to side, recheck your maximum height setting. Here is my tractor at full travel, mower resting on the lock position, and install position.

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To adjust the front to rear level we'll need your mower at your desired mowing height. Measure a blade from the front and at the rear. It doesn't matter which blade. The optimal setting is 1/8" to 1/4" front lower than the rear. This reduces friction on the rear of the blades and makes the front of the blade do all of the cutting and discharging. The front draft arms will adjust front to rear leveling. First, lower the deck to the install position and loosen the rear draft arm nuts with the 1 1/8" wrench. (The nuts closest to the mower.) It may help to drive the tractor off of the mower just to loosen the rear nuts. Raise the mower back to the desired mowing height. Tighten the front nuts the same amount (it helps to count flats) to raise the front of the deck. Loosening lowers the front of the deck. Double-check your front to rear level once you got the draft arm adjustment nuts tight.

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The Auto-Connect carrier bearing needs to be adjusted for easy connection as well. If you remove the mower it will be easier. Lower the mower/mower lift arms all the way to the install position. There is an adjustment bolt under the bearing to adjust between perpendicular to the ground to leaning ever so slightly forward. I found this makes for the best connection. (I was unable to find anything from JD regarding this adjustment. If you know differently, please post it so this can be corrected)

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Lastly, you need to adjust your gauge wheels for the proper mowing height. In my case, the pin goes into the top hole. That gives about 3/8" clearance between the wheels and the ground.

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Now it's time to go mow your yard and enjoy your tractor! (y)
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The Auto-Connect carrier bearing needs to be adjusted for easy connection as well. If you remove the mower it will be easier. Lower the mower/mower lift arms all the way to the install position. There is an adjustment bolt under the bearing to adjust for between perpendicular to the ground to leaning ever so slightly forward. I found this makes for the best connection. (I was unable to find anything from JD regarding this adjustment. If you know differently, please post it so this can be corrected)
With the tractor on a level surface, place a torpedo level across the face of the autoconnect carrier bearing. Adjust the autoconnect positioning bolt/stop for a plumb indication on the torpedo level. You could probably do this with a framing square, but I believe the short leg would be too tall to fit under the tractor.
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I've read and read... also have several hours in adjustments and yard still looks bad!!!! One thing I haven't read about that mine does is that I can level the deck not sitting on mowing stop and get real close to perfect, mower lifts good and square seems solid! Then I set the stop to somewhere close to 3 inches and the deck sags on the right as much as .75 inches!!! Then I start leveling based on sitting on the mowing stop and the deck lifts wonky and seems to want to sag and twist... Terribly frustrating. Dealer has tried more than once to make it better to no avail....


How old is your tractor and what model? I'm wondering if you have the earlier lift arm/rod that is prone to failure. Your symptoms sure sound like it. See Post #92 in the following thread for a side-by-side comparison of an old, defective, lift arm/rod and the new and improved version.
I understand you can adjust the deck left to right by using the turnbuckles. However, How do you adjust the height of the blades front to back? Should the deck be perfectly level front to back?

Thanks is advance
The front to back height adjustment is made with the large nuts, on the front of the front draft arm, at the front of the tractor.
Well quick update on my experience. My mower height knob would not go past 3.25", no where near 4" or the lock. Looking at the cam it was getting bound up. Had dealer stop over and he was starting to mess with the everything except what he should have been doing. I stop him, bring out the laptop and pull up the PDF file in this thread for mounting mid mount lifting hardware.
Get the lift strap adjusted so there is a gap with deck off, and almost locks with deck on. We discuss the lift strap position with bend inside or outside. He said they come from factory already installed on the tractor. In looking at it I really don't see how it would make a difference in any adjustments as the strap is not obstructed in either mounting position. I thank him for stopping over and pull the big boy in the garage in a nice level spot.

Now, here is where this gets interesting and I see no mention of this in the thread and it maybe should be added. When putting the height adjuster to install, and dropping the deck to the bottom I noticed that I could not remove the pins from the turnbuckles without lifting the deck up off the floor by hand. Obviously the turnbuckles were still supporting the weight of the deck. I recalled that the hardware installation manual said to turn the bolt in the turnbuckle at least half way. Mine were screwed up towards the top with only 5-8 threads showing.

What I decided to do was this: I already had my gap between the turnbuckle and height cam set to about 1/4" without the deck on. I lowered the deck all the way to floor with the guide wheels up. The stamped steel was resting on the cement. I then proceeded to turn the turnbuckles out until the hole for the pin lined up with the hole in the draft bars. They were different on each side, but the deck was fully resting on the cement floor. Once I got the turnbuckles adjusted I replaced the pins, raised the deck and guess what happened? The height adjustment knob went into lock with no issues with about a 1/8" gap. I could then lower the deck into the locked position. I then raised it slightly and the knob rotated freely with no issues.

So now I go to level the deck. Since the cement floor is level I was less than 1/4" off from side to side. One and a half turns on the buckle that was low and it is perfectly level. Front to rear was good and needed no adjusting.

In conclusion I suspect that the tractor had the lift strap on from the factory. The dealer installed the deck, and used the turnbuckles to level the deck without fine tuning it. I suspect a vast majority of people who are having issues with the gap after the strap is adjusted and the deck is on is due to the turnbuckles being screwed in too far. It does state somewhere that if you cannot get to the lock position after the strap is adjusted then the turnbuckles need adjusting. Laying it flat on the ground and adjusting the buckle to the hole may save you from a lot of aggravation and doing this multiple times.\

I did adjust the guide wheels to spec on the garage floor, and the seem to roll constantly on the grass and sometimes support the weight of the deck in uneven spots. But man this thing mowed just as good or better than the 455 I had. No more uneven spots, almost looks stripped. Very happy for this thread and it is worth taking the time to dial it in. I hope my advice on the turnbuckle adjustment makes it in the original post, as it sure did help me.
I would think altering the length of the strap between the rock shafts would have still allowed the deck to rest on the ground, without any weight being carried by the lift linkage. I added jam nuts to threaded rods, that mate with the forks, on both side (to prevent the adjustment from being upset). I have mine set with little thread showing so the deck will be as high as possible when in the "locked" position. I have no issues with them being loose when the deck is in the "install" position. I do have "Independent Lift", but I wouldn't think this would make any difference from "Mechanical Lift".

Now, I do have the thickness of the jam nut, which does set the forks lower on threaded rod. This may equate to what you ultimately set yours for.
Thank you for the assist kylew.

I add a 3/8 fine thread nut, as a jam nut, to the threaded loop, reference item #8 in the exploded view, below:

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I'm away from home at this time, but I'll post a photo when I return. I also label each fork, left or right, with a permanent marker, so I don't interchange them and upset the mower deck height adjustments. Here, in snow country, all that lift linkage in the exploded view has to be removed to install the front PTO shaft required for the snow blower.
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Hi. I haven't read this entire thread since the first few comments along with the manual helped us get the deck set just right (for now). This thing eats wet spring grass like five goats in a chicken coop.

Two questions I have if any one cares to reply...

On my 2018 I believe there is no specific location (label) for "LOCK"?

If the previous statement/question is true, then what is the correct rock shaft position for transport and storage?

You understand I don't want to stress hydraulics more than needed. Thanks in advance.
The dial indicator label was changed starting with the 2018 models. There is no longer a padlock symbol and the label is now numbered. To determine where the transport position is on the dial, you need to adjust the dial so the stepped cam. pictured in the last photo of Post #225, is on the highest deck lift step. That is the transport position.

I took it a step further after setting up the deck height adjustments. I utilized the same gauge to identify the two heights I mow at. In my case, 2" and 2.5". I marked these positions on the dial label with permanent marker index marks. In this manner, I'm always mowing at a consistent height.
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No. The slots are for adjustment only.
The Operator's Manual provides a good, detailed, installation/adjustment procedure. As to the autoconnect coupler:

1. Park the tractor on a level surface.

2. Lower the autoconnect coupler to the "Install" position.

3. Place a torpedo level across the face of the coupler vertically and adjust coupler for a plumb indication.


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