Suburban Plowboy
Platinum Member
I finally fixed the right rear scalp wheel on my ZD326. At some point before I bought this thing, all 4 wheel pins seized in their bores, which Kubota stupidly made too tight. This applies to other Kubota decks as well. A number of people have had their pins bind.
The pins on the rear of my mower are about 0.990" in diameter, and the bores are not much bigger. The pins were originally coated with something resembling cadmium. Kubota did not coat the bores, so there was bare steel against plated steel.
Kubota's engineering was beyond stupid. Because the pins are metal, water condenses on them. Because they are vertical, the water runs down into the bores. Because there is nothing to prevent rust, the bores rust. Because rust takes up more room than steel, the bores get tighter. Because Kubota stupidly made the bores tight, this causes immense pressure to build up, gluing the pins to the bores. Even a tiny layer of rust will lock them up solid.
My pins would not yield to a sledge, an air hammer, a torch, or a three-foot pipe wrench. Penetrating oil went in but did nothing.
I drilled one pin out. I drilled and then sawed from inside. That was dumb. It took forever, damaged my drill, and made my back hurt for days.
I got smart with the second pin. I cut the support off the deck and put it on the 20-ton air-over-hydraulic press. I didn't have a proper jig, so I sat it on a big impact socket. The press labored, but it moved the pin a little. I kept reversing it. When it loosened up, I went to the arbor press and then a sledge and punch. Finally got it out.
This may be the best way to get stuck pins out. Anything that resists a 20-ton press is not going anywhere with lesser tools. Even after my first pin was hollowed out, a sledge would not move it.
The rust was very light. Kubota made the bores tight for no reason, so these pins will seize badly with nearly no corrosion. John Deere has made decks with pins that can't seize. The amazing secret: clearance.
Today I welded the support back on the mower. I'm not happy with the welds, but they will work well enough to allow me to remove the deck from the mower so I can get room and light to do the job better.
The new pins were about $50 each. They are chromed, and Kubota did such a bad job, the chrome has bare patches that rusted before the pins were even out of the factory. I am considering turning them down a few thousandths and plating them with zinc.
The horizontal adjustment pins also seize, so it's probably smart to open up the adjustment holes.
You can prevent seizing by applying anti-seize over and over during the life of your deck, or you can be one of the lucky ones who lives in a dry area or who moves the pins so often they can't seize.
Kubota's engineers get an F. Second major problem with this mower. The ECM, which it never needed, died, and now this. It's strange how such a great mower ended up with two huge flaws.
Now I need to fix the fuel tanks so the mower runs on both at the same time.
The pins on the rear of my mower are about 0.990" in diameter, and the bores are not much bigger. The pins were originally coated with something resembling cadmium. Kubota did not coat the bores, so there was bare steel against plated steel.
Kubota's engineering was beyond stupid. Because the pins are metal, water condenses on them. Because they are vertical, the water runs down into the bores. Because there is nothing to prevent rust, the bores rust. Because rust takes up more room than steel, the bores get tighter. Because Kubota stupidly made the bores tight, this causes immense pressure to build up, gluing the pins to the bores. Even a tiny layer of rust will lock them up solid.
My pins would not yield to a sledge, an air hammer, a torch, or a three-foot pipe wrench. Penetrating oil went in but did nothing.
I drilled one pin out. I drilled and then sawed from inside. That was dumb. It took forever, damaged my drill, and made my back hurt for days.
I got smart with the second pin. I cut the support off the deck and put it on the 20-ton air-over-hydraulic press. I didn't have a proper jig, so I sat it on a big impact socket. The press labored, but it moved the pin a little. I kept reversing it. When it loosened up, I went to the arbor press and then a sledge and punch. Finally got it out.
This may be the best way to get stuck pins out. Anything that resists a 20-ton press is not going anywhere with lesser tools. Even after my first pin was hollowed out, a sledge would not move it.
The rust was very light. Kubota made the bores tight for no reason, so these pins will seize badly with nearly no corrosion. John Deere has made decks with pins that can't seize. The amazing secret: clearance.
Today I welded the support back on the mower. I'm not happy with the welds, but they will work well enough to allow me to remove the deck from the mower so I can get room and light to do the job better.
The new pins were about $50 each. They are chromed, and Kubota did such a bad job, the chrome has bare patches that rusted before the pins were even out of the factory. I am considering turning them down a few thousandths and plating them with zinc.
The horizontal adjustment pins also seize, so it's probably smart to open up the adjustment holes.
You can prevent seizing by applying anti-seize over and over during the life of your deck, or you can be one of the lucky ones who lives in a dry area or who moves the pins so often they can't seize.
Kubota's engineers get an F. Second major problem with this mower. The ECM, which it never needed, died, and now this. It's strange how such a great mower ended up with two huge flaws.
Now I need to fix the fuel tanks so the mower runs on both at the same time.
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