Deck issue, lost pin

Sigarms · Jul 4, 2014

Out with the F3080. Since my dad is staying with me, letting him drive it most of the time. He took a break, I hopped on for about 20 minutes. He comes back, gets on, starts mowing, and I have to mention to him to run the engine at a higher speed (he was mowing for about 5 minutes and I noticed he forgot to give it more throttle, that said, he was running for about 60 minutes prior to his water break, no issue).

So?e's out mowing the side of the hill, 5 minutes goes by and I hear a "clunking" noise that comes and goes every 5 seconds or so while he's mowing and I think to myself this isn't good, so I go running over to him (in the meantime, he's noticed the sound as well and stops the mower).

I look around, everything looks ok so I hop on the mower. Running with the blades going at a slower speed, no noise. I then give the mower more throttle with the blades engaged and I hear the "clunking sound" and stop. Looks like it could be a belt (at this point, no clue).

Pull the mower in the driveway to take the deck off.

Deck comes off no problem, everything on the deck looks as it should. I just changed the deck gear box oil about 30 hours previously, no issues.

I noticed however that when I was taking the deck off, I guess what you would call the pin for the lift rod is missing.

The pic above is the drivers left side lift rod, pin still in place. The drivers right side pin is missing (and yet the rod still stayed in place???).

EDIT after thinking about it, I had the mowing deck up pretty high for a tall hot summer cut, so even if the pin/rod did come out, the deck could of been high enough to keep the rod (without the pin) in place?

2 questions

1 How in the heck would that pin EVER come out while mowing?
2 Would missing this pin on the drivers right possibly cause the "clunking" sound when engaging the blades? (I'm not sure how it would).

Thing is, I never took or messed with that pin in the first place. 30 hours after changing the deck gearbox oil (after removing the deck), no problems at all. Pin is no where in or around the driveway, so I can only assume it came off while mowing.

I'm scratching my head right now. No alcohol has been consumed in the last week by the way

I'm open to any and all suggestions.

Sigarms · Jul 4, 2014

The deck in question after being removed. As mentioned, everything looks as it should, or am I missing something?

Belt seems fine with good tension and I just lubed everything up no more than 7 hours previously.

Gator6x4 · Jul 4, 2014

Kubota use a pin with a ball on the end to keep the pin from falling out. I have lost several of the pins. I usually replace with a regular type pin with a cotter key in the end. The missing pin could have allowed the mowing deck to shift or move enough to cause interference in the drive line going to the mowing deck. Also check the universal joints in the deck drive line, one of the joints could be bad.

Coyote machine · Jul 4, 2014

You found a missing pin. Replace it and put the deck back on. Those pins can get caught on branches/similar things while mowing. Use a different type pin to secure it in place if warranted. Check play in U-joints as suggested and keep an eye on Pops, he may be sipping in secret!

LD1 · Jul 4, 2014

For a replacement pin, I would use one of them pins like you used to hold the latch on a trailer hitch. The type with the wire that holds it on. Not sure what its technical term is though....

Sigarms · Jul 4, 2014

Thanks for the input.

All the joints look fine and seem to work along with the belt when moving manually.

Pick up the kids at the parents and FIL had a pin that works, will mount the deck tomorrow to give it a test run and then hopefully pick up some spear pins.

Gator, looking at the existing pin that didn't come out, your right, ball on the other end. It just amazes me that the pin could come out accidentally.

JOHNTHOMAS · Jul 5, 2014

I've replaced the pins on the front wheels of my (maybe even your deck, not sure) deck after the wheels assembly fell off and tire and rim got cut by the mowing deck. The noise it makes when you run over the wheel assembly is pretty loud. I believe the pins break due to the impact of the deck bouncing up and down mowing rough ground. After the pin breaks and your wheel assembly hasn't fell off immediately after the break and you keep mowing and then that wheel goes over a drop/hole that it falls down in and comes out of the hole and you run over it you think it just broke and you can't find the pin. One time it happened to me and the wheel missed the mowing blades and I noticed later the ground was being scalped on one side and finally looked and saw a wheel missing. After searching where the scalping began I found the wheel assembly. I buy hardened steel pins now for the front deck wheel assembly and replace the factory originals. I will now replace the pins on the back hanging assembly with the hardened steel ones. I think I posted here about my lose of wheel assembly when I had to replace the entire tire/wheel one time since the blades cut the rim assembly.
As that deck bounces, it's a really heavy deck with lots of pressure as it bounces across rough terrain, it is putting lots of pressure on those pins. Smooth "lawn" not bad. Rough field/yard lots of pressure on certain points. Some of the pins have rings, like on key rings that turn to keep the pins on. Guess they can be "grabbed" by a limb and pulled out since they aren't really strong.

Gary Fowler · Jul 5, 2014

Did you check the spindle bearings individually with belt loose(just move the idler puller a bit to take tension off) to see if they had play or a noisy bearing when turning them. How about the blades did you check that they are all tight.

Poopdeck Pappy · Jul 5, 2014

I'd suggest a pin like one of these. And if you really like belts and suspenders, you could drill a hole near the end and put a cotter pin in it too.

CountyLine® Lock Pin, 1/4 in. x 1-3/4 in. - Tractor Supply Co.

TailDragon · Jul 5, 2014

Have had retaining ring pulled out on the front deck wheels before, never the ones on the rear deck height adjusters. Have made sure the rings were on the inside for more protection.Did loose a caster wheel on the ZD.
Speaking of front deck tires, both went flat while mowing last week on my youngest F3680, (60 in). I had checked them for give by pushing on them, not using a pressure gauge. Has anyone else had this problem?