Mold and grass buildup on mower deck underside

[WinterDeere]

Yes, mulching decks are almost always worse than standard side-discharge decks, when it comes to clogging with grass.

But I mow wet and damp grass every few days for months at a time, since those are our local conditions, and never have an issue with clogging. If you do, I suspect you’re letting the grass get too long between mowings, which both gives it more opportunity for interlocking “structure”, and also might be bogging your deck speed down too far for it to properly eject.

Wet grass will stick in every possible inaccessible corner of your mower deck, but should never interfere with the deck’s ability to operate, at least in my experience. That wet gunk will dry into plaster between mowings, and then fall out making a mess and a racket when you hit a hard bump next week.

 

[DHD]

I use to own Wheel Horse garden tractors with belly mowers and had the same grass clipping build up and mold. It was difficult to clean out the built up clippings with the deck attached and a hassle to remove and reinstall the deck after each mowing just to rid the deck of clipping build up.

I now own riding mowers with front mount, flip up mowing decks and clean out built up grass clippings after each mowing session. (Husqvarna R322T AWD) It takes about 15 seconds to flip up the deck, to have easy access to clean out those grass clipping. It's also much easier and quicker to change out mower blades.

 

[walnutman]

Age old problem. One thing I got away from years ago is bagging. I get it with a small lawn that's manicured. Had a neighbor when I lived in SE PA that bagged his 1/2 acre and dumped it in a pile in the woods on MY property LOL. Over the years that pile got huge.
Also don't mind dandelions. To me they are edible, great for bees and are really just wildflowers.
I run a Ferris 61" ZTR. Love the suspension on it. Sold an Exmark after a year to save my kidneys.
I have the HF mower lift. Works well but I do put jackstands under it for safety.
Grass grows like crazy here in East Texas and rains are unpredictable. I just try to get it cut before the rain.
I mow about 3-1/2 acres once a week.
Clean the deck with a putty knife prob every two or three cuts.

 

[POGuy]

I try my best to only cut dry grass, but even dry grass has a decent amount of moisture in it. Tried the deck wash part on deck, really didn't work. I found myself lifting and fast releasing so deck would hit ground hard to dislodge clumps with water running. Easier and cleaner to raise deck and scrape with putty knife.

Here in Louisiana we also have the added fun of crawfish chimneys which are about 3-4 inches in diameter with a 1 inch hole in the center and 3 to 8 inches tall, so in addition to waiting for wet grass to dry, sometimes you would have to wait for the chimneys to dry. Adds a lot of mud to the clippings under the deck. So much so, you can feel a significant increase in effort to raise the deck.

 

[Hermio]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

I have had good luck with an under deck spray applied annually. I do not remember the name of the product.

 

[POGuy]

And what bad happens if leaving the crud in place? On my mowers it tends to eventually fall off by itself.

Loss of lift from blades.

 

[Jd1a]

My mower deck would clog, build up every time. Replaced the hi lift blades with regular blades. No more problems.

 

[JVR5333]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

Hey Bronco - I wish I could give you good news, but alas there is nothing quick and dirty (pun intended) here. I mow 30-acres of horse pastures - sometimes I get caught in rain with wet grass too. I mow the fescue very high - 5-1/2 to 6" in the grazing pastures, but even then grass and horse manure collects on the underside of the deck. I have to sharpen the 3 Skag blades about every 20hrs or less of mowing - I scrape underneath with a large putty knife every time I remove the blades - just part of the maintenance regime. Happy mowing my friend!

 

[cmjohn]

Sounds like someone has too much time on their hands

 

[JVR5333]

My mower deck would clog, build up every time. Replaced the hi lift blades with regular blades. No more problems.

I looked into hi-lift blades for my Skag 61" Turf-Tiger II zero turn machine, but after research and asking around - discovered that these blades greatly reduce the hp/rotation speed as they add a great deal of drag. Since I mow tall and thick pasture grass - I have to stick with the standard medium lift blades and keep them sharp. I rotate 3 different sets and have the "Yellow Hornet" blade sharpener - works awesome!

 

[dbritt]

I changed the oil in my Hustler today, and took a look around while under there. Clean as a whistle. It's never once had the deck cleaned
View attachment 3523963

I changed the oil in my Hustler today, and took a look around while under there. Clean as a whistle. It's never once had the deck cleaned
View attachment 3523963

So, in other words, you've never used it?

 

[Gord Baker]

Round off the corners of your scraper for better cleaning. You cannot do a proper coating on these decks without first Sandblasting. Just don't cut the wet grass. Use Weed and Feed if you can get it.

 

[ZiggyD]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

to prevent all the dandelion seed distribution

Dandelions have deep ground penetrating roots and their presence indicates compacted, low nutrient soil. They’re beneficial for breaking the soil and bringing up nutrients that other plants and grasses can then use. The best way to get rid of them is to treat the soil with nutrients and organic matter and over time (a few years) the grasses will overtake the dandelions.

Also, the seed bank in the ground is so well stocked that mowing before they go to seed makes little difference.

 

[Merck]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

I agree with everyone else. There is nothing you can put on that will stay and keep the grass from sticking. I mow 5 yards a week and usually just clean my mower deck every 3 - 4 mowings. Used to spray vegtable oil or WD40 on the under side of the deck. Did no good. Best to just buy a long handle stiff scrapper at the hardware or auto parts store and have at it.

 

[pmsmechanic]

I do some custom mowing. The best deck cleaner was a ditch that had been burnt in the fall. The willows were all about 3 to 4 feet high and dried right out. When the mower went over them it cut the dead branches all to pieces and after the mowing job the deck was clean. Almost like sandblasting. Unfortunately short dead willows are not always available.

This seems counter intuitive but if you mow the grass soaking wet, like after or during a rain the deck also comes out very clean. That opportunity doesn't always present it's self ether.

So it's back to mowing dry grass which fortunately is not hard to schedule in our dry climate. I rarely clean the decks as build up is seldom a problem.

 

[Rctex]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

My toro has water hose connection on top fabricated deck
Run mower few min
I guess the blades sling water hard enough to loosen it
Pull mower in shallow pool of water
Lower deck
Get after it
Make sure u have a Miller while having fun
With all jokes aside it will clean it good
Thanks

 

[John Renk]

Only thing I can think of is using hot water to break the grass glue, make sure you can use hot water in the pressure sprayer

 

[Paul McILwain]

I installed a garden hose clean out fitting to my deck and before each mow I connect a hose to a small pump with the suction hose in old oil. Turn on the deck at full speed and start the pump. I do it on the gravel with deck high so excess oil (not much you environmentalist) doesn’t get on the grass and helps keep the dust down. Still do a clean out in the fall but easy with vertical deck lift on my husq r322t AWD articulating mower

 

[dbritt]

No reason to get the tractor involved for such a simple task.View attachment 3534179

Some people just have too many toys! But, I'm jealous and would like to have one of those trucks, too. I was wondering how you got them up there. That 10 footer has to weigh a ton, literally. I've got a Bush Hog 3210 and I think weighs 2900 pounds. It's hard enough to raise the tongue with the jack, let alone putting it up on a shipping container.

 

[WinterDeere]

The best deck cleaner was a ditch that had been burnt in the fall.

I've mowed over countless snakes and baby bunnies, and one or two box turtles hiding in deep grass on the edge of our wetlands. It makes me wince every time, I truly hate it when it happens, but stopping distance at full speed is not sufficiently quick to avoid these things when they pop up just a few short feet in front of your deck in the line of travel.

Next time, I'm going to have to stop and see which gets the deck the cleanest, whirling around under there. Box turtles in particular make one heck of a racket.