42in SD deck with uneven cutting

[matt monte 132]

Im finally at ropes end regarding this issue. I have a 312-8 that was primarily used for snowblower use but decided to use her more often when a deck came up for sale local last year. I like it alot better than the RD 36in on my 308-8. The 42in has mulching blades that produce very little clumping of grass on lawn. Ive read up countless articles here as well as manuals on height adjustment. My chief complaint was at 1st deck height. was cutting at 2.5in....little short for my liking. Spent 2 days messing with it. got blade height to 3in by changing rear wheels, good enough i guess. now im noticing its not cutting 100% even, meaning i feel there is like a 2in strip of lawn not cut level, if that makes any sense. If i make a second pass i get it acceptable, but i shouldn't have to. Things ive done to attempt to remedy issue:

Set tire pressure

with deck on level surface in center setting, adjusted rear rod with a level on deck, got it level then back off one turn to pitch front a little as per manual.

Sharpened blades

changed deck belt

greased spindles,checked for wear,make sure bar with spring moved  with pressure to it

changed pto belt

 

from here im at a loss, i dont suspect bent deck, its not rusted either. Anything thing anyone feels i missed by all means, let me know

[daveoman1966 3,752]

Maybe deck is tilting....  you have it mounted correctly.  Look at these pics... 

[oliver2-44 9,787]

Look for any excessive wear on the attach-a-matic parts or the corresponding attachment area on the deck.

 

Also don't rule out a bent deck or bent area where a spindle attaches.  When when i refurbished the 42" SD deck for my sons 312-8 I had to do a bunch of heating straightening with a rosebud torch.  The PO had hit something and while there wasn't a big dent, the whole deck was bowed and the blades were not even due to the spindle area being bent.  1st try checking all blade tips to be the same height above a flat surface  check with the blades side to side and front to back.  You can shim a spindle with a washer if needed, but best to try and straighten.

[Rick3478 428]

So to clarify, you put 7" wheels on it to get up high enough?

 

It all sounds a bit odd.  You are letting it ride on the rear (gauge) wheels and using them to set height, right?

Not trying to use the lift handle to set height?  Lift mechanism is off-center and doesn't work for that.

 

It IS possible to put the PTO belt on wrong in such a way that the blades spin backward, and they don't cut worth a darn if you do that.

It IS also possible to put the blades on upside-down, which makes them cut poorly and shorter than expected.

 

There also can be airflow problems with some of the three blade decks.  The left blade only has to handle its own clippings, but the middle blade has to pass the clippings from the left blade plus its own, then airflow makes a sharper turn and the right blade has to handle the flow of all three.  So if the right blade can't handle all the flow, clippings or airflow may knock down grass in front of the blade gap area before the blades can cut it.  Your mulching blades could make this worse.  I've experimented a bit on a couple of my own decks, and what I've settled on is to make sure the right, final blade is the sharpest and has the best wings.  I also had two blades on the right spindle at one point tack welded at right angle to double the cutting and blowing surfaces, and that seemed to work okay but not a whole lot better than a single blade in great condition.

 

Don't know which if any of these apply, just putting it out there.

 

[oliver2-44 9,787]

Someone on here was using Gator mulching blades and sharpening the last 2 notched wings on the back edge of the blade.

[matt monte 132]

the rear deck wheels were  wore down to 5 1/2. I grabbed used but not worn wheels measuring 6in. from a parts deck that somewhat helped. I never thought to measure all 3 blades in search of a bent one, never thought mount hitch could be wrong or pto belt as well. I will check all above mentioned things as well as snap a few pics to post. Maybe u guys will pick up on something im overlooking.  To clarify the lawn cut doesn't look absolutely terrible but want this deck perfect. Im building a C-120 and want this deck for that. Want to put snowthrower back on the 312-8 and not do this deck swap every spring. I also have 308-8 & B80 with RD 36 decks, both run and cut out but afterwards i gotta break out the leaf blower dealing with pesky clumps. I never have that issue with the 42 SD. 

[lynnmor 7,322]

4 hours ago, matt monte said:

with deck on level surface in center setting, adjusted rear rod with a level on deck, got it level then back off one turn to pitch front a little as per manual.

 

Put that level away and measure from a FLAT floor to the blade tips, front and rear.  A tool like this one makes it easy:

 

[8ntruck 7,034]

Check the shaft that the 2 brackets that the gage wheels bolt to for a twist.  If those 2 brackets are not parallel when looking at them side to side, one side of the deck will ride a bit higher than the other.

[oliver2-44 9,787]

3 hours ago, matt monte said:

 I grabbed used but not worn wheels measuring 6in. 

Put some 7" new wheels on it to give you a little more heigtht flexibility

[matt monte 132]

[matt monte 132]

so i definitely got something going on here. All 3 blades while close, are not in alignment. Far right is the lowest on, coming in roughly 3 3/16, far left coming in at almost 3 1/2 and center one slightly in between those. I noticed a decent size dent center of deck. I had to have done that. I media blasted and painted this a few years back, i would have remembered a dent. no clue what i hit. Lawn isn't terrible. cut wise but i want looking like Yankee stadium. i just ordered a deck leveling gauge like lynnmor suggested. getiing under there with a measuring tape is ghetto, probably not very accurate. I never even knew that existed,lol.  Its looking more like a dent deck. i checked out that gage bar pretty good, seems level. once i get this tool i can more accurately determine what is the problem. ill most likely deal with this until the winter  

[8ntruck 7,034]

I think I saw somewhere that the front of the deck (blade maybe?) should be slightly closer to the ground than the rear - on the order of 1/4".

 

The Wheel Horse decks seem to be designed with a maximum cut height of around 3".  Taller cuts start messing with the lift and air flow, reducing the quality of cut.

 

I run my decks at maximum height.  I've tired mowing with the deck hanging from the lift mechanism and gage wheels off the ground - didn't like the results.

[matt monte 132]

i was under the impression grass should be 3 1/2.  im no expert, on anything actually looool. I'll adjust that nut in an attempt to push front of deck down but will wait until i get that buffy blade measuring tool!

[Lee1977 6,682]

That looks like tire tracks in tall grass to me.  Your lawn could be a lot softer then what we have down here. My lawn is as hard as concrete when dry and not much softer when wet.

I had a new deck that cut lower on one side but the height wheel bracket was either welded wrong or was bent. The dealer replaced the wheel bracket.

[matt monte 132]

your correct  about the wheels compacting the lawn, im guilty of watering a tad much, producing a soft environment but i have well water so i dont care, not getting a bill!  pic doesn't show the small roughly 2in patch thats roughly 1/4 in to 1/2 higher i guess in the middle. as i make the next pass i over compensate to get it but sometimes miss. Around me most decks that come up for sale look like they came off the deck of the Titanic,lol. As soon as i get that tool to measure ill mess with it a little more and report back

[Steve Janninck 171]

Matt,

Here are my thoughts, not saying I am correct, just thinking out loud.

 

So I am assuming all of the following are known goods.

No bent spindles.

No bent blades.

Deck is attached appropriately to the tractor.

 

From your picture of the lawn, it looks to me that all 3 blades are not the correct diameter, too short. This would leave a gap in between the rotors, not allowing strips of grass to be cut. The blade diameter is critical because blades are NOT timed and have very tight tolerance at the meeting points at the tips of the blades. 
I see you have the Gator Style Blades. Did you buy them or did the deck come with them?
I put down some notes to try to explain what I have experienced with the spindle and deck alignment. Let me know if something is confusing, they are just chicken scratches.

Also can you let us know the history of the deck? Just wanting to know if it ever had welding repairs or deck spindle cracks.

I think we can get your deck back to cutting that golf course flat beautiful look!

Steve

 

Note Aug 20, 2024 WH Deck Cutting issues.pdf

[lynnmor 7,322]

My 42" RD deck that is completely open doesn't give a great cut.  To get the highest cut I adjust so that the blade tips are the same front to rear.  My deck owners manual actually says to run the deck 1/8" higher in the front which is opposite from nearly all decks on the planet.  I don't think that engine speed has been mentioned yet, run the engine at maximum speed, 3600 RPM, check it with a tachometer, so you get maximum lift.  My 42" seems to turn too slow even at maximum, but I never checked or did the math.

[lynnmor 7,322]

My 42" deck has .03" washers above the blades and thicker ones below.     WASHER-FLAT [.760X1.25X.03]

[matt monte 132]

the deck i bought off market place a few years back, as is with those blades. I bought it for another project, my 308-8. Wasn't getting a great cut and was advised that the 8hp wasnt able to keep up with a 42in deck. I found a 36in deck for that which im aware isnt correct for it and produces a satisfactory cut, at best. The deck in question i media blasted and painted as well as greased spindles and replaced belt. I never thought or knew to check blade alignment or would thing the wrong blades were on it. I will take measurements hopefully today with that Amazon tool i just got. I suspect deck is bent or something is up with spindles. There is no rust weld patches but i did dent it somehow, honestly dont remember. Blades are not bent, i know that because i stuck a level on them last week when i had them off to sharpen. Anyone know what size blades it should have? Ill measure that as well today or tomorrow 

[matt monte 132]

[lynnmor 7,322]

4 hours ago, matt monte said:

With the rounded corners and the grinding on the bottom, I would call those blades spent.

[matt monte 132]

wanted to give an update regarding my mower deck. left blade is level, right side is off less than 1/16 of an inch. The center one is way off, by more than a 1/4 inch! It appears bent, the spindle or deck, not the blade. After the mowing season, when i swap deck out for snowthrower, Ill mess with deck and replace blades, as well as the deck with worn blades. Im assuming the box stores are not gonna have what i need. This measuring tool is an absolute necessity. Without it your really wasting time. Its like timing a small block chevy without a timing light. Sure u can get her running, but you need a light for accuracy. Th ank you for all who responded and took the time to offer your insight. 

[Steve Janninck 171]

Matt,

Good find using the new tool!

I agree the blade leveling and spindle diagnosis can come at the season change.

Keep us posted on your troubleshooting as you investigate the issue.

Steve