How to fix uneven cut

[yooperdave]

I brought my 6 year old 54" Toro ZTR mower in late last Fall to get the blades sharpened, tune-up and a wash. I was moving 75 miles away and wanted to get the mower as maintained as possible before relocating. Starting the Spring mowing season, it was more than apparent that the mower was not cutting evenly. The grass was growing like crazy as we received more than 8" of rain beyond the average for April. I cut the lawn to at least get the grass under control. What suggestions do you have to level out the cut? TIA

Yooper Dave

 

[CloverKnollFarms]

Well, the last time I "fixed" a mower for this... The owner had one rear tire inflated to 40psi!!!! The other was the correct 8psi. Once I deflated the tire, it was fine.

It could also be an issue in the linkage that the deck is suspended from.

But, if it happened all of a sudden, while not in use, I'd be looking for a flat or over-inflated tire

 

[Eagle1]

Or a loose blade bolt.

 

[Runner]

It helps to have a good blade height gauge.

 

[CH4Ohio]

I'd measure the DECK height side-to-side. And also measure the BLADE-to-GROUND height side-to-side. If your deck is bent or tweaked, this should show it.

As mentioned above, first be sure all tires are at the same pressure.

Are any blades bent?

If all of that seems OK, then you'll look at the linkages that the deck hangs from. I'd be surprised if TORO doesn't have a pretty simple leveling system -- need to check the manual online. I have a 60" Cub Cadet where you adjust hangers on a threaded-rod -- sorta like a turnbuckle assembly. Your hardware will determine how to proceed.

Also wouldn't be surprised if one side is more adjustable than the other. Check it out. Often designed with more flexible / adjustable hangers on one side.

 

[sandman2234]

It helps to have a good blade height gauge.
View attachment 5708865

I can't even figure out how to use that guage!
How about just a tape measure?
David from jax

 

[KennyG]

All good suggestions. The JD gauge is cheap and easy to use (Except for David? ). That pattern is so bad, I would pull the blades and make sure one of them isn't loose or badly bent. If none of this helps,you may have to consider a bent spindle, although that is almost impossible.

 

[CH4Ohio]

I can't even figure out how to use that guage!
How about just a tape measure?
David from jax

The gauge tool looks really handy to me! Problem is, I'd never be able to find it when needed.

 

[sandman2234]

The gauge tool looks really handy to me! Problem is, I'd never be able to find it when needed.

I can't find a tape measure when I need one!
David from jax

 

[sandman2234]

I can't find a tape measure when I need one!
David from jax

Neighbor asked if he could use my TIG welder to build a T-top for his boat.
First day, we can't find a tape measure, so he walks down to his house and gets one.
He left it at my house at end of day.
Day two, we can't find a tape measure, so he walks down to his and gets one.
He left it at my house at end of day.
Day three, we can't find a tape measure, so he walks down to his house and gets one.
He left it at my house at end of day.
Day four, we can't find a tape measure, so he walks down to his house and gets one.
He left it at my house at end of day.
Day five, we started tripping over tape measures like crazy!
The next day he brought me a neon green tape measure because he figured it could be seen anywhere!
I probably only had a dozen or so tape measures around here on day one!
David from jax

 

[2manyrocks]

It's possible that the deck is mounted unevenly to the mower. Are the hangar bolts bound up or is a stick keeping them from holding the deck evenly?

Also possible that one of the blades is bent or the deck itself could be bent.

I bent my deck last year. Although there are a bunch of videos on YT, the one that helped me was the one by Individualized Repair. It helped to gradually beat it back to shape almost like an auto body repair instead of trying to beat it back straight with a few heavy whacks.

Patience also helpful. I had to measure and re-measure several times.

 

[bigtiller]

Did you put the blades on upside-down?

 

[dadohead]

I can't even figure out how to use that guage!

I used to design mower decks. Before cut quality testing, EVERY deck was leveled. Those gages are wonderful.

1. Check tire pressure
2. Gage wheels should be raised out of the way.
3. Next adjust side-to-side level on flat surface. Set HOC on machine to 3". Turn LH blade to 9 o'clock position. Since you want 1/4" of total rake, adjust height so LH blade is 3 1/8" @ 9:00.
4. Turn RH blade to 3 o'clock position and adjust to 3 1/8" height. If badly out of adjustment, it may take several iterations to get LH/RH blades to 3 1/8" at full width.
5. Adjust rake last: work through discharge chute. Rotate outer blade to 12 o'clock position and adjust so blade front is 3" (blade rear should be very close to 3 1/4").
6. Adjust gage wheels to a finger thickness clearance at the height you're cutting to.

Note: you never need to measure the center blade on a 3 spindle deck... just the outer ones. Also note the center blade will cut just a hair under 3" (due to rake) when the outer ones are at 3" HOC.

The deck will be dead level and calibrated to the HOC control on your machine. I check mine every Spring and it usually needs little adjustment. Hope this helps!

 

[oldnslo]

Is one blade on upside down? Also looks like one blade is leaving a stripe vs deck being tilted.

If transported look to see if some in lift linkage on one side bounced out of position and is hanging up or broken.

 

[AntiqueIron]

I brought my 6 year old 54" Toro ZTR mower in late last Fall to get the blades sharpened, tune-up and a wash. I was moving 75 miles away and wanted to get the mower as maintained as possible before relocating. Starting the Spring mowing season, it was more than apparent that the mower was not cutting evenly. The grass was growing like crazy as we received more than 8" of rain beyond the average for April. I cut the lawn to at least get the grass under control. What suggestions do you have to level out the cut? TIA

Yooper Dave

Lawn mower mechanic here.

First three things to check: blades for straightness (lift machine, spin each one around, check tips of each blade against each tip of the mating blade), lift trunnions, (cast lift blocks often wear unevenly), and deck level (caused in part by tire pressure.


I like to level decks at 6 points- with the blades facing parallel to the machine, you should record 1/8-1/4” lower in the front than the rear. I check both outer blades at the front tip and both at the rear.

First though check your side-to-side: with the tires at a proper pressure, set the blades perpendicular to the machine, and measure for level.

1/4 inch is within spec, I aim for 1/8 or less difference.

Hope this helps.


Oh, and unless you’re brush hogging, it’s rare to bend a deck shell, especially a fabricated deck, much less that badly.

Same for spindles.

 

[AntiqueIron]

I can't even figure out how to use that guage!
How about just a tape measure?
David from jax

You set the position of the blade for either rake or level, then guide the arm into the cutting edge of the blade at the tip.

Rake is set at the forward and backward edges of the deck with the blades parallel to the frame.

Level is set with blades perpendicular, but you can usually get away with setting it with the blades parallel as well.

 

[CloverKnollFarms]

I got money on tire pressure

 

[RayIN]

I can't even figure out how to use that guage!
How about just a tape measure?
David from jax

Yep, level concrete floor and ruler; but after all tires are inflated to owners manual specs.
For those doubters, yes a 5 psi or over inflation difference in rear tires can cause that "ledging" look. They can appear the same height, until you plop your arse in the seat.