Deck Blades Way Off

[Texas Todd 1,025]

Bought a 520xi with a 52" Side Discharge Deck #78370. Got the belt gremlins figured out I think. I replaced all of the spindle bearings as the left one was shot and sounded like a B-52 in flight.  It's a very strong mower, but the scalp mark going down the middle of each pass, isn't good. The center blade is cutting significantly lower than the outside blades. I measured the right and center on concrete and the middle blade, when pointed straight forward, is about 5/8" lower than the right side blade, when it is pointed forward. When I turn the blade tips to meet (side to side bias), they are pretty close to being the same height, maybe off a 1/16" to 1/8".

 

I removed the anti-scalp rollers in the front when measuring as well. I didn't mow enough with it before I changed out the bearings to really get a feel for the cut, but I would think it would have jumped out at me....

 

Any suggestions? I am at a loss.

Edited August 25, 2017 by Texas Todd

[doc724 925]

A couple of things come to mind.  Simple ones first. 

1.  Did you level the deck the way the manual tells you to do it? 

2.  Do both ends of the center blade have this 5/8 inch lower behavior?

3.  With the deck removed from the tractor and the top of the deck shell level, does the center pulley tilt forward?  You have to eyeball it.

4.  What method are you using to measure the blade height to ground.  I have found that you cannot measuring instrument to get an accurate measurement.  I have to use gage blocks on mine.

[pfrederi 17,697]

the center blade is 5/8 inch lower in front is it about the same amount high at the rear??? If so the deck shell may be bent at the center pulley

[Texas Todd 1,025]

All good suggestions. I will wrestle the beast out this afternoon and analyze.  I will have to find a manual regarding leveling. Haven't been able to find one of that model.

 

I was able to measure the right and center blades with a tape, but that wont work for the left blade. At 5/8" difference, its pretty easy to eyeball a significant difference. I will check the difference on the rear pointed bias as well. Thanks guys. Will report what I find.

[doc724 925]

Todd, make your self some gauge blocks out of a  2x3 or 2x4.  Make one at 2 1/4 high and then make successive one 1/8 inch taller up to 2 7/8.  Make sure you label them-it will be easy to mix them up if you don't.  With the deck on your tractor, set it about mid height and then slide the gauge blocks between the underside of the blade and the concrete floor.  You can check all blades in north-south, east-west positioning and you will be accurate within 1/8 inch.  As pfredrei said, the center pulley may be bent forward (or the shell is cracked).  Hard to do on an xi deck but very common on classic tractor decks (the xi deck has a tension indicator on the mule drive whereas the classic tractors you set tension by feel and too many owners have cranked them too tight)

By the way, if you go to Toro site, under homeowner, manuals, you can download the manual for free

[Texas Todd 1,025]

Finally got around to it this morning. Took the deck off and didn't see any obvious cracks and cant see that its bent, but apparently it must be. It still spins fine

I guess until I stumble on another deck this will just have to be a shredder for tall grass, not lawn mowing....

[wrightorchid 261]

I have the same issue, but I know I hit a hefty oak root.  The center scalps pretty bad.  If you have the deck off, you can put a long level across the shell, and see the difference between the blades and the front of the shell, when the blades are all to the front, like III, It sounds like something similar may have happened in the past.  I'd love to have another good deck, but in Florida they are hard to find.  This winter I'll try to remove the center spindle, and try to heat and hammer it back in place.  

[shallowwatersailor 3,213]

Just like Doc said, you need to measure the blade height. Find the Owners manual here in the Manuals section. You may have an issue with the deck being attached to the tractor as well. Once again I offer the suggestion on RS of getting one of these tools to measure the blade height made by Sten, etc. I found mine at a JD dealer. It makes life much simpler.

 

When you changed the spindle bearings, did you seat them completely in the spindle housing? Did you install the spacer on the shaft between the bearings? There should not be any movement up or down on the shaft.

 

 

[Texas Todd 1,025]

Yes. I removed the center spindle to make sure, all the parts are there and no movement up and down. 

 

I suspect I must have over tightened the PTO belt before realizing the gauges were present. I was trying to figure out a way to try to bend it back, but figured I would probably just make it worse. 

 

Thats a neat gadget. I will have to get one.

Edited August 28, 2017 by Texas Todd