ZD21 blade not cutting under load

[TexasTorg]

Greetings, new to the Forum.

I recently replaced blades and belt on ZD21 zero turn. Everything seemed to be working great but my right side blade (near grass shoot) is not cutting when i get in any kind of grass. It spins when mower is engaged, but only cuts if there's almost no resistance. When i get into any moderately tall grass, the other blades cut just fine but the right one just knocks the grass down and cuts only a little bit. I've rechecked and the blades are correct and the belt is too.

Could it be something with the spindle on that right side blade? I need to recheck to make sure it's tightened similar to the others too.

thanks! Any suggestions are appreciated.
brian

 

[85Hokie]

I would double check the "tightness" of that spindle/blade bolt - I had one a couple of years ago do something very similar.

Is there only ONE belt or several? If multiple belt - check that tension of that spindle.

 

[North Idaho Wolfman]

I'm seeing two options:
Most common is that the two washers (yellow) are damaged missing or improperly installed.
Second would be the key (blue) is sheared and and the spindle is slipping inside the pulley.

 

[TexasTorg]

I'm seeing two options:
Most common is that the two washers (yellow) are damaged missing or improperly installed.
Second would be the key (blue) is sheared and and the spindle is slipping inside the pulley.

View attachment 143360

Those are good suggestions, i'll take a look at it tomorrow!

 

[TexasTorg]

I would double check the "tightness" of that spindle/blade bolt - I had one a couple of years ago do something very similar.

Is there only ONE belt or several? If multiple belt - check that tension of that spindle.

One belt. I'll check the tightness on the spindle/blade. thanks!

 

[mikester]

When my ZTR isn't mowing properly at speed I know its time to scrape and clean the deck. Works like magic.

 

[Workerbee]

On my ZD thats happened occasionally, and its always been the cup washers. Perhaps you didn’t tighten the bolts enough the last time you changed blades? Or if they’re tight, its time for new washers.

 

[lugbolt]

yup damaged, misplaced, or missing "spring corns" or loose bolt are usually what I see on that style.

spring corns...for a good while kubota called blade washers "spring corn". Jinglish I guess. Dunno.

kind of an overcomplicated way to hold mower blades on but I guess their enginerds have it all figured out. Problem is, when an owner goes to change or sharpen blades, all those parts scatter and with it's overcomplexity, makes it a little harder to figure out how they go. I've seen them missing, washers on top, one on top one on bottom, missing "boss spline", etc. They will all go on in different ways but there is only one correct way. Review the parts diagrams for your equipment (specifically your mower deck, as you will not find blades and hardware in "ZD21", but you will find it in RCK60P-21Z).

good luck.

Oh by the way, 30mm socket....

 

[CGMKCM]

I have had this happen on my ZD 323 when using non OEM blades.
For example, Oregon G-5 blades are thinner then the OEM blades and the clamping force of the cupped washers is reduced. The bolt will torque to the correct value. The fix is make sure blades are the same thickness as OEM blades.