Center blade spin on ZD321

[Preachwright]

The center blade seems to free spin? I use an impact to change blades and have put new cupped washers on also in the past and never had this problem...
The shaft and splines are all solid but there is a cup shaped shield or guard that seems to let the center blade spin.
Any ideas? Yes I use an impact to tighten it all up good...

 

[85Hokie]

The center blade seems to free spin? I use an impact to change blades and have put new cupped washers on also in the past and never had this problem...
The shaft and splines are all solid but there is a cup shaped shield or guard that seems to let the center blade spin.
Any ideas? Yes I use an impact to tighten it all up good...

Can you send a picture of the "cup shaped shield" not sure what that is.

Are the washers bottoming out?

 

[whitetiger]

The center blade seems to free spin? I use an impact to change blades and have put new cupped washers on also in the past and never had this problem...
The shaft and splines are all solid but there is a cup shaped shield or guard that seems to let the center blade spin.
Any ideas? Yes I use an impact to tighten it all up good...

Make sure the spline on the hub, the piece the bolt goes thru, is engaged with the spline on the spindle shaft. If the splines are not engaged your blade will be loose with the bolt tight.
Loosen the bolt and see if you can turn the hub by hand, you should not be able to. If it turns, turn it to aline the splines, then tighten your bolt.
Also the Belleville washers both face with the cup up and set on the hub, under the blade.

The cup shaped shield should just sandwich between the blade and drive hub.
Torque on the bolt is 75ft lbs.

 

[Shelbygt660]

I have seen that the washers just become flat from over tightening them. As suggested also check the splines and the boss.

Sent from my SM-G930W8 using Tapatalk

 

[lugbolt]

The dust cup above the blade-or the one that's supposed to be there-is it there? If missing, the blade won't tighten up properly.

Washers, should be two of them, they are cup shaped. The center of the cup faces the spline boss, in other words downward.

Then the bolt. If the bolt is stretched, and they do stretch after being torqued a bunch of times, it will bottom out in the blind threads and never put enough pressure on the washers and spline boss to hold the blade tight.

Torque is 85 lb-ft, or that's what it's supposed to be. "Impact tight" can be anywhere from 30 lb-ft to 400. I've seen them loose and I've seen them broken off tight and everything in between. With good hardware and torqued properly, the blade will NOT spin. You'll kill the engine before the blade ever turns.