ZD21F Deck PTO Shaft Hard to rotate.

OrangeGreg1986

New member

Equipment
ZD21F
Oct 18, 2016
1
0
0
Attica, Indiana, US
Hi everyone.
I have a ZD21 with 2,887 hrs on it. This Kubota runs 20hrs a week. this mower been greased every time before it leaves the barn, and every month the gear box on the deck gets a oil change. and the trans oil and filter gets changed every 3 months.
Now this mower has had the transmission upgrade from left drive pump fail. and the tank mod to void anymore drive pump failers. that was at 800hrs.

The problem im having is the deck is vibrating really bad. so i changed
Blades, still vibrating(shaking). Removed belt. Belt was good. changed 50hrs ago. now when i removed belt i checked the deck bearings. only found one bad bearing on the top left. replaced bearing, hoping that was my problem, i started the mower agian. and still vibration as soon as i engage the pto. so i started removing the deck. and noticed that the blades were hard to spin. so i finished removing the deck and the deck moves free and smooth and the u joints on the pto shaft are good , not locked up or loose. now i put half of the pto shaft back on the trans and notice it was kinda tough to spin.
so i found out that the pto clutch assembly has a brake in it as well to slow the blades down faster. im starting to think this maybe my problem. like the brake in the clutch is locked up. so i guess what im trying to find out is the shaft suppose to have a lots of drag? (not running)
 

rjcorazza

Member

Equipment
L4060 HSTC Loader, ZD326, ZD1211
Mar 9, 2016
778
22
18
Hyattstown, MD
I never really gave it any thought, but since my ZD326 was new when manually rotating the pto shaft for grease zerk access I am turning the engine. This is with the machine off and mower deck disengaged. Doesn't sound like it should be this way, but since day one and 1400h later this is how my mower is.
On edit... Now that I think about it I am not certain I am rotating the engine except for the rear most u joint. I will check later. In any case, there has always been a lot of resistance when manually rotating the spindles or drive shaft.
 
Last edited:

1970cs

New member
Apr 26, 2016
1,124
3
0
Grand Ledge
What does the PTO output shaft do when the engine is on, but the PTO lever disengaged? I mean don't physically turn it but watch it.

Pat
 

rjcorazza

Member

Equipment
L4060 HSTC Loader, ZD326, ZD1211
Mar 9, 2016
778
22
18
Hyattstown, MD
I checked my deck today, and it is not turning the engine like I said in my previous reply. With the machine off and mower deck disengaged, there is (and has always been) significant resistance when turning the blades. I can just barely rotate the deck by turning an outside spindle pulley by hand.
 

1970cs

New member
Apr 26, 2016
1,124
3
0
Grand Ledge
I was following your last sentence in your original post! You still should report your findings on that.

Remove the deck take off PTO shaft at gear box and the remove the belt.

Turn each blade by hand, check for noises or hard to turn. Also turn each blade tip to tip to check for a bent arbor or blade ( I read that you replaced them) check the idler pulley for drag. I would take the PTO shaft and telescope it out to where it runs most of the time and check for wear or slop in the splines

Do you have another implement to run?

Pat