I am 69 years old and never had a ztr before. Tractor with finish mower has been my life. Well, my neighbor just moved and sold me his ZD21 (cheap). I am a motorhead so I got it as a project for my work shop. I now love the damn thing. First thing is change all fluids, my rule. Engine oil done but how about the rear two drives? Two dip sticks , one on each side? What type of oil are people running in rear drive. Transmission takes thin Kubota oil since he gave me 2 1/2 gallons of that. Any help appreciated. Anything else I need to know? I just cut 4 acres and smoked my Tractor time by a bunch.
New member with ZD21
- Thread starter yellowjacket
- Start date
I had a ZD21 from 2003 when I bought it new until 2011 when I traded for a ZD326. The 21 was a great machine and I had no issues in 500 hours of operation. Definitely use Super UDT+ in it. Also there is a suction screen on the bottom you need to pull and clean. It only uses one spin on pressure side filter. Check your mower gearbox as well. They don’t hold much. I changed my gearbox oil and used full synthetic gear oil
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Agree about the gear box maintenance! Frequently neglected. I run 75w140 synthetic in all of my gear boxes, and replace the fluid religiously.
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Thanks guys, I will most definitely get a service manual for the Zd21. I love those books and have one for just about everything I ever owned. So, The rear drives are independent and have their own dip stick. Trans and rear take same oil. Is the drain plug for the rear that large hex hear facing a little forward from bottom center? Thanks.
Don't forget the oil strainer and HST filter, covered in manual here
http://www.kubotabooks.com/AutoInde...11R, ZD1211L, ZD1211RL_9Y111-13443[1] WSM.pdf
http://www.kubotabooks.com/AutoInde...11R, ZD1211L, ZD1211RL_9Y111-13443[1] WSM.pdf
Daren Todd
Well-known member
Lifetime Member
Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
Make sure and check the manual before using super UDT for the transaxles!!!!!
That was my assumption when I bought my z121s zero turn and was talking to the salesman. He pointed out that the transaxles do not use super UDT.
If I remember right, they take 20w50. But don't hold me to that. It was several months ago when I serviced it front to back. And bought the oil based off the owners manual.
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That was my assumption when I bought my z121s zero turn and was talking to the salesman. He pointed out that the transaxles do not use super UDT.
If I remember right, they take 20w50. But don't hold me to that. It was several months ago when I serviced it front to back. And bought the oil based off the owners manual.
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When I pull the dip stick from both rear drives, the oil on the stick seems thin and same as transmission. Not thicker gear oil or even 20-50
Wow.
Super UDT in the HST, and BOTH brake cases (the two cases that are behind the wheel hubs)-they all work on the same oil but you've got to drain the brake cases independently of the HST housing. Super UDT ONLY, and you're going to want to change it pretty often especially if you live in a warmer climate. Basically anywhere that's south of about South Dakota. The HSTs weren't known to be "strong"....although the ZD25 and ZD28 were more notorious for issues than the 21 was. There is a suction filter/screen on the HST as well and it needs to be cleaned. And replace the spin on filter.
Mower deck gear box is 80w90 or super UDT, I prefer 80w90 because it absolutely stinks when it leaks out....and you notice it quicker. Actually I can't remember the last time I put super UDT in a mower deck gearbox. 75w90, 80w90, 85w140, it all does the same thing-and I like non synthetic because of the stink that it gives off when it's leaking. That box is hard to get to, I find it easier to remove the mower deck from the tractor and then service it while the deck's out. Kubota did not put an access panel on the older ZD series. The ZD300's and newer have a panel in the floor that can be lifted to gain access to the deck gearbox.
Z121 uses hydrogear HST's, and they all use 20w50 but that's a different subject IMO for a different post.
Super UDT in the HST, and BOTH brake cases (the two cases that are behind the wheel hubs)-they all work on the same oil but you've got to drain the brake cases independently of the HST housing. Super UDT ONLY, and you're going to want to change it pretty often especially if you live in a warmer climate. Basically anywhere that's south of about South Dakota. The HSTs weren't known to be "strong"....although the ZD25 and ZD28 were more notorious for issues than the 21 was. There is a suction filter/screen on the HST as well and it needs to be cleaned. And replace the spin on filter.
Mower deck gear box is 80w90 or super UDT, I prefer 80w90 because it absolutely stinks when it leaks out....and you notice it quicker. Actually I can't remember the last time I put super UDT in a mower deck gearbox. 75w90, 80w90, 85w140, it all does the same thing-and I like non synthetic because of the stink that it gives off when it's leaking. That box is hard to get to, I find it easier to remove the mower deck from the tractor and then service it while the deck's out. Kubota did not put an access panel on the older ZD series. The ZD300's and newer have a panel in the floor that can be lifted to gain access to the deck gearbox.
Z121 uses hydrogear HST's, and they all use 20w50 but that's a different subject IMO for a different post.
Thanks to all, I am learning more and more each day about this now project mower. The only other thing i need to address is starting. When the starter is engaged, the motor spins over more than my other diesel stuff, 2 trucks, generator, JD Tractor. All fuel filters are new. Any ideas? it does start and runs great but just takes longer to start. Moving throttle up a little seems to help. Throttle pulled all the way back, not so good.
A little trick in those is to take a sawzall and cut a notch back where the park brake pedal comes through I think. Then with a few bolts the entire foot rest area will lift off for easy access. The notch will be under the mat so it won’t show. Good for belt changes, gearbox or spindle work. I never needed to do it but did the notch anyway
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That will be one of my winter projects. I already measured and will cut me an access door. It will have a s/s piano hinge and look just like the new ones have. I will weld tabs underneath and from the top you will only see a line in the rubber mat. I love this kind of stuff.
Well I got so much good help with my new mower, how about this one. My fuel gauge does not work. I would like some feedback before I tear into it. I cant reach under the thing very easily but seems all wires are hooked up.
Download the ZD21 work shop manual (free): HERE. The previous link in post 7 was for the ZD1211 manual not the ZD21. Look on pdf page 216, it has the wiring and resistance value checks for the fuel level sensor.
On my '06 ZD-21, the brake pedal comes off by removing the two 12 mm bolts attaching it which are right below the footrest panel.