I have an 04 ZD21 that I purchased from an estate, it is extremely clean and has been functioning flawlessly until yesterday when the right wheel stopped turning forward or reverse. The right drive motor was slightly slower than the left wheel when I got it but hardly noticeable, there was no warning/noises/issues when it failed, I was halfway through mowing, I finished a stripe and went to spin and the stick just went dead. The right control makes no noise whatsoever when I move it, and there is zero pressure when I move it forward. I've read several posts on these machines potential hydro issues, before I go crazy ordering parts I am trying to figure out what to do to correctly diagnose failure. I got a screaming deal on this thing (at least I think I did) from an estate sale, I knew the original owner and I know the mower was only ever used to mow his private three hole golf course. I can't afford to send this thing to the Kubota dealer, they already told me it would be 700+ to even tear it down far enough to diagnose the issue, I am a solid auto mechanic and have a shop full of tools.
ZD21 Right Drive Motor Issue
- Thread starter MCSeattle
- Start date
While there is an issue with drive motor failures, it sounds more like a linkage issue to me. Pop the seat up and move the lever and watch the linkage. Make sure it is all intact. Compare it to the working side. FatJay over on the TBN site documented his repair of the drive system on a ZD21 a few years back. Hopefully your repair will be less involved. My ZD21 has almost 1600 hours and is still going strong.
Thats the odd part, the linkage all seems perfectly fine, the movement is the same on right and left motor controls. In my past experience with hydro failures I would at least hear a "whine" when the controls are moved, there is absolutely no sound and no resistance now.
I don’t know this machine, get your salt shaker ready.
Where the linkage attaches to the pump, is it moving the rod into the pump?
Where the linkage attaches to the pump, is it moving the rod into the pump?
Yes it seems to be moving the rod into the pump. I’m looking for some troubleshooting steps to determine if I need to pull the motor for that right wheel or not, I haven’t found anything yet
Had to run out and take a look at mine. There is a "bell crank" that attaches to the shaft that runs into the motor case that works the swash plate. It has a roll pin that attaches it to the shaft. Might that be sheared?
That would be something you couldn't see wrong with out driving the pin out. It would be easy to check.
Might be able to check it just by prying up on the bell crank.
That would be something you couldn't see wrong with out driving the pin out. It would be easy to check.
Might be able to check it just by prying up on the bell crank.
DUSTY THAT WAS IT !!!! The pin snapped INSIDE the hole, leaving it visually looking like the pin was still all the way through, I grabbed a new roll pin out of my toolbox and slowly tapped the old one out while putting a new one in, the old one came out in THREE pieces ....
Just tested it out, moves PERFECT and ... as an added bonus, the right side is no longer slower than the left! My theory is that one of the cracks in the pin happened some time ago and the second one gave way due to the force.
THANK YOU ALL FOR THE HELPFUL POSTS !!!
Mike
I don't want to be the bearer of bad news or a negative Nancy but just got my ZD21 out of the shop last Friday, I had similar problems the dealer advised he has done several of these and that Kubota has a drop in program for these where they replace the entire assembly and it adds an additional tank to hold more oil . I guess Kubota designed the tranny so as it did not hold enough oil for hilly terrain. Funny thing is I don't have what I would call hilly terrain. But then again it did last me about 18 years, but the $4,500 hurt........