2017 54inch ZRT - Loss of one side forward movement
 

So I was mowing the other day, and suddenly lost any forward or back movement of the left side. push arm forward or back little or no response. Turned it off , restarted and then had enough to get her back to the garage. Turned it off, looked at all the linkages and they looked fine, no leaks , nothing that I could see. Sat for 20 minutes or so , started back up and then mowed for another hour without issue except for a slightly lower response from forward and back pull on that left arm. Im baffled but thinking drive belt ( super hot that day)
That in itself looks like a bear to change. But any ideas or things I could look for or check
Thanks in advance

And the model of your ZRT is???????????????

I googled Cub ZRT,ASSUMING it is a cub cadet.
Turns out its a generic name, like SUV if for a common transportation vehicle.
Not being familiar with anything made in the last 40 years, I will sit on the sidelines.
But being 8 years old in todays throw away society, its prolly time for a new lawnmower.
or replacement of the hydro motor on that side if the belt is good.:bigthink:

ZRT = ?????
ZTR = Zero Turn Rider (generic for models FMZ, RZT, RZT-L, RZT-S, Series 360, Series Z, Tank L, Tank LZ, Tank S, Tank SZ, Ultima, Z Force L, and Z Force S)

sorry
Model # 17AICAXAO1O
2016
Serial
1L136H10020

CUB Cadet

here is tag

You have a separate hydro for each rear wheel and a single belt drives both of them simultaneously, so it doesn't seem likely that the belt is your problem.

What you are describing is the classic symptoms of hydro failure. They are repairable but that is neither cheap nor easy.
Some folks try changing the fluid but that rarely works for long, if at all.

thanks for the info
so a slipping belt or worn ( it is original , 612 hrs on the unit) would not cause this, how would I get a final diagnosis?

AND any thoughts on why it worked after I rested it for 20 minutes ?

and if I wanted to start with the belt , does the clutch HAVE to come off to replace , it looks like it will come off the tensioner and hydro units , but cant tell about over the clutch, looks like a wire I could disconnect but ???

Resting= cooling the hyd fluid which restores some viscosity from the hot temps you described.
No expert here, but I would make sure the fins on the hydro are clean.
You could try changing the hydro oil and it might buy you some time to decide if you want to go with a new hydro on that side or trade it.
it sounds like that hydro is on the the way out.
but If it were me, I do some more googling to see if they have known problems, maybe some one else here has experience with that model hydro.
obviously they don't build the quality like they did yesteryear, but I don't know the hour life expectancy of them. :bigthink:

You can go here and download your service manual,
second block down, left side, second line.
page 30 describes belt change procedure.
https://www.ccpartsnmore.com/cub-cadet-service-manuals

You can go here and download the hydro service manual,
https://www.hydro-gear.com/download/...27af1750701849

thanks seems like low hours to me, and they are non serviceable
so Ill keep searching to see of someone has
"been there done that" :bigthink:

thank you, that will help

Ironman -
so the manual shows a steering wheel model , but I assume that all the rest of the manual applies ? Mine has the push arms?
The belt R/R seems pretty strait forward in the manual

I suggested that manual because you said it is circa 2017, but you can look at earlier lever models from the same link to see if it is more appropriate.
If you look at page 34 for the S model, they do mention a worn belt could cause your problem.

Ironman and George are right. that hydro is well on its way to complete failure. they consist of a bi directional piston pump and hydro motor. the hydro oil gets hot and thins out, then it leaks past the erosion in the metal parts reducing its efficiency and finally cannot make motion. it cools quickly gains viscosity and will work marginally until it gets hot again. I have rebuilt a few of the unrebuildable units with limited success like 1 in 5! the problem is in many of the failed units -the part that is worn out is typically the housing - this is the pump discharge valve surface. basically the high pressure oil in the cylinder, headed to the motor, can escape to the reservoir or the next piston/cylinder at lower pressure instead of going toward forward motion. if you choose to open it up you you will see pitting in the ports from cavitation. The forward direction ports usually wears out first because it is used the most. I think I have always had the right side fail first as well. The higher end hydro units dont use the case for sealing or metering of the high pressure oil. because of this, they are completely rebuildable and more expensive. your best bet is gonna be to find a used same model mower or ZTR that used the same hydrotrans unit complete - one with a bad deck or motor and just swap that hydro out. then hope its not worse than what you had.

I've rebuilt a couple and the problem I have found is scoring on the mating surfaces of the Motor Block and Center Section. Yes, the oil gets hot and thins and the scoring lets the pressure escape.
All my rebuilds were successful, trouble is your looking at a couple hundred dollars in parts.

Ill try to source one as I try the belt first, but I agree with you folks, looks like it is destined to die fully

who do you all use for parts , if I can even find one?

and what is considered right , looking from the front or from the back

Left and right is established as the operator is sitting in the operator seat.:beerchug:

I am a bit late to this party and agree whole heartedly with the failure
of the pump theory. I am 99 percent sure of it. That said, in order to
satisfy the other one percent. I have worked on a couple these much
older then yours though.
The handles were adjustable in order to make the pressure put
on the pumps equal as the handles wore. Might take a look at how
your handles attach and how they interact with the pumps.
It's a long shot but it doesn't cost anything.

Ken

arms and travel look fine to me, but thanks for the input. The left pump is the one troubling, the right is fine.

Been trying to source a part number for the hydo unit left side

Cub calls it 918-05128B
Google that, also look at the label on the hydro case for the HydroGear model.

You REALLY should watch this video....
https://www.youtube.com/watch?v=t63MszuDLfE

wow that is over my head for sure, but I did find the issue
the top of the left drive - where the cooling fan "axle" goes into housing - and that is where it is leaking, looks like a rebuild is possible according to video , but ...
so looking now for a left tranny

they are quite pricey I see, perhaps I can find a good used one, but does anyone know an individual or business that can rebuild the one I have ?

sourced a used one , and noticed this - is this a fill port for transmission oil ?

my old one, is leaking fluid , and if this is a fill port perhaps topping it off would get me through the summer. work on replacing when its not 95 degrees Thoughts?

I gave you the link to the service manual in post #11.

Just spit balling here but if you are trying to just get through the
summer. How about a fluid change to a heavier weight oil?


Ken

good ideA , think it callS for 20-50 , so perhaps just plain 50W