jerky zero turn mower

[chris1006]

This may not be correct place for this but since I can find limited info online about many different brands doing it I will start here. My father has a cub cadet z force 60 zero turn mower. He had surgery this week so I cut his grass for him using his mower. The thing bucks like a bronco. Not all the time but a lot of the time and mostly at slower speeds. I asked him if it always did this and his response was "for along time but if you run her wide open it doesn't do it". I have a toro zero turn myself so I know how they are supposed to operate and his aint right. Looking on line I see that other people have this problem but have yet to find any with a Yep, that fixed it answer. I have replaced the steering dampeners, Changed the trans/hydro oil and tightened what I could find that seemed loose to me. This may have made it a little better but still doing it pretty bad sometimes. I have yet to replace the belt as it looks pretty good. He said he had replaced all belts a few years ago. Just wondering if anyone on here has had similar issues. short of something being wrong with one of the hydro pumps not too much else to replace. It only has 320 hours on it.

 

[hawkeye08]

I think that is the one with a steering wheel? Perhaps the governor on the engine is lagging? It can't maintain and then adds throttle and then backs off and then adds?? Any change in engine speed or sound?

 

[junkjunkie]

Sounds like maybe the belt is slipping and you're not getting sufficient power to the hydrostats at all times. Is the belt or pulleys glazed over? Tensioner holding properly? Look at the crankshaft pulley on the engine and make sure the key isn't sheared also (a long shot, but worth a look).

Did you change the filters when you did the hydro oil (or did he have them changed after the initial break in period on the mower)?

 

[chris1006]

It does not have a steering wheel. I did change both filters when I changed the oil. Even used the expensive Cub Cadet transmission oil instead of the Rotella 15-40 the manual that came with the mower said to use. Dealer said it was synthetic and way better for the hydro drives. He never had it changed so it has gone 100 to 150 hours beyond what the manual suggested for changing. The belt is almost my last resort. He said he had changed all of them sometime back so was hesitant as it is like 50 -60 dollars. But I guess that's a cheap try if it fixes it verses 700ish for new drive motor or 5-6000ish for new mower. It does seem like the problem is coming from the right side drive motor. It is just weird how I see a lot of posts about mowers acting like this when googled but never anyone saying what it took to finally get it fixed. Makes me think its something going wrong with one of the drive motors. Either way, it certainly isn't a smooth enough ride to get on anytime soon(months) after a triple bypass.

 

[BukitCase]

I have the Cub RZT50, they are well-known for a slipping belt showing up as a "bad" right side drive motor due to belt routing - so far, mine has done this twice and both times a new belt fixed it. Yours may be different but it's worth a look as you said -

Also, my owner manual says to ALWAYS run at full throttle, and if you wanna go slower just don't push as hard on the levers - reason given is that each drive motor's cooling is provided by its own cooling fan mounted above the drive motor and run by the common drive belt - slow down the engine and you lessen the cooling, which can overheat the drive motors.

Again, I know mine is a different model, but it's probably worth a look... Steve

 

[chris1006]

Thanks for the info guys. I will be trying the belt this weekend and let yall know. We always do run the throttle full open.

 

[chris1006]

Well, the belt didn't help. Was a pain to replace to. I guess it has to be something wrong with the drive motor as I have replaced everything there is to replace now(other than that). The mower is still usable but after an hour on that thing you are certainly happy to get off it. If I come up with anything I will post it but thanks for the help.

 

[Jabonee]

Well, the belt didn't help. Was a pain to replace to. I guess it has to be something wrong with the drive motor as I have replaced everything there is to replace now(other than that). The mower is still usable but after an hour on that thing you are certainly happy to get off it. If I come up with anything I will post it but thanks for the help.

Trade it in for a SCAG. You will never need another mower.