To change or not to change....

BTBO

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Hi all----I just registered as a new member, and so I want to pose this question. While I am not a "Mr. Goodwrench", I am not totally clueless either. I recently purchased a Scag Liberty Z 48", and to this point am really happy with it. The question is whether or not it is advisable, after less that 10 hours on the machine, to drain the hydraulic oil and refill with a synthetic 20W50, such as Amsoil. The operators manual recommends this be done at 120 hours. Amsoil claims their product is specially formulated for zero turn mower hydrostatic transmissions vs 20W50 motor oil. Am I correct to feel that you can't change the oil too much or too soon? Also, I do plan to drain the KAWA engine at the early stage of 8 hours and fill with Mobil 1 20W50 along with using the Mobil 1 M1 102A filter. I contacted the tech dept at Mobil 1 and they said that this filter will work, though it has a slightly larger capacity.
 

cpurvis

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IMO, the 120 hour recommendation is probably a conservative estimate. The manufacturer has no reason to cut corners here because they're the ones who'll have to do the warranty work if that recommendation is too long. Will it hurt anything to change it early? I doubt it. Will it help? I doubt that, too.

The engine may or may not come from the factory with break-in oil. If it did, I'd leave it in for the recommended time, too. If not, change as early and often as you like.
 

bertsmobile1

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Most of the hydro tractors have no facility to change the oil .
The biggest danger is getting dust into the box
So it is not prudent to change the hydro oil too often
However an early change will not hurt one little bit
Just make sure everything is spotless and don't leave the filling apperture open for hours so airborne dust can drop in.
Also follow the air purge proceedure exactly and note that it is done at the lowest engine speed so you do not airate the oil.
 

BTBO

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IMO, the 120 hour recommendation is probably a conservative estimate. The manufacturer has no reason to cut corners here because they're the ones who'll have to do the warranty work if that recommendation is too long. Will it hurt anything to change it early? I doubt it. Will it help? I doubt that, too.

The engine may or may not come from the factory with break-in oil. If it did, I'd leave it in for the recommended time, too. If not, change as early and often as you like.

cpurvis---Thanks for your reply. I guess I was more concerned about the downside of changing the fluid too early. And after reading the claimed benefits by Amsoil, I felt that draining the factory 20W50 motor oil and refilling with their product "specially formulated for zero turn hydrostatic transmissions," that I could reap those benefits sooner than later.
 

BTBO

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Most of the hydro tractors have no facility to change the oil .
The biggest danger is getting dust into the box
So it is not prudent to change the hydro oil too often
However an early change will not hurt one little bit
Just make sure everything is spotless and don't leave the filling apperture open for hours so airborne dust can drop in.
Also follow the air purge proceedure exactly and note that it is done at the lowest engine speed so you do not airate the oil.

bertsmobile1---I appreciate your response. Since I have no shed or other enclosed structure to put my Scag in when not in use, I bought a pricey cover to shield it from the elements. When I do perform any maintenance, I'll be sure to use that cover to ward off any undesirable contaminates from entering places they shouldn't be.
 

Mad Mackie

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You will void the engine warranty if you use non OEM oil filters and non Kawasaki recommended engine oil.
Also, the use of synthetic engine oil during the break-in period will prolong the break-in and possibly not allow the rings to seat. Synthetic engine oil has a very strong detergent quality to it and will not allow the engine oil to 'coke up' the small leaks that occur in every piston engine.
As for the hydraulic system, here again using an oil that is not recommended by the transaxle manufacturer or Scag will void the warranty.
After the warranty period(s) expire, you are free to use what ever you want but at your own risk.
Synthetic engine oil is OK, but not the final answer. You still need to change oils and filters at the recommended intervals.
 

BTBO

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Mad Mackie....Thanks for you response. What you said all makes sense. As far as when to drain the engine oil, the Kawa owners manual says nothing about a break-in period, but to change the oil every 100 hours. There's no mention of recommended oil other than viscosity and API service, ditto for the filter. The Scag operators manual says to change it after 8 hours. Quite the time difference. I estimate for a full season of cutting I'll put 30-35 hrs on mower/engine. Based on that, it would take at least 3 years before an oil change. I may be wrong, but IMO that's too long to wait for the 1st drain/refill. I did ask the dealer about using synthetic engine oil, they said it was ok. I hear you about the warranty, and so will consider that when I do the maintenance and what to use.
 

bertsmobile1

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Scag are the people who you will be claiming any warranty service from so you do as Scag says.
I always recommend an engine oil change at the end of the season so you can forget about the hours.
Most would be lucky to do 100 hours a year so you will rarely run over time and during winter it will be there with nice fresh clean oil in the engine.
Transmission oil is a different matter because you are not dealing with the products of combustion
 

BTBO

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bertsmobile1---I just got off the phone with the tech dept @ Hydro-Gear. They say to change the hydraulic oil at 50 hrs since it is a "break-in" type oil. Afterwards to then use the 20W50 oil---conventional or synthetic along with the OEM Hydro-Gear filters, which in my case are HG52114.
 
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