I just read an earlier informative post on changing the hydraulic oil on the Hydro-Gear ZT 3100 trans-axle system. My mower (Gravely) has the ZT 3200 with essentially the same instructions for the procedure in the Gravely Owner's manual. My question concerns the oil that is used. Is there any reason for not using or benefit from using a synthetic or synthetic blend ? The manual just says 20W-50 engine oil - but, doesn't distinguish. The kids (18 to 21 year olds) at the local service facility can't give me a definitive answer. Incidentally, the earlier post also mentioned how the service locations try to gouge the consumer. The service facility near me wanted $59 each for 18" OEM blades that can be bought for $18 each online (identical Ariens OEM blades) - so much for dealing with those people anymore.
Hydraulic oil type
- Thread starter Marlo235
- Start date
Well here is my spin on synthetic oils. They are manufactured to be an exact molecular structure to maintain consistent lubrication and prevent mechanical failure. Cost more but can run longer without changing. Now the way I figure it is there is a reason they guarantee the product to withstand the temperature and prevention of thermal breakdown. Dino oil is also good and you have followers that swear by it. Some because the synthetic cost more. Now, I found my hydrostatic transmission in my Tractor was quieter, had increased power and smoother operation with synthetic. Changed it after 10 years and it was as clean as the new that was replaced. The suction screen was clean. The engine oil is changed annually. Oh I was blowing out the FEL hydraulic lift quick connect on my FEL. 6 of them. When I changed to synthetic at 50 hours haven't replaced since. I am a supporter. I by AMSOIL. I figure they guarantee their product and that's all they make. There are some te h guys on other forums that can really give you more specific facts. Www.it TractorByNet.com, GreenTractorTalk.com, do a search for Tractor forums.
Bottom line, research the pros and cons.
Bottom line, research the pros and cons.
djdicetn
Lawn Addict
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If this is your first hydraulic oil change most likely your Gravely is still new enough to be under warranty. IMHO, I would as the service manager at your dealer before going with synthetic in the HydroGear ZT-3200's. You wouldn't want to do something that may void your warranty should you have tranny problems while your ZTR is under warranty. Just my $.02 worth:0)
Just noticed that one hydro fluid reservoir was slightly low. I purchased Valvoline 20W-50 synthetic with an API rating of SN, although the Gravely manual recommends SL. SN is the latest API designation and covers earlier API versions including SL. SN just meets the latest and highest standard for oxidation, wear, etc. In my amateur opinion, I would never go less than the SL rating but going with a later and improved version, that would include synthetic, should not be a problem for either lawn mowers or auto engines.
I recently changed the oil in my hydros but before I did I called Hydro-gear and asked what they recommend.
The man I spoke to said all Hydro gears ship out with MOBIL conventional oil.
It was alright to use synthetic but not necessary.
So then I called Snapper Pro. They suggested synthetic but said it was not necessary.
So what did I use? Valvoline Full Synthetic 20w50 just because I can!
The man I spoke to said all Hydro gears ship out with MOBIL conventional oil.
It was alright to use synthetic but not necessary.
So then I called Snapper Pro. They suggested synthetic but said it was not necessary.
So what did I use? Valvoline Full Synthetic 20w50 just because I can!
graydog
Active Member
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- Mar 16, 2012
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Thanks, ddbtdd. I was wondering about synthetic for my hydrostatic drive. My Great Dane Chariot book says to use 15W-50 all synthetic oil.