Hydrogear Transmission spec 20w50 is 15w50 ok?

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My ZTR mower has two Hydrogear 3100 Transmissions. The owners manual calls for 20W50, API SL.
Can I use 15W50? I would like to use Mobile 1 they do not offer 20W50 in standard oil, only in VTwin Motorcycle oil and its API SH.
 
Anything between a 15w40 and 20w50 is what Hydrogear specs for the ZT series 2800's, 3100's and beyond. I'd use that M1 15w50 without a worry.

In the event you haven't, the ZT series spin-on filters can be had on Amazon.com or eBay for good prices.

Joel
 
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Look at Amsoil site, Study of motorcycle oils.

M1 V Twin is one of the most shear resistant oils. It is on the top of the graph for 50 group 2.

It would be difficult to find a better oil.
 
I have 3 hydrogear units and have had good service. The oldest one is 10 years old and has over 600 hours on it. I have tried several different oils including Mobile 15w50. I called Hydrogear and they simply recommend regular 20w50. My machines work the smoothest and quietest with walmart 20w50.
 
Originally Posted By: sweezy722
My machines work the smoothest and quietest with walmart 20w50.


I don't doubt that.

People tend to go a bit over the top with more expensive oils due to the difficulty in changing the oil in most of these drives.

The original poster's ZT-3100's are over $1000/ea and there's two of them on the machine. Good news is they are relatively easy to change oil on and each have their own little spin-on filter.

ZT-3100.jpg


Joel
 
Originally Posted By: sweezy722
I have 3 hydrogear units and have had good service. The oldest one is 10 years old and has over 600 hours on it. I have tried several different oils including Mobile 15w50. I called Hydrogear and they simply recommend regular 20w50. My machines work the smoothest and quietest with walmart 20w50.




I wonder if they say that because you would have to spend money on a new unit if it fails? Or if there is truly no advantage to using Synthetic oil in them?
 
I put Mobil 1 15x50 in my Tuff Torq.I don't know if they're is much difference between the TT and your Hydrogear but my 1998 john deere LX still runs like new! Thanks, Gman
 
I have a cub 2544 that i think uses a similar pump. In the summer i cant really tell any difference in anything i use but in the winter i found that the 5w40 runs much smoother. It whines a lot more with the thicker oils in it when its cold.
 
Originally Posted By: jstutz
I have a cub 2544 that i think uses a similar pump.


The only thing similar with the above 3100 series and the BDU-10 series used in your Cub 2544, is they're both made by Hydro-Gear corp.

Your Cub has a ~6qt sump, compared to the ~1.5qt holding capacity of the ZT-3100's, so they're less apt to have heat related issues.

Joel
 
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Originally Posted By: jstutz
Thanks for the clarification JTK, Your wealth of information is impressive.


Thank you Sir! I'm hardly the info guy.

Just so happened I owned machines with those types of drives; Cub 2544 and a Cub Z-Force 44.

FWIW, the main reason I owned those machines is because of those drive systems. Most excellent indeed.

Joel
 
My small engine shop I use has been in business for over 30 yrs and has been working on them for close to 50yrs. They sell over 9 diff brands of outdoor power equipment so he sees most ever things there is.. They use nothing but syn in these ZT drives.. For one they have never had one problem after changing them over to the syn oil as they were seeing prob with them when using the dino oils.. They do use the amsoil 20w-50 ARO premium protection oil on there service jobs .. but i think the mobil1 15w-50 would be a good choice as it does show on the chart for shearing.. Also on any small engines they get hot and the syn oils will keep them cooler by 10-30F degrees just like the hydrogears the same way.It is recommended by hydrogear to change the filters after first 50 hrs of use of machine then oil and filter every 250 hrs. Good luck and keep the machine running
 
Originally Posted By: lexus114

I wonder if they say that because you would have to spend money on a new unit if it fails? Or if there is truly no advantage to using Synthetic oil in them?


what benefit would there be using a synthetic 20w50 versus a mineral 20w50?
first thing to check would be the viscosity indexes and low temp pump viscosity numbers. what's always accepted about 'synthetic' oil without question is their wider range of operating temperature, and they tend to handle higher temperatures better without oxidizing and breaking down as quickly... but that's a band aid fix. you choose viscosity based on operating temperature, if you exceed what's agreed as acceptable operating temperature then your machine is overloaded, or you have inadequate cooling or a design flaw. but the accepted notion of synthetic somehow 'protecting' better than equivalent mineral i don't agree with, and there's no proof to support that. label advertising does not count. so if operating temperatures are kept in check... then what benefit does synthetic really have (in general and in this application) ?


Originally Posted By: jstutz
I have a cub 2544 that i think uses a similar pump. In the summer i cant really tell any difference in anything i use but in the winter i found that the 5w40 runs much smoother. It whines a lot more with the thicker oils in it when its cold.


that's classic "choose oil viscosity based on operating temperature".
 
Originally Posted By: JTK
Anything between a 15w40 and 20w50 is what Hydrogear specs for the ZT series 2800's, 3100's and beyond. I'd use that M1 15w50 without a worry.

In the event you haven't, the ZT series spin-on filters can be had on Amazon.com or eBay for good prices.

Joel


This is right from the Hydro-Gear ZT2800/3100/3400 service manual:


"The fluids used in Hydro-Gear products have been carefully selected, and only equivalent, or better products should be substituted. Typically, an engine oil with a minimum rating of 9.0 cSt (55 SUS) at 230° F (110° C) and an API classification of SL is recommended. A 20W50 engine oil has been selected for use by the factory and is recommended for normal operating procedures.
 
Originally Posted By: hgh623
My ZTR mower has two Hydrogear 3100 Transmissions. The owners manual calls for 20W50, API SL.
Can I use 15W50? I would like to use Mobile 1 they do not offer 20W50 in standard oil, only in VTwin Motorcycle oil and its API SH.


I would be more concerned about it being an API SL(SM & SN are backwards compatible to SL) than it being a 20W50. Basically all your 15W50 synthetic oils are 20W50 conventional oil replacement.
 
Have anyone tried Mobil 1 0w40 in there Hydro Gear?
I think 0w40 may be a bit thin. The heavier oils tend to have higher Shear/film strength, and the hydros likely work best with the specified high viscosity oil at operating temperature. As of now, Hydrogear actually recommends 15w50 synthetic motor oil. Let's assume they have a reason for that. A synthetic oil is stabile over time (there is virtually no thermal breakdown) and contains zero undesirable contaminants, that can not be completely refined out of dyno oils. Because there is no cat converter involved, there is no practical upper limit on anti-wear additives, such as ZDDP, so you may be able to pick something here with anti-wear additive levels on the high side. You probably do not need a detergent oil, as there are no soot or carbon deposits involved. If you want the best and do not mind the $$, I am guessing something like RedLine may not be a bad choice in the correct viscosity range. Having said that, I advise against adding some aftermarket ZDDP booster product, (blending ingredients is tricky). Given how long the oil is expected to be in there, the cost is probably not prohibitive, no matter what you pick.
 
My ZTR mower has two Hydrogear 3100 Transmissions. The owners manual calls for 20W50, API SL.
Can I use 15W50? I would like to use Mobile 1 they do not offer 20W50 in standard oil, only in VTwin Motorcycle oil and its API SH.
Yes you can use the 15w50 it works great has high amounts of zinc many people use it, I use it all the time in my G730 , these trans axles run hot a synthetic is a must IMO.
 
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