New Z121S

[mickeyd]

I just got the wife a new Z121S.

While going over the manual, I was amazed to find that the Transaxle uses "Engine oil: API service Classification SL SAE20W-50" instead of hydraulic oil.

Any other Z121 users out there have a recommendation on which brand oil to use?

 

[lugbolt]

I am NOT starting an oil war. They come pre-filled with a synthetic 20w50 and that's all I'm saying about it. Bad Boy among many others use the same transmissions. I have personally tested/used many different types/brands of 20w50 and there is zero difference between any of them. The Z121 HST's? That's the one part of a Z121 that I have not gone into, period. To me, they're bulletproof. Leave them alone and use the mower as it's designed to be used and don't overthink it and IMO you will never have an HST problem.

 

[Daren Todd]

Not trying to start an oil war Just a comment about pricing. When I went to service my Z121S, i stopped by the local kubota dealer for filters. Also needed parts and filter for my in-laws four wheeler. They happened to be the local Yamaha dealer as well.

I almost bought the oil I needed for both the mower and four wheeler from them. Till I saw the prices. Then I about fall off the stool at the parts counter I said never mind, I'll shoot across to the auto parts store for the oil. Kubota was pretty proud of there 20w50.

Valvoline, mobile 1, chevron, Quaker state are all good oils. All have to meet the same standards for today's equipment. Even the store brand oils are good.It just what you are comfortable paying for price and personal preferences.

 

[mickeyd]

Sorry, I didn't mean to start "an oil WAR."

Thanks for the replies.

What struck me the most, was that it was neither hydraulic or gear oil.

 

[North Idaho Wolfman]

Older Bobcats use motor oil in all of there Hydraulic systems too, it struck me as odd also, but it's to keep the drive motors clean as the Motor oil has a detergent in it.

I will second or third, I might have lost count, Good quality synthetic 20W50 motor oil.

 

[Russell King]

Sorry, I didn't mean to start "an oil WAR."

Any time someone asks about oils there tends to be slightly differing opinions vociferously expressed. Thus the fear of reprisals is great for any statements on any oil subject.



Sent from my iPad using Tapatalk

 

[mickeyd]

I am having trouble finding a Full Synthetic 20w50 oil except for "Lucas Racing Oil" at $171.99 for 5 gal.

 

[North Idaho Wolfman]

Castrol, Valvoline, and Mobil have it too.

 

[eserv]

Older Bobcats use motor oil in all of there Hydraulic systems too, it struck me as odd also, but it's to keep the drive motors clean as the Motor oil has a detergent in it.

I will second or third, I might have lost count, Good quality synthetic 20W50 motor oil.

many older tractors used motor oil in their transmission and rear ends. Both Fiat and David Brown for sure as I worked for them back in the stone age! I also worked for a few years repairing hydraulic systems on oil rigs, the ones that used motor oil gave very little trouble! In my opinion motor oil is a very good hydraulic oil and usually is much cheaper too.

 

[lugbolt]

I have used UDT and Super UDT in transaxles (hydrogear) in the past successfully. They're still working to my knowledge. Have also used Super UDT in power steering on my old Mustang. That system runs hotter than SUDT is designed, thus it burns and stinks to high heaven. Went back with ATF. Have also used engine oil (5w20) in automatic transmissions and it works but converter stall speed drops off a little and it's a little sluggish at cold temps. As far as using engine oil for hydraulic? At $5.00/quart (average price for engine oil unless you buy Fred's oil at $1.50/qt on sale), it comes out to $100 for 5 gallons which is more than UDT and more than ISO46.

 

[mattwithcats]

Tuff Torq, who makes the K46 transmission for small riding mowers, has the same recommendation.

Lots of people use Mobil 1 15W-50 in the K46 with good results...

The only difference is viscosity when cold, it’s still a 50 weight when hot...

https://www.walmart.com/ip/Mobil-1-15W-50-Advanced-Full-Synthetic-Motor-Oil-5-qts/20713647

 

[mickeyd]

Castrol, Valvoline, and Mobil have it too.

What I meant was "having trouble finding someone local that sells it." I can find conventional 20W-50 oil most anywhere.

I tried AutoZone, Advance Auto, Napa & Walmart with no success.

I took Matt's advise and used 15W-50