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OC-12 Differential Fluid & Hydraulic System

Gren

Member
We have recently had a lot of work done on our OC-12 including new brake drums, bands, actuator rod sealsl plus replaced axle outer bearings and sealsl The iunit also has a small circulating pump that is powered by the hydraulic system. I have read several posts that seem to give conflicting information about what fluid should be used in the actual OC-12 differential steering housing (depending on the authors take on whether or not it was tied into the main hydraulic system). My manual says Conoco DN-600 fluid should be used and that fluid is also used in the outboard reduction housings. I'm finding a mish mash of information about what the correct replacement for Conoco DN-600 fluid is isince the 600 is no longer available. Any one have an answer?
 

rockhead

Member
I have read (here) that Caterpillar TDTO 30 weight is appropriate. Given that I have put less than 20 miles on my OC12 take that advice for what it is worth. #notAnExpert
 
Caterpillar TDTO 30 is definitely good to use, I used John Deere Hygaurd myself as it was very affordable and easier for me to get at the time. I would go with either of these two fluids.
 

300 H and H

Bronze Member
GOLD Site Supporter
I would definitely agree to use John Deere Hygard tractor transmission oil!!!!


Tens of thousands of Farmers keep it on hand in bulk. :thumbup:

Works wonders in Ag tractors. I would hate to say how many gallons of it we have used on the farm over the years.

Good stuff!

Regards, Kirk
 

Dr. Zaugg

New member
I will also say that you should NOT go looking for the cheapest "they said it was the same" oil. Use the Genuine John Deere oil and you will be very happy with it.
The CHEAP oil is just that. it will not perform in that gearbox.
 
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