Tractor hyd. fluid in th350

bigs10blazer · Oct 27, 2016

we just did a rebuild on th350 trany on my sons bouncer and used 303 oil, seems to work great and hopefully for a long time, also i just changed tranny fluid in the jeep th350 and i put 303 in there , plus i put it in the steering pump all so ( i usually use b&m trick shift and tranny fluid) in the steering, although it works great, im trying the 303 out to see if it works,

June dog · Oct 27, 2016

Mine didn't work out to well. Trans went out on second trail in Harlan on the first day there. Got a rebuilt trans ready to go back in its place. I'm going to use a good synthetic in this one. Im Afraid the 303 will void my warranty. The trans guy did tell me one thing that I wasn't aware of. He said if your fluid gets over 220 for over a 5 minute period that it looses all its lubrication properties. He said it doesn't protect any better than haveing straight water in it. He said to get the fluid changed out immediately.

ranger11 · May 15, 2019

Bump

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mac5005 · May 16, 2019

There are so many AW hydraulic fluid viscosities but only a few are similar to dex3merc

I have some related info on this, I'll have to find this evening.

Even in the same AW/ISO grade different brands have very different properties hot/cold.

What is also important is to look at the viscosity index #. The higher it is, the more consistent the viscosity is between cold/hot and the more expensive the fluid will be.

That also doesn't mean the more expensive brand is better. But a higher viscosity index is generally more expensive oil bc it's better.

This equates to the fluid not breaking down as fast at higher temps and losing its lubrication properties and it feeling more consistent at different temps.

RustyC · May 16, 2019

I run Caterpillar 10w transmission/drivetrain oil in both my offroad rigs th350s, my sons 4l60e and my 4r100 in my superduty. All with big coolers. No issues at all. Cat part # 2487521

Bebop · May 16, 2019

Jduck said:
Everything is working like its supposed to. I was fighting high temps the first trip out just like all the previous trips since I put that converter in. Added a huge trans cooler in front of the radiator and now it barely gets over 150*.

Details on that cooler you're running now ??

Jduck · May 16, 2019

Bebop said:
Details on that cooler you're running now ??

This was the cooler I put on it. https://www.amazon.com/Tru-Cool-LPD47391-Pressure-Transmission-Cooler/dp/B0060NKA1U

Dirt700 · May 16, 2019

I have been using Kendall hyken 052, but I also lost 3rd gear, don't know if it is related or not. Once I get it rebuilt may go back to 303 and I'm going to put a bigger cooler