I recently bought a 2006 gehl ctl60 at auction. It has 1200 hours on it so I wanted to change the hydraulic fluid. The service manual I have as well as the Owners manual I downloaded call for 10w30 diesel engine oil for the hydraulic system (10 gal). This sounds strange to me. Has anyone run across this? thanks Jon
Takeuchi has always called for 10w30 motor oil for their hydraulic systems. Here, I only have 8 Takeuchis, only some with 10k hours or more, and ever since the first change, I've run 10W TO-4 Hydraulic oil in them. Never an oil related issue.
All the older Case 1800's used 10w30 in the hydraulic system. Worked in the engine and chain cases too. The idea was 1 oil in everything.
So did you have to do a purge on the first oil change to clear out the motor oil before using the 10w to4 hydraulic oil?
Nope. Just mixed it in. Even had a brain surgeon here use that 10W in a 6059 Deere. No issues there either, save for higher oil consumption until changed out. Even with 10 wt oil, on a 20° day, if you rev fully without a little warmup, the pilot pump filter can collapse, but, youll know it because the hyd filter light flashes even after warmup. And, if you're really good, go full throttle on a 10° startup, before allowing some warmup, and you too can smear the piston skirts up and down the walls of the engine bores.
We were just talking about this in a recent thread. Yes Takeuchi has always spec'd 10w30 or even 10w40 for the hydraulic oil. Gehl even had the decal stating so. From my quick research, the to4 appears to have a lower viscosity index than 10w30 engine oil. That would matter more in colder weather. And has lower viscosity at high temperatures. I'm still not sold on the idea of using t04. You can buy large buckets of the diesel engine oil at your local farm store.
Thanks for this info. This machine is just going to be a homestead machine, so I'll just go the easy path and use 10w30