My 4610 has a filter for the hydraulic and one for the transmission. My last tractor was a Case IH (mitsubishi)
24 HP gear transmission. The ONLY filtration for the hydraulic oil, which also bathed the transmission was a single bronze screen. I was not impressed to say the least. It did not fail in 600 hours of use, but I never let the hydraulic oil go more than 100 hours without a changeout. I used Shell Donax TD
bought from a bulk plant, never considered synthetic on it because I didn't want to extend useage if the fluid wasn't well filtered. Keep it clean by changing it more often and you shouldn't have a problem.
