Hydro Gear 104-4310- user serviceable?

[92saturnsl2]

I have two mowers I'm curious whether or not I can change the transmission fluid.

The first is a New Holland LS45. It has a Hydrogear hydramatic trans, has a sticker with these numbers: 104-4310 and 330-3000. Not sure which is the model number. Anyone know if the filter or fluid can be serviced? Is this a robust unit, anyone know anything about it?

The other mower is a Craftsman GT (early '00's model year) with a 6-speed hi/low transmission. Essentially it has three gears with a hi and low selector. I see what appears to be a drain plug on the bottom of it, but I cannot find a fill plug. Anyone know if these are designed with any kind of maintenance in mind? Would be nice to do a fluid change, I really like the transmission on this machine and want to keep it going as long as possible.

Any help would be greatly appreciated.

 

[mattwithcats]

The New Holland has a Tuff Torq K61...
Tuff Torq fills them with 10W-30 at the factory, but says full synthetic 5W-50 on flush/fill...

5W-50 is unicorn tears,
but 15W-50 can be found in 5 quart jugs (Mobil 1 at Wal-Mart)
or NAPA in quarts...

 

[JTK]

The 104-4310 comes up as a HydroGear part number. If it doesn't have a drain plug and a refill plug, which it probably doesn't, it needs to be drained and refilled through the top vent. Have to pull the arse-end off the machine to do it. It's not as bad as it sounds. I would refill with a synthetic 15w40 or 20w50.

In regards to the Craftsman GT hi/lo range 6spd, those used to have a refill plug and a drain, but it's possible the refill had been decontented by the 2000s. You might have to refill through the drain plug. Just jack that side way up in the air to refill. That was the last of the between the knees shift, heavy-duty gear boxes from Sears/Craftsman. Nice units for sure. IIRC, they use gear oil. I think you are doing the right thing for both drives in wanted to change oil in them.