I think I found the transmission filter location. It's under the right foot area (when driving) and opposite the transmission drain plug. It has a metal line/hose about 1" diameter coming out of the middle and is secured by 3 small bolts.
Yes, that's it. Is yours leaking? The photo kind of looks like it might be leaking. Not that it makes any difference, you'll be resealing it.
So first drain the trans/hydraulic fluid, and then disconnect the center hose and undo the three bolts. Pull the cover straight off. The tubular strainer will either come with it or need to be fished out. If the tubular stainer screen it is so clogged up that it looks like it has a solid surface a solid surface instead of being a screen then you've found the source of your hydraulic noise problem. Clean the screen with a soft brush & soapy water, dry, and slide it back in. Keep in mind that this is just a crud filter, nothing special. If yours is damaged, you may be able to repair it. It won't hurt to try.
You often have to play with it a bit to get it back into position so that it fits into the transmission right so that the cover can be tightened down without smashing the ends of the screen. If that happens, just straighten things out and start over. It's easier if you lay the tractor over on it's left side.... well, just kidding, but it would be easier.
The three bolt cover originally had a gasket - shaped just like you would think with 3 holes for the bolts and a central hole for the oil to pass into the take-up tube. Ifthe gasket is shot - and they usually are, I just make one from gasket paper & coat it with a favorite silicon gasket maker. In my shop the current favorite silicon is something like Permatex gasket dressing or Form-a-Gasket. In fact, all those silicon gasket sealers seem pretty similar to me. Then I hang the the gasket on a hook for an hour to let the silicon "surface cure" so that it is still rubbery but not sticky. Then bolt every thing back together. Don't forget to refill with new oil.
Since this is a suction side filter that feeds the hydraulic pump, the cover doesn't see much if any positive pressure. If it doesn't leak when bolted up and refilled then it never will. You are good to go.
Good Luck,
rScotty