Have a jd 445 and there is a round canister on the rear end right above the oil filter that is leaking hydrolic fluid. Its round and has fins on it. Almost like a resivor or something like that.. 1st can anyone tell me what its.. and if I can unbolt it and just put a gasket in? Any have a diagram of what it would be.. thanks..

Randy
That's the hydrostat transmission.
The easyest way is to remove the whole transaxle and trasmission all togather,If you go to john deere parts catalog,you can get a parts breakdown.
Luck

Do you just have to unbolt the rear end ? Dose it come out as one big unit? Or is there a lot to discontect? Thanks.. I did look it up and it calls this canister the motor? Is that the hydrostat?

That's the Hydrostat
You have to undo the hydrulic lines .undo the foot control linkage
The brake control the differential lock control.theres a few switch wires to undo.First thing you'll have to take off the seat and fender deck , then remove the fuel tank.
Luck

One more question. When I unbolt that houseing is there anything to worry about falling out or will it just come off without losing anything inside? Thanks for your help

When you split it there is a gear, but it shoulkd come off with the hydrostat,but be ready it is heavyer than it looks.
Luck