My thoughts on replacing the cork gasket, I don't care to lay under a cub because I'm 60 years old. Here is the way I do it.
1. Remove the battery, two bolts and tie down if you have one.
2. Remove the seat, two bolts on one side.
3 Remove the 4 bolts in battery box.
4. Remove the foot pads, 8 screws.
5. Remove the lift height adjustment knob.
6. Disconnect rear lights if you have them.
7. Remove the transmission cover, 4 screws.
8. Remove the fenders.
This doesn't take long and then you can do a thorough cleaning on the underside of the fenders and the entire rear end.
Pull the rear gasket, drain the hydro fluid and clean the inside of the rear end. Make sure to blow through the breather top back of the rear end to insure it is not blocked.
Disconnect the rag joint, clutch return spring, hydro controls, then remove the bolts holding the rear end and hydro.
Take the hydro and rear end out and tip on its back, remove the hydro, and replace gasket.
I make my gaskets out of Neopreme using a cork gasket for a pattern. I get the Neopreme from an auto parts store near me. I use the 1/16 th inch and have never had any problems with leaking. I have had pieces of Neopreme soaking in hydro fluid for over a year to see if there were any problems and have not seen any swelling or ill affects.
This is a good time to replace Rag joints and the busings front and rear if your particular cub has them.
Reweld the trunion bracket if there is wear and return it to its original size. Lay the side bracket over the trunion bracket and the area where the springs go should be identical when you are done. I always replace the tips that the springs go into. Springs are usually good.
Replace the hydro and rear end. Install new rear gasket, filter and hydro fluid. With the rear end up on jack stands make the hydro control adjustment per the manual. Use caution not to get hurt while performing this function.
I have been painting my foot pads with the truck bed liner that you can get at Wal Mart and really like the results. Gives a nice appearance and not slippery.
Not saying this is the only way to do it but it works for me. Not inteded to replace the instructions in your manual.