Cub Cadet Hydrostatic trans oil 

Steve I like your inginuity however, this could become a problem longterm. That Cap is called a VENT CAP. Yeah and many do use it to replace fluid with pump and-or top off fluid to extend tranny life. Vent Cap has two pieces which are attached. Keeps rain out but is made to vent and must breath. If ya still have them put the pieces back together or buy a replacement Vent cap unless your wine bottle design Vents.

Too cheap to buy a little cap that would probably cost under $10? I bet you the bottle of wine you bought to use the cork from cost more than $10

im curious how's that working

@@jamesray9009 used it twice since then and it’s working great. I’m just trying to get through this summer.

Yes there is a internal filter. To access the filter you need to remove the bottom of the transaxle. It’s called splitting the case. There is no pre-made gasket. It uses gasket sealant and it’s a mess of a job. Once the case is split you need to remove all and I mean ALL of the old sealant. The bottom cover isn’t too bad but the transaxle case that houses the pumps and gears must remain free of contamination including small pieces of the gasket sealant you are trying to remove. Honestly I don’t think it’s worth the effort and risk of contamination. If you choose to open the case the filter is easily identifiable and it also holds an additional magnet that you can clean. Putting it back together you will need to follow sealant application to the letter or the pumps won’t build pressure and you’ll also need to torque the two parts of the case to manufacturer specifications.

They start whining just before they fail

amsoil makes trans axle oil.

LOW TRANSMISSION FLUID OIL

Some people will use 15-50 oil since it is easier to find. Specs are 20-50 oil.

Any fully synthetic 20W50 or 15W50 motorcycle oil is acceptable. Motorcycle oil because it has additives needed to keep wet clutches clean.

I had to pour very slow in order to avoid that. I would have used a small baster if my wife wouldn't have caught me taking it out of the kitchen...lol

There is no drain. To replace the fluid you need to pull the transaxle and pop the fill cap off, roll it upside down and gravity drain it overnight. You can’t properly do a fluid replacement with the transaxle in the mower as shown in the video. It requires a specific fluid level and no way to actually see the level of the fluid through the battery compartment.