Hydraulic drain plug

Mtsoxfan · Apr 7, 2022

While changing my engine oil and filter today, I saw what looked like a push in plug on the transission. It looked like cork, but was hard. Since changing the fluid and filter was next on my list, I wanted to be prepared. It's pretty obvious I need to remove the "cork" and install something a bit more suitable.
Back in the 80's, there was a rubber plug that could be used on a car with a stripped drain plug. Any thoughts on this application?

Roadworthy · Apr 8, 2022

There are still similar expanding plugs out there. While you have your "cork" out you could also see if the hole is threaded. If you're not the original owner it's possible the original owner lost the original drain plug and installed the "cork". On the bottom of a tractor would not be my preferred location for something that could just come out and drain the fluid. If it did have threads and they are stripped investigate a Helicoil or similar as a means of replacing the threads.

Mtsoxfan · Apr 8, 2022

Thanks. I brought it back into garage to look again. It is a cork...
No leaks. I searched with different wording and came across an old thread where Tc tractors were said to have a hole with no known purpose. We'll see when the fluid change happens.

Leejohn · Apr 9, 2022

Are you sure you are looking at the trans or the bell housing? If it's the bell housing that hole would be a vent hole.

Mtsoxfan · Apr 9, 2022

It could very

Leejohn said:
Are you sure you are looking at the trans or the bell housing? If it's the bell housing that hole would be a vent hole.

well be bell housing. Not familiar with tractor components yet. Here are some pics... One shows the drain plug on the other side of belly mower bracket.
I just changed the engine oil, was black as could be, and used Mobil 1 diesel truck full syn oil. Now I notice a leak of black oil. Still trying to figure out where its coming from. Could be clutch pedal or??? Now the new oil is still crystal clear after 3 hours run time. Hydro oil is crystal clear as well. Too far away from front axle to be that. Oh, PS fluid is clear as well. Never leaked before, maybe when I used brake clean to get spilled oil from filter it found a nook to hide in. The area where plug is, is where I'm seeing the oil. It's conceivable it could be from spraying the cleaner. I cleaned this area and will check againafter another hour or so run time.

Leejohn · Apr 9, 2022

I don't know your tractor so I would have to see parts manual to help much. I don't know what I'm looking at in your pictures. If it is a vent hole it could drip for a while from being plugged and a build up of oil. If keeps dripping that's not good, could be a rear main seal.

whitepine2 · Apr 10, 2022

Mtsoxfan said:
It could very

well be bell housing. Not familiar with tractor components yet. Here are some pics... One shows the drain plug on the other side of belly mower bracket.
I just changed the engine oil, was black as could be, and used Mobil 1 diesel truck full syn oil. Now I notice a leak of black oil. Still trying to figure out where its coming from. Could be clutch pedal or??? Now the new oil is still crystal clear after 3 hours run time. Hydro oil is crystal clear as well. Too far away from front axle to be that. Oh, PS fluid is clear as well. Never leaked before, maybe when I used brake clean to get spilled oil from filter it found a nook to hide in. The area where plug is, is where I'm seeing the oil. It's conceivable it could be from spraying the cleaner. I cleaned this area and will check againafter another hour or so run time.

Don't think that is a drain plug, just a cork installed to keep hole clean. Plug to drain looks like plug to left side in one of the pictures, check it out you will be first to know.