To stop your transmission from leaking, first, identify the source of the leak by inspecting the transmission pan, seals, and gaskets for damage or wear. Tighten any loose bolts or screws and replace any worn or damaged components. Additionally, ensure that the Transmission Fluid is at the proper level and use a sealant designed for transmissions if necessary. If the leak persists, consider consulting a professional mechanic for further evaluation and repair.
If a transmission is leaking fluid, it is likely that a seal or gasket has failed. Replace the gaskets and seals and the leaking should stop.
You don't.
Because your transmission has a seal that is leaking.
The better question is what is leaking transmission fluid?
It 12 years old you should have it serviced perhaps the seals need replaced, an are sure it's the Trans leaking and not the engine.
No, thay have never made anything in a can that will fix something. If you add stop leak to your transmission it will mess up the seals and you will have to have the transmission rebuilt. It would be best to just fix the leak and a whole lot cheaper.
Could be a gasket, an o-ring or a seal. Need more info as to where it is leaking.
The output shaft seal has failed and transmission fluid is leaking by, and that would explain the transmission fluid appearing there.
Rear main engine seal or front transmission seals
You need to check the transmission gasket between the transmission pan and the body. If it's leaking you have to replace it.
why do toyota sienna transmission leaking after change a new transmission and ran 5000 miles?
The pan gasket could be leaking ( tighten mounting bolts or replace gasket ) Filler pipe rubber seal , Transmission oil lines ( tighten , replace ) Speedometer connector ( replace o-ring ) Some makes have a transmission vent pipe ( transmission over filled ) Output shaft seal damaged (replace)