Transmission Pan Gasket
The sealing gasket located between the transmission fluid pan and the transmission case to prevent leaks.
The transmission pan gasket is a seal positioned between the transmission fluid pan (which sits at the bottom of the transmission) and the main transmission case. It is designed to keep transmission fluid sealed inside the pan, which acts as the fluid reservoir for the transmission.
The gasket can be made from various materials, including cork, rubber, silicone, or a reusable metal-reinforced rubber. It must withstand constant exposure to hot transmission fluid and the thermal expansion and contraction of the aluminum or steel pan and case.
If the gasket degrades, hardens, or is improperly torqued during service, it will develop leaks. A leaking transmission pan gasket leads to low transmission fluid levels, which can cause gear slipping, erratic shifting, and eventually catastrophic transmission damage due to lubrication failure.
Replacing the pan gasket is a standard part of a transmission fluid and filter service. The old gasket is scraped off, the mating surfaces are cleaned thoroughly, and the new gasket is installed, torqueing the pan bolts in a specific sequence to prevent warping.