You put that in your exhaust to help keep it from escaping into the atmosphere. You should also probably make sure that your transmission sand level is reading about a foot above the line that says full since it's often the cause of your exhaust plug falling out.
hw did you know my engine and tranny are out of a 71?
and no, no leaks.
after 20 yrs of tranny drips i finally brought it in.
a whooping $350 for some seals and band adjustments
holy Christ, i spent more than that in fluids topping it off every week