What year? Manual or automatic?
My 1997 4Runner, which is a 3rd Gen 5spd has breathers. Otherwise, you'd blow seals. If theyr'e sealed now, I'd like to understand how they account for expansion of air and fluid inside the transmission as it warms up.
Chris
Not say Toyota does or does not, but you deal with expansion in a sealed unit dy having a void, and a rubber bellows or diaphragm separating the fluid from the void. Void is usually vented air. Fluid depends and pushed diaphragm into void. Anything 5hat gets in the void is separated from your clean fluid.
This technique is used on tons of things from magnetic compasses to hydraulic drives, to transmissions and rear ends.