The 1988 Ford Ranger 2.9L V6 4x4 does
not have a transmission dipstick. Automatic transmissions in that era usually did, but many manual transmissions (especially in 4x4 trucks) did not. You check the fluid level in the transmission by removing a fill plug and checking the fluid level inside the transmission case. This is more complex and generally requires removing the transmission case and then looking at the level.
Therefore, you should consult your owner's manual for the proper procedure to check the transmission fluid. Trying to find a dipstick where there isn't one will be fruitless.
