if its an automatic then its absolutely necessary because automatics work using hydraulics.
The transmission fluid capacity is 6.9 quarts (it requires Dexron III fluid).
Dexron 3.
if its an automatic change fluid filter in transmission!!
Auto.? dipstick at rear of engine Std.? should be a plug at the side of transmission
yes. check your owners manual to see if it has to be in park or neutral though.
If the 1999 is like my 2001 Malibu. the transmission is a sealed system (no dipstick to check fluid level) and you need to take it to a mechanic (dealer if you have extended warranty).This answer, How_can_you_add_transmisson_fluid_to_1999, might help you to DIY your transmission.
Chevy did not build a Malibu in 1995.
What is the best motor oil to use on a 1999 Chevy Malibu?
approx 8q
My 1999 Chevy Malibu has a fuse box under the front hood,
Remove the transmission oil pan for access to filter
open the cap on the brake mastercylinder reservoir and fill it to the top with Dot 3 brake fluid.