trans fluid

i have a 99 chevy blazer with 60,000 miles and i want to change the trans fluid and filter. i have access to free domestic atf fluid. will this harm the transmission or do i need to use dextron

i have a 99 chevy blazer with 60,000 miles and i want to change the trans fluid and filter. i have access to free domestic atf fluid. will this harm the transmission or do i need to use dextron

Yes it may.
Dexron 111 is no longer being made.
Multi purpose and other crap fluid will harm transmission.
Only use dexron/mercon or change over to GM new replacement stuff.
Your GM Dealer can fix you up to it.
If you want to change over or.
Carquest still has a good supply of dexron/mercon.