I have got changed my dumba 2004 auto trans oil few weeks ago. it was giving a burning smell. ODO was done 150k. ALLAH ka name le kar change karwa dia (keeping behind all kind of talks about not changing the old burned oil.)
But there was always a question hitting me again and again that how can burned oil helps trans to work effectively and increases trans life? people recommend to not change those oils jo abi market me ana band ho gae hian. but there are many other companies who are making universal ATF.
Anyways i thought before it messes up the transmission. Toyota ATF type t-4 da dial. Only use the recommended oil. its written on the dip stick of transmission.
I would recommend agar oil kharab ho geya hai please go buy this toyota atf t-4 or whatever oil grade is written on your car's auto trans dip stick. take a time. to go proper mechanic get it changed or tran box ki lid uthar k filter saaf kar k new oil dalwa do.
Remember dumba ki auto trans ki gear oil filter new nahi ata and na he change karney ki need hai just wash it clean it and use it again. Gaskit b new nahi ati. people use sliicon instead but if u go to proper mechanic dumba ki original gear box ki gaskit 2,3 times chal jati hai. agar mechanic gaskit kharab na karde.
Still u have any doubt about gaskit and agar need nahi tou dont open the gear box for cleaning the filter. baki its up to you.
Think about it. Good luck guys 
