First thing I need to say is I would like to thank Mark Kovalsky. Thank you. Thank you. Thank you. You saved me from many mistakes and helped me find the right direction.

I have a 2003 f250 with 7.3 and 4r100. I don't tow. I sold my trailer before buying this truck.

I have many questions. Searches as a nonmember yielded 100s if not 1000s of results.

I'm planning on following Mark Kovalsky's advice on a transmission flush. My truck has approximately 189000 miles. Runs and shifts good. Just upgraded to the 6.0 cooler.

My questions:

Should i drop pan and change filter when doing the flush? I'm the third owner and don't know history of transmission.

How often to flush? I'm open to doing oil analysis but need some guidance.

I'm going to add dieselsites external filter. Is this unnecessary?

I read the old version of the flush procedure and purchased 20 qts of valvoline Dex/Merc. OK to use this fluid? I think it's too late to return.

Thanks in advance for any advice.