Scotty, how and when do you think I should change the transmission fluid on 2016 Ford Transit 250 Cargo Van 3.7 L, 6 Cyl. with 39,000 miles. I want to change the transmission fluid at 40,000 miles because I carry a lot of construction materials in the back. The problem is that the transmission is covered with the sub frame right on top and some you tube videos pointed out that there is no way to remove the sub frame without destroying it as the bolts have ceased, which will result in thousands of dollars in labor and parts replacement.

I also called the local Ford dealer and basically they said that they do transmission flush, not fluid change. They do not drop the pan and clean the filter, but rather use a machine to flush it. That's not what I want as I know from watching your videos that a flush damages the transmission.

What do you think I should do. Flush it and hope for the best or do nothing and hope for the best. I am not spending money on new sub frame, parts, and labor every 40,000 miles. If that's the case, then I would rather wait until the transmission dies and then replace it.  Thanks.