ATF replacement

Can you elaborate on this tow package exchange or have a link?

 

The tow package runs the tranny fluid through the cooling system, I haven't looked it over, but I assume there's a simple hose to pop off.

 

Do the drain-and-refill change and measure what came out: refill with same amount. 30,000 miles later do it again: You end up with about 8-10 quarts of refreshed coolant in there if my memory of the posts here is correct. Maybe drop the pan at 90k for a sanity check if I wasn't the original owner and didn't know the history. Personally, I wouldn't do the flush-and-fill change if my truck had 180k but I also don't believe it will tank the transmission either: unless it has been abused or lived a lifetime towing in the mountains. My truck had no evidence of ever towing anything: pristine factory hitch receiver and the trailer cable connector cover took some effort to open it when I checked it. I think I was the first person to open it.

 

I would ask over in the 1st Gen section those guys may know more?

 

I got it sorted. Drained it (2 quarts) refilled it with the same amount. Drove fine. Drained it again and refilled it. Perfect now. Good level and color