I looked everywhere I could to find normal/acceptable operating temp of the Dexron in my Yukon without success. Two GM shops told me that 250* was “to be expected” with what I was doing. When I added the new cooler and had the fluid changed two weeks ago the old transmission fluid that had been over 250* at least a couple of times looked fine.
In particular, my experience with the 68RFE is that it will also run 200* in normal driving conditions. The person I hear significantly lower temps from also claims 100,000 miles out of a set of Michelins so they either have/had a real special truck or are full of it. Either way, those claims are suspect at best.
Not saying running cooler isn’t better, but I’m also far from convinced that temps are a weak link in this particular transmission.
Shiner, can you link to a document that states expected or acceptable operating temps for the 68 (or any modern transmission)? I’m sincerely interested.
