alpinecrick
I'm Awesome
Thank you for the clarification with the nomenclature.
I have just changed the fluid recently. It had not been changed since the van got a new 4l60e ~40k miles ago and while it was still red, it did smell a tad burny so I got it changed as soon as the new filter came in. Have driven about 200 miles or so since and still shifts firm and have no issues.
I'm still definitely considering slapping on an external cooler anyway. Would having it run in between the return line from the stock cooler and transmission work fine? Would still utilize the stock cooling power and the hypothetical secondary cooler.
Yes, that's how the factory does it. Into the auxiliary cooler in the radiator first, then out to the external cooler, then back to the trans.
And as df mentioned, the auxiliary cooler (which is really a heat exchanger rather than merely a cooler) heats the fluid when cold and brings the trans up to temp.
I mention the GM nomenclature thing because when folks start posting about the auxiliary vs the external coolers I have watched threads become one of those hysterical "Whose on first base" kind of threads.........