Originally Posted by martinto
2008 GMC Denali. 6.2L with HD tow pkg rated to tow 7900lbs. Pulling a loaded 6300lb TT with WDH and sway bar. Always use tow/haul mode. Pulled 6% grades over 5 miles in NC mountains with no problem. Heading out west late summer and expect longer hauls over steep grades. Should I consider a larger tranny cooler vs. what is configured in my HD tow pkg?
I'd leave it alone. GMC does a pretty good job at equipping their Trucks to do what they want them to do.
But, I'm cheap.
So if you have any doubts, put on an additional, NOT in place of, tranny cooler. Unless that's what a skilled and highly experienced mechanic tells you what to do.
Have a reputable mechanic do it or study up on it first if you're planning to do it yourself.
Some of them have built-in thermostats and other goodies from the factory that we aren't aware of. Some don't. Some transmissions require a higher operating temperature. Some don't.
Study it. Go to some GM towing web forums and poke around.
Some will say, "Put on the aftermarket oil cooler, it can't hurt"
Yes, it can.