Posted By mitchman on 27 Jun 2012 12:18 PM
A Little Off Topic:
Our 2005 F-150 FX4 (4WD) has the stock tow package. I installed a trans temp gauge and I'm glad I did. While towing 3500 lbs over a mountain pass, the trans temp can reach 200 degrees or more if I let it. But with the temp gauge I can keep an eye on it and choose the appropriate gear. I'd love to upgrade to something with a 6-speed transmission because I think it would help. Right now, the temp rises when ever you're "between gears". The way I understand it the torque converter will unlock giving you a gear between 2nd and 3rd. If I can prevent it from unlocking, the temp won't build.
Do what he did. Start with a transmission temp gauge. If you're dropping the pan upgrading to a high capacity (mag-hytec I think is a company that makes these) is not a bad idea... more fluid=a lower percentage of contaminates, slower to temperature increases on the long hill, etc. Best of all, unlike an actual add-on cooler, you're not introducing additional failure points to your tow vehicle.
If your transmission is still running hot, then I'd look into an aftermarket cooler.