I have a 2003 550 PSD with 4r100. I have a Gear Vendor over/underdrive also

I have always been concerned with the trans because of other post and research.
My truck weighs about 12,000# and I occasionally tow a 10,000# trailer.

A couple of times when I first start the truck a hear a screech or high pitched whine, seems like it's coming from the tranny but almost sounds like a belt slip?

Most of my driving is in the low desert in California (110-120 degrees). When pulling a grade without trailer I have reached 205-210 on my trans temp guage. Is this to high? What type of trans cooler with fan would be the best and where would you locate it?

I intend on having this truck for 500,000 miles so I am always looking for anything to increase it's life

Any Help?

 

With that type of load every day, and pulling to boot, you WILL need a new tranny at some point. Heat is the killer in trannys, and you get that from ambient temperatures and loads. The Superduty has an integrated tranny cooler, but when your tranny does go (and it will) you should go here:
http://www.suncoastconverters.com/index.html

 

I installed the suncoast tourqe convertor and did the upgrade to the transmission. That solved any overheating problems with the transmission. When I drilled the holes in that plate to port the transmission I got 2nd a little big. I could break the wheels loose with a load on if I was standing in it. It seems to have solved the problem because I have 180k on the transmission since I did it with no problems. Took out two transmissions in the first 80k miles on the truck. F450 superduty 4x4 with 488 rear.