I own a Titan Rock Bits up here in Alberta, Canada and I have always drove F-350 Crew Cabs I have 8 of them in the fleet now and they have excellent trucks. Unfortuneitally I can' t deliver bits anymore due to a smash-up I was in in my Lightning and am now a parapalegic. Anyways, I just bought my brother whom works for me a 2003 Crew Cab Lariat, he picked me up to go to mom and dads to go for dinner and when we left my house and hit the highway he accelerated to 120 Km/h and the truck was at 3700 Rpm and slowley starting to grab overdrive and going in in kind of a soggy way. Now, I will admit Kris beats the liveing hell out of the truck and he drives like a raven loonitick the truck is now a week old and has a inch of mud on it from top to bottom actually theres probily 6 inches underneith and will remain that way until he smashes it up for the first time in approxamately the next 3 months because winter is comeing.
Yes, this truck is abused but he is very popular in the oil patch and makes me and my company alot of money so, therefore a truck is very little to sacrifice.

What would cause this transmission problem? Mud, or the banging and shakeing up and down those rig roads.

Whats your opinion?
I almost forgot to mention when I looked under the truck when we went to leave I noticed there was red fluid on the ground. I called dad and he got the creeper rolled under there and said there was a hairline crack takeing off from where a bolt was tighened.

 

How are the other eight truck's. Does the mud or rig road's affect there transmission's. If not I would say it is your brother's abusive driving. JMO

 

All the other trucks are fine 4 are standards the rest are autos and I have never replaced a transmission in a ford yet.

 

Well I "lost" my 01 tranny at 29K seems to have been a failed main part. Just luck I guess. Mine was not heat related. However does he have a tranny temp guage to montor his so he will know if he is overheating it? He should...

I suspect this is a early 03 with the older style 4R100 in it?