I've got the five speed torqshift auto transmission. It really sounds like a heat shield rattle but I'll be damned if I could find it. I drive a police interceptor for a living chasing down the bad man and it had the same rattle. Turned out to be the heat shields on the cats.

I brought the truck back to the dealership and they said they found a loose heat shield, claimed they fixed it, but the rattle is still there.

When towing with this setup is it better to run highway with the cruise or the old fashion way?

Thanks for everyone's feedback. It's nice to know people take the time to read post's and respond. In my opinion no matter what setup you run, V-8, V-10, or PSD, the truck is well built and its up to the owner to decide the best combo for his/her needs. I find it funny the people who argue back and forth 'sbetter gas or diesel. All depends on what you need the truck to do.

On a side note, my Crown Vic interceptor is now one of the oldest at my agency. I was involved in a pursuit on mother's day chasing a carjacking suspect in an infinity. We covered over 60 miles often hitting 130mph. Bad guy was caught, infinity was trashed. Crown Vic was purrin like a kitten. I tell ya, Ford's are just some of the hardest working vehicle's I've seen, car or truck!. My agency is switching over to the Chargers with the 3.5 V6, needless to say, I was primary in the pursuit, chargers had a tad bit of trouble keeping up.

 

I found with my 5.4 it was better for me to manage the speed, but I have heard others prefer the cruise control.

 

I use cruise control with our F250 5.4L. On flat interstate with no headwind it'll hold O/D at 2000rpm 65-68mph. Rolling hills or headwinds put it in direct at 2700~rpm. If the hills needs 3rd, I'll slow it down to 60mph and set cruise. Still happy to be back in a Ford!
My previous truck, an '05 2500HD Ram with Hemi, auto and 3.73 had a rattly catalytic converter. It had twin converters like the SD but side by side right before the collector. It only rattled when towing and at around 1700-1900rpm. I never did anything about it once I figured out what it was. Never hurt anything in the 120k miles I had it. I was a little apprehensive about the beating and banging to replace it. A subscription to Sirius fixed it for the most part.

 

My 5.4 does a pretty good job towing my ~7500lb 5th wheel. It has towed it all over the continent and the only complaint I have is range. 200 miles is the average distance I can travel between fill-ups. Shortbed and small tank.

 

on my 2010 F250 4x4 5.4 3.73 first 1800 miles.. power @ 2500- 3000 RPM is excellent with plenty of passing power left too. it is loaded with 1000 lbs(ladder rack, ladders, low rider bed length tool boxes maxed out and misc. equipment in the bed) im getting 12.6 MPG. i hypermiled 1 tank and got 13.3 so i guess its OK in that regard but none the less i love the truck. i did have to do add-a-leaf's in the back to raise the truck up 2". it sagged a good bit which suprised me. does anybody know if the MPG will pick up after being broke in and how much?

 

I don't have cruise control or automatic...

I have plans to add the cruise buttons to my steering wheel, but it still won't shift for me...

 

Failed to mention in my earlier post. I'm driving an '08 F250 CC long bed 4X4 with 4:10's, stock rubber. I much prefer to set the cruise on the highway. That subtle downshift out of OD is much easier for the computer to do to maintain speed. Also, I love the tow mode when pulling! Love the engine braking it employs. It took my wife some getting used to, but when I explained that I'd rather save the brakes for when I need them, she jumped on board with engine braking.