I need a little advice fellas. I just bought a 2003 F250 with a 7.3 PSD. Long bed and auto trans. This is the first diesel I've owned. I'm going to be towing a fifth wheel trailer weighing about 8500-9000lbs. ON flat road do I need to tow in drive or can I use the overdrive? My gas rig I could'nt use the overdrive. Any help would be appreciated. Thanks in advance!!

 

OD will be just fine. No need to turn it off for what you are doing.
However, you may benefit by turning it off when you are taking an offramp or driving on surface streets. There will be some engine braking benefits with OD turned off so that is nice to have when towing from stoplight to stoplight.

Happy towing!

 

You're OK to tow using OD UNLESS your transmission keeps shifting in & out of OD. I'd also lock it out for any steep grades, more so for uphill, but downhill it will give you more engine braking benefits. You can also put in a manual switch to use the factory EBPV as an exhaust brake.

 

Your truck will pull 9000lbs like a champ. Enjoy the tow! Just turn OD off if the transmission is hunting for gears between 3rd and 4th gear.

 

Have any gauges? If not, i recommend, the egt, trans and fuel pressure gauges, possibly, if going to the 4-A pilar set-up, the oil pressure or oil temp gauge.

 

I suggest you always start out with the OD locked out until the RPM gets up to around a normal operating amount. The tranny will slip less and generate less excess heat. Heat over a long period of time kills the transmission. Also, if you go an extended distance on a steeper grade, you might even want to back down a gear for the same reason. Take it from someone who knows - losing the tranny on a steep grade is no fun. I lost mine pulling a 24' enclosed trailer full of marching band equipment up a steep grade behind two bus loads of band students. I had the OD locked out, but i was going at reduced speed. I would have been better off to have went on ahead at a higher speed, but I was staying with my group. The engine revved up and the truck stopped pulling. I had to let the rig roll backwards down the hill to get it off the road. Like I sad, NO fun at all. I'm not sure how the '03 transmission is different than my '00, but I'd recommend doing everything you can to make the tranmission's life easier BEFORE a catostrophic event occurs. It can't hurt, right? To me it's like having 4x4 and not using it, and bragging that the truck made it through "without even having to use the 4x4". Until one day, you slide off the road down an embankment....

 

Add additional cooling capacity for the trans oil to your truck. The trans will thank you for it.

There are a couple ways to do it, but a lot of guys here replace their stock oil-to-air (OTA) cooler with one from a later-year 6.0 liter SuperDuty.

Some just add another aftermarket cooler in series with the fluid cooler lines.

Pop

 

I agree with POP! Add a extra cooler not hard to do and not expensive! I just put another cooler in series mounted to the AC Cond. Pullin my 34ft fiver to Fl I never saw a tranny temp over 170 deg. I also agree with the other posters about gauges! Get some will give you better picture of whats going on when pulling your load!!

Smokie

 

x3 on the extra transmission cooler and a tranny temp gauge.

You have no business going without those items unless you want to go see John Wood or BTS soon.