Fifth Wheel Pulling

I have a new F-350 turbodiesel dualie with positraction and a 4.10 rear end, which will be used to pull almost 14,000 lbs of fifth wheel. I've been told by "knowledgeable" people that I should not pull this amount of weight with my truck in overdrive. I have found in the couple of times that I have pulled my RV that the automatic transmission in overdrive tries to "hunt" for the proper gear moving back and forth.

These "knowledgeable" people tell me that running without overdrive will keep the rpm's up and will prevent this shifting. Common sense also says that my gas mileage will go down if I do this, and the engine will be running "harder" than need be in overdrive. I simply do not know, and would appreciate your input.

2002 Ford F-350 turbodiesel dualie
2002 Newmar Kountry Star 35LKSA

C Nash

Senior Member
Fifth Wheel Pulling

Hi buckbs,
I would not recommend towing this much weight in o/d. Go with whatever your ford owners manual suggest. It would probably be ok on some level ground just, listen to your engine for lugging. Probably will not affect mpg much if any. The trans will tend to slip more in o/d which creats heat and heat is what destroys most transmissions. Remember this is just another opinion.
Fifth Wheel Pulling

While I would not want to second guess your owners manual. I would not be bothered using OD in flat to rolling country. IF your transmission starts hunting (in and out of OD) shift it out of OD. Shifting back and forth creates alot of heat. My current unit weighs in close to 31,000 lbs (Not counting the toad) when road ready and I always run it in 6th which is a second overdrive. Rarely will I kick it down to 5th manually which would take a pretty good hill to cause me to do so. Good luck...
Fifth Wheel Pulling

I have a setup similar to yours except a few years older. I alway tow in OD when on level ground and haven't had any problems. As others suggest I lockout the OD when in hilly areas or if the tranny is hunting.


New Member
Fifth Wheel Pulling

We have four F-450 dually tow trucks in our fleet, and they all have the E4OD trans, and we turn the OD off when towing in hill or mountain area's. General rule of thumb is, if the trans is searching, then you shouldn't be in OD. To let it continue to search, will burn up the OD, and then you'll be in a world of &%$*!

Look at it this way, a little more spent on fuel now, is a lot cheaper than a new transmission next month!