Gentlemen,

I have a 2007 F150 4x4 with the 5.4 and was wondering if you recommend turning off the overdrive when pulling a 4000lbs - 4500lbs trailer.

I the past I have always sucked it up in regards to extra fuel and turned off the overdrive but this was in smaller trucks (Explorer) where I was close to (over) the weight limit.

Any advice?

 

If the transmission starts hunting between gears then turn it off, else just let the PCM determine the gear.

 

get some 4.56 gears and ull never have that problem again.

 

Definitly turn it off. I would say anything more then 3k on a trailer needs to have the OD turned off. If you take a chance and not turn it off, when you stop pulling and unhook, your trans could start shifting really hard. And even if you turn it off, if the load is heavy your trans may shift hard for about 100 miles under normal driving. I pulled about 4k with the OD off and had my trans shift hard for about a 100 miles or so after I unhooked the trailer. But for a 2001 cobra with a built long block and built trans that is the new track car, its definitly worth it.

 

what is our towing limit anyways? for: Screw, 4x4, 5.4L, 3.73, FX4/Lariat?

What part of the truck keeps the towing capcity down, engine? gears? axle? tires?

 

Larger rims will drop the towing do to unsprung weight. Gears also will effect it, the long wheelbase will raise the towing, the more power in the motor will raise it, brakes size also determine, and tire size will also due to unsprung weight. There is alot of different things that determine the towing capacity, so I'm not sure what the limiting factor is.
For your towing limit it is in the owners manual in a chart for your wheelbase.

 

How much extra fuel $$$ do you think it will be if you turn OD off? How expensive is it to replace a transmission that bit the bullet early? Turn it off, that's what it's there for. But as said earlier try it with it on if you like, but if it starts hunting, definately shut it off.

I find it a little ironic that when the original poster is concerned about his fuel costs, some people suggest solutions of gears etc, mods that are just huge $$$ compared to any extra fuel cost he may have.

Spend five hundred dollars to save a hundred dollars in fuel?? Must be that new math.

 

Depends on your terrain and wind. I have towed 5-6K pounds for 350 miles at 75 mph (1974 Vette on a caur hauler) with o/d on most of the way. BUT it was very flat and there was no wind. Where I have towed into a head wind or have hills, it makes a huge difference.

Try it out and if it doesn;t shift, you're fine. If it does shift back and forth, then turn o/d off.

 

great responses, thank you. Can Anyone explain the fact that a longer wheelbase increases the capacity? I do agree that is what the charts say that is for sure, I just do not understand why.

Note I have the silly 5.5 box I also never said I was concerned about the fuel costs, I said in the past I have sucked it up and did not use overdrive. Just wanted to know if I needed to turn off the overdrive in my new truck.

 

leave it on the truck will probably get too hot.

I left my OD on when i towed 6500lbs

 

If ther motor is pulling the load with the TQ converter locked in OD then leave it on. IMO wind resistance plays a larger role than the weight of the load pulled. If the TQ converter is locking and unlocking or the trans is hunting gears lock out OD and just let her sit in third. Watch trans & water temps

 

I agree. but if the transmission starts to shift at all, just lock it out of O/D


this is my truck towing a little bit over 6k. in the mountains around Seattle the truck was just fine and towed with 0 issues in O/D on the highway. I had to lock out o/d for the backroads though.




oh yeah, my transmission shifted wierd also for about 10 miles after the trailer was unhitched. I guess it took that long to re-learn normal shift patterns

 

It is based on how it handles. The longer the tow vehicle the better tow it will have. I can't explain it it just happens. I have towed my roommates boat with my truck (reg cab f150) and my roommates truck (Nissan Titan crew cab) His truck handled better.

 

X2 What he said. This is also what the manual recommends.

 

Can Anyone explain the fact that a longer wheelbase increases the capacity?