This is a well versed opinion, unfortunately not usually resolved.
I have an 03 F150 5.4 4x4. 35's with 4.56 gears and a 5star SCT tow tune. I rebuilt the tranny a couple years ago (thanks Darrin and others) with some MINOR improvements.
My question is I will be towing about 5500 lb trailer for our Boy scouts. MY understanding of my TOW tune is (watching the tach) 1 -2- 3 - CONVERTER- 4th. I have NOT recieved feed back from 5star YET...but working on that end too.

So towing on 4th gear limitations? Is the limitation the bands torque holding ability? or it's line pressure sensitivity due to the lower RPM's ? I realize STOCK stuff will hunt around ALOT per throttle blip ...i can see that killing one but driving with my tune shows it takes EXCESSIVE throttle change for the tranny to down gear. I have no problem towing with the OD button "off" but would really like to know where the issue lies that limits STOCK configuration trannys that dictates NO TOWING IN OD?

 

I do not know of any limitation that says you can't tow in overdrive. Where did you get that from?

 

I towed a #5000 TT with a 97 F150 with 3.55 gears and 32" tall tires and it was very rare that it would even go into OD.. Going downhill, sure all day long! But, even on the flats, it liked 3rd whether I had OD locked out or not.. The computer and the trans pretty much knew what it liked, which usually did not include OD.. Even with a slight head wind, on the flats, you could not even get it to shift into OD... ha, ha! And if it did, once you gave it any pedal it would down shift anyway.

With 35's and 4.56's, it might be a bit better, but in the end, the computer is gonna downshift you if it needs to anyway.

Good luck!

Mitch

 

basic owners manual....for ANY truck thats why you have a "tow" button....OD lock out button.....od and towing were NOT configured in stock configuration.

 

Fbird -- Mark Kovalsky worked for Ford on automatic transmissions as an engineer for many years. He'd be the first person I'd listen to before anyone.

With that being said, what Mark said above is absolutely correct.

Only time you use O/D off (or tow mode) is if the truck is constantly hunting in and out of 3rd and O/D. Other than that, it doesn't do anything radically different. Even then, as long as your transmission is properly maintained, you will not have any issues keeping it in O/D for the duration.

 

so i c...NOW. That makes sense as the hunting would certainly kill one.
honestly I just glossed over the replies quickly. didn't see the signature.

so it's more of a drive and see....... I can do that. Live , ask, learn!

 

This is from the Ford towing guide:

From another forum:

Quote:

Re: Why is towing in overdrive bad?

Quote:

In Drive the transmission components are locked together. The output shaft is locked to the engine crankshaft, therefore it's turning at the same speed. The transmission isn't doing anything.

What does that tell me? You need to monitor your transmission fluid temperatures and possibly add an auxiliary cooler.

 

excellent info and feedback guys! learning more everyday. Now only 1 question I can't seem to find out (without getting dirty...lol) anyone know what size/threads are on the FORD tranny cooler?
I want to either add an auxiliary or remove original and replace with a larger one. I am NOT a hose clamp kind or person....I would rather utilize quick clip nipples or inverted flare...but thats just me.

 

From what I've heard, if you want to replace the stock cooler with a better one, one from a Super Duty will fit.

 

looks like the 6.0L 2003-2009 is the one everybody "upgrades" to


DORMAN918216
still need to see about adapting lines but...that is NOT difficult

 

I see overdrive bands SMOKED on reverse drums actually warped from towing in overdrive. I have a suspicion that it's from hunting.

So I tell my customers to get friendly with the OD button and haven't had further issues. I tell them to take it out of OD before they actually start to pass or climb a hill, then get settled in on flat ground before engaging it again. I've got people towing WAY more than they should and so far so good.

D

 

Probably the No. 1 thing i instantly noticed with the "tune" is once you get in O.D. ....cruising....you need ALOT of throttle input for the tranny to get back on the converter..which = ...alot less "hunting" during loaded moderate conditions. (it might feel like stepping on a wet sponge due to the lack of rpms BUT..you get nothing for free)
No. 2 ..the BRAKING action of the tranny.....help CONSIDERABLE

 

Speaking of engine braking... I know the SD with the 6.7 PSD has that feature.

I'm surprised Ford hasn't implemented that on the gas variants using the valves. Kind of like a Jacobs brake.

Lack of engine braking on gas vehicles with automatic transmissions is another reason I am looking forward to upgrading to a F-Series with the 6.7 PSD - just for that feature.

I just hate "coasting". I've been driving stick for so long, I expect my vehicle to radically slow down without the use of the service brakes, especially with a load.

 

talking about temps....
Just installed a 40k GVW tru-cool plate cooler (removed my original towing cooler) and installing a temp gauge ON THE TRANNY OUTPUT line ...at the radiator (just before it inters the top of the radiator) what kind of temps should i be looking for. (i will be doing a write up of my install to post a thread) I will be pulling almost 7k trailer thru the foothills in NC. (02 scab 4x4 geared and tuned, 4r70w)
The "thumb" rule i have been seeing on line ranges from outside temp + 100 degrees to..."200 is DEATH" i realize there are many locations to pull temps from and this creates havoc.

 

With the quality of fluids what it is today, 200 definitely isn't near fatal. But, with the right cooler, you should stay below that. Towing will definitely raise temps because the converter is going to remain unlocked a lot.

So see what you get and report back.

D