Towing in OD - 2004 F150

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XJ1100

Joined
Feb 28, 2005
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94
Location
MN
2004 F-150 4.6L w/ 4R70 and 8.8" rear (currently 47,000 miles)

Towing 800lb. trailer + 1000lb. load for about 200 miles round trip on the weekends. I have read that the weak point of this tranny is the OD band and that towing with OD on can cause problems with this. The question is if I am towing at 70 mph should I be in OD or spinning the engine a little faster w/o OD. I am not concerned with the engine as I am positive it will never give me problems. I am debating because I have always thought that towing w/ the OD off would cause higher transmission fluid temperatures (no converter lock up) but also do not want to cause damage to the OD band in this transmission by towing with the OD on...? Is this load light enough that it shouldn't really matter either way?

My thoughts are that if it stays in OD and isn't constantly down shifting to tow that way and take OD off only if it is always shifting to a lower gear.

What would all the BITOGers do?
 
The TC doesn't lock up one gear down from OD?

If you can tell when it's in TC lockup on OD, and that isn't constantly changing, then it's probably a light enough load not to matter. I would take it out of OD if you see the TC locking and unlocking constantly, or constantly changing gears.
 
1800lbs is not alot of weight. I've been towing toys (snowmobiles, atv's boats) 1000-6000 lbs tens of thousands of miles for over 20 years. I have never had a tranny problem and even when towing the 3300lb boat I do not lockout the overdrive. The only time I lockout overdrive is when towing the heavy boat 6000lbs. do you tow mostly on flat roads?
 
Originally Posted By: XJ1100


My thoughts are that if it stays in OD and isn't constantly down shifting to tow that way and take OD off only if it is always shifting to a lower gear.

That's what my Dad does with his 2003 5.4L F150 pulling a 28' 5000lb camper trailer. It will hold in OD at 70mph up slight slopes but if the transmission starts hunting then out of OD it comes. Into a very strong headwind sometimes its out of OD all day.
 
I'm pretty sure it locks in 3rd gear or 4th if it's a 5 speed.

Definatley spin the engine a few more rpm and keep it out of OD. The strategy is usually to unlock the convertor first, generating a lot of heat. If it still can't maintain speed, it will downshift but it may just relock the convertor in the next lower gear. Running more rpm produces a very small amount of extra heat in the trans. Running it at heavy throttle with the convertor unlocked in OD produces a ton of heat.

Don't always trust the factory shift logic. Going up the grapevine, my TL will pull it in 5th with the convertor unlocked. When I manually pull it down to 4th, the convertor will lock due to less throttle and the rpms are exactly the same as 5th unlocked and I'm generating much less heat.
 
It's a 4 speed auto in my Dad's truck. I don't think the converter locks in 3rd gear only 4th. I should have said that once the truck can't hold 4th locked he puts it in 3rd or uses the tow/haul mode. I guess even just raising the rpms in 3rd even if its unlocked helps the torque converter be more efficient.
 
I do tow on mostly flat ground and the truck will hold 4th w/ converter locked @ 70 mph. I don't think the converter locks in any gear other than 4th...unless someone knows differently with this transmission?

BuickGN - You are saying that anytime the converter is unlocked it will produce a ton of heat, correct? This is how I understand it also, and thus why I would not want to be cruising along at 70-75mph w/ high torque going through the converter.
 
Originally Posted By: IndyIan
Originally Posted By: XJ1100


My thoughts are that if it stays in OD and isn't constantly down shifting to tow that way and take OD off only if it is always shifting to a lower gear.

That's what my Dad does with his 2003 5.4L F150 pulling a 28' 5000lb camper trailer. It will hold in OD at 70mph up slight slopes but if the transmission starts hunting then out of OD it comes. Into a very strong headwind sometimes its out of OD all day.


Your dad's truck has the 4R100, the same as my '02 Expedition (the 2V 5.4's were always mated the the 4R100 AFAIK) which is a completely different tranny, rated for 1000lb-ft in all 4-gears and can handle full-power upshifts through all 4 as well.

There is no advisement in the manual to take this transmission out of O/D when towing.
 
Originally Posted By: OVERK1LL
Originally Posted By: IndyIan
Originally Posted By: XJ1100


My thoughts are that if it stays in OD and isn't constantly down shifting to tow that way and take OD off only if it is always shifting to a lower gear.

That's what my Dad does with his 2003 5.4L F150 pulling a 28' 5000lb camper trailer. It will hold in OD at 70mph up slight slopes but if the transmission starts hunting then out of OD it comes. Into a very strong headwind sometimes its out of OD all day.


Your dad's truck has the 4R100, the same as my '02 Expedition (the 2V 5.4's were always mated the the 4R100 AFAIK) which is a completely different tranny, rated for 1000lb-ft in all 4-gears and can handle full-power upshifts through all 4 as well.

There is no advisement in the manual to take this transmission out of O/D when towing.

Hmmm, do you have the tow package on your truck and a tow mode? I haven't driven his truck in a while but I think all the tow button did was keep it out of OD locked up and raise the shift points a bit. So the way I figured, it would be better to just run in 3rd with less converter slip than 4th unlocked? In 3rd at 60 mph its still only around 2200 rpm.
Whatever he's doing seems to be ok as they've towed their trailer probably 20,000 miles in the last couple years with no problems.
Its good to know the tranny is plenty strong too, I had a quick look in the F150 forums and didn't any posts on trans problems.
 
No, there are 5.4L 4R70W around, OVERK1LL. It is a method of getting a slightly better trans by ordering a reman 4R70W for a 5.4L truck and installing the car VB. It has a stronger gear set among other things.
 
Hold the gas down with your right foot in 3rd under cruise then tap the brake with your left. Most trannies unlock TC when brakes are applied and the revs should raise.
 
Lots of 4R70's mated to 5.4's Overkill. Besides, he indicated he has a 4.6, which was always mated to a 4R70 in the F150 in the earlier generations.

Regardless, if the tranny isn't hunting in and out of OD, tow with it there at 70 mph and rest easy. 163,000 on my previous F150 and 179,000 on my current '99 F150 4.6 with the 4R70W towing that way. I've towed trailers in Minnesota and Colorado and points in between with this - and there are definitely times to take it out of OD, but most of the time in MN, leaving it in OD is just fine.
 
Originally Posted By: Onmo'Eegusee
No, there are 5.4L 4R70W around, OVERK1LL. It is a method of getting a slightly better trans by ordering a reman 4R70W for a 5.4L truck and installing the car VB. It has a stronger gear set among other things.


Huh? Are you talking about ordering a "truck" 4R70W and installing it in a car with the car VB?

It's been a long time but the only differences I saw between some of the heavy duty units and non heavy duty units were valve body calibrations and sometimes the sprag clutches would have more sprags.
 
Very interesting. I wish something like that were offered from the factory for my car instead of paying $3,500 for a trans with billet parts that will hold up and that's not including the TC.
 
Yea, that sucks. A buddy of mine just built a 4R70 for a 700 rwhp Whipple Cobra. He used a '02 5.4 2V 4R70 trans, and basically stacked clutches and used spiral locks where he could, used a PA MVB, and a custom converter with a diesel converter clutch setup that is being locked up in 2nd and 3rd at WOT. The setup is nuts and was about $3000 including the ~$1000 converter.
 
That sounds like a nice setup. $3K trans and convertor is real nice.

I used to also lock the convertor at WOT in second and third. As power levels went up I started frying the stock convertor clutches. I even ran a multi disk lockup for a while. 9" convertor with an 11" clutch.

I discovered two years ago that you can make a non lock convertor much more efficient than a lockup. I'm running a non lockup convertor for the first time in the 15 years I've owned the car and it's awesome. It's only got 2-3% slip at WOT above it's stall rpm. One thing I really like is it allows a turbo car to spool the turbo much easier on the line without torturing the convertor. It doesn't grab much at all under the stall speed and then grabs very efficiently as it approaches the stall speed. It's great for a car like mine that would have trouble building enough boost to get the convertor to it's stall speed. Now those pesky Mustangs can't play the game where they leave me sitting at the line on full boost heating the intercooler up while they take their time to stage.
48.gif
 
Originally Posted By: Onmo'Eegusee
No, there are 5.4L 4R70W around, OVERK1LL. It is a method of getting a slightly better trans by ordering a reman 4R70W for a 5.4L truck and installing the car VB. It has a stronger gear set among other things.


I knew the 3V came with it, but for some reason thought that the 2V 5.4L was commonly fitted with the 4R100, though it may just be the wording in the manual that specifically talks about the 4R100 only being available behind the 5.4L....

My comparison wasn't being drawn toward the OP's point, but rather that of the person I responded to who had a 5.4L truck, which, if it has the 4R100 in it, has different "advice" in the manual for towing (I know mine does).
 
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