The Boating Forum - OD on or OFF

Quik question Ford Expidetion 5.4 V8 here better to tow with OD on or OFF.
23ft about 5500lbs boat that is.

or does towing with OD off heat up the trans.

need to know just got it O4 model
last truck trans. went out last summer dealer put reman. in but did not act rignt. 01 model 5.4

no bashing please serious question
I will play with you later

I used to have the Expedition with the same engine and my previous boat was almost the same size (I had a 22 that weighted about 4200 lbs dry). I always towed with the OD off. If you tow with it on, I'd assume you'll wreck that transmission in short order. I could always tell right away when I forgot to turn the OD off, it would constantly be shifting looking for different gears.

I just read some information recently...a post in another forum and dont know its accuracy...that the transmission will actually run cooler OUT of overdrive when towing because it tends to "hunt" back and forth from 4th to 3rd to 4th, etc. That was NOT on a Ford, but it sure makes sense that it would apply to all. I tow with OD off. I now have a Toyota Tundra but had to replace two Ford tranmissions and don't want to start that on the Tundra.

I would think that if your transmission is "hunting" it would be better to turn it off. If you are on level ground and its running smoothly leave it on.

Best to turn it off. The minor savings in fuel is not worth the potential damage to the transmission that you might incur. Thats my plan and I'm stickin to it.

ron

Always go with OD when in doubt. If you are on flat roads and you can maintain speed easily, then you can go with OD, but at the first sign of gear hunting - get it out of OD.. ;)

Dumb question on my part, but if you are towing with the OD, can you push your tow/haul button to take it out of OD while at speed? It's an 04 Durango with V8.

gordo35-
Yes you can push the OD button while towing. If the truck is actually in OD gear, best to accelerate, get trans to kick out of OD then press the button. At least that's how I do it with my Durango if I forget to take it out first. Just "feels" better to kick it out before pressing the button. My Durango has the Full Time 4X4 option too. I tow in 4X4 mode. Power distributed to all four wheels feels better than just the rear. Also nice once at the ramp to be in 4X4. NOTE Do not tow in 4X4 if you do not have the Full Time All Wheel Drive option. You'll blow your front axle using standard 4X4.

No Overdrive while towing, some transmissions are more delicate than others. So with some you can get away with it, others you can't.
Transmission will run hotter while in OD, heat kills transmissions!

OFF

OD is a no no when towing at highway speeds.

Overdrive is a 5th gear on my car. When in OD your gear ratio is spread out more over 5 gears.

Overdrive is for speeds above 50 according to my manual. On my car, When you activate od at 70 mph my rpms drop by about 1200.

Now if you are trailering and driving on the highway in that 50+ mph zone your are going to be working the transmission very hard because it is going to shift down to 4th and back into 5th frequently depending on how much gas you give it. By turning off the od you are giving a little wider bandwidth (for lack of better word) to each gear. Remember, when towing you have to give the car significantly more gas to maintain or upgrade speed.

I hope this helps.

LooneyTunes
Dave

We have two SUV's, an Envoy and a Ford Explorer Sport. Both of the vehicles owners manuals say do not tow in OD...........

One of the reasons is that if you leave it in 3rd, the torque converter can stay locked up which really cuts down on heating the trans fluid. If you run in od not only will it be shifting back n forth from 4th to 3rd but the converter clutch will be locking and unlocking every time you hit the gas and that heats up the fluid quite a lot. I have also heard that on some trans the OD clutches are not strong enough to pull loads, they are light duty for light loads. The other advantage of no OD is you get much better engine braking, which is a help with a trailer, even with good trailer brakes.

LouC is correct.

Ford recommends to tow with the OD......off.
The way the tranny is set up, you will cook it, running with it on.
Also there is only a 500 RPM drop on mine, and I am not lugging the tranny on hills. :)

off

cclancer - 4/17/2005 11:38 AM

LouC is correct.

Ford recommends to tow with the OD......off.
The way the tranny is set up, you will cook it, running with it on.
Also there is only a 500 RPM drop on mine, and I am not lugging the tranny on hills. :)

Interesting comment as my 2002 F250 SD manual does not address this question............... so I called Ford and asked. They said as long as the trans is not 'hunting' I can go with OD on. If it starts to hunt then turn OD off. I tow about 6,000 pounds. On flat land (VA Tidewter area to Oregon inlet) I can tow with OD on. It's a 5.4L w/3.73 LS rear and the 4R100 trans. I also have a trans temperature guage which really helps a lot when determining whether in OD or out.

I'm confused.

When I had a Ford E350 the manual said turn OD off when towing.

Now I have a 99 Suburban and the manual says tow in OD.

What gives?

Turn the Overdrive OFF! By running with the torque converter locked up and the engine running with lighter torque load and slightly higher RPM, the tranny can stay cooler. Heat kills trans fluid.

If you don't already have an auxillary trans cooler and heavy duty fan clutch, consider adding them. Heat kills tranny's, and anything you can do to take off the heat while cruising will extend the life of the tranny.

Another consideration - cold kills. Yes that's right - cold loading can also reduce the life of an automatic tranny. Let that puppy idle and warm up a bit before towing or pulling the boat up a ramp.

Most modern auto tranny's will not lock in the torque converter until the engine temperature reaches a predetermined point. On my '95 Ram, that point is 135 F. Tranny fluid is very very thin oil, and as such, bushing and bearing clearances are somewhat critical. Too cold or too hot and those clearances are screwy.

So, don't load her up too much when she is cold, and turn the OD off when towing. Add additional cooling, have the filter changed regularly (it's amazing what stuff you will find in the trans pan) and consider getting a fluid flush once or twice in her lifetime. Do all that stuff and she won't let you down!

For what it's worth, my Dodge (which has a reputation for a notoriously poor tranny) has 172K miles on her and I have never had any tranny issues :thumbsup:

As long as the tranny isn't hunting its ok but just turn it off before you go up a hill. Check out http://www.ford-trucks.com/forums/index.php? for more questions on towing ang your truck.

----
86' 236 Mako CC w/Penta TAMD 40A Diesel Inboard

I concur with the comments to keep out of overdrive. However, it is not only a consideration of saving the transmission, it is also a matter of what is best for the engine. If the transmission is locked in overdrive, the engine is probably running in the low 2000's RPM at speeds of 60 to 70 mph. Since the engine has significantly greater stress while towing, it is best for the engine to run closer to peak torque RPMs. Most gas engines will acheive peak torque somewhere between 3000 and 4500 RPM. When running one gear below overdrive, engine RPM will typically be around 3000 RPM at speeds of 60 to 70 mph which is where it should run. Keep RPM's up to save both transmission and engine.

ReelWork - 4/15/2005 2:53 PM

Always go with OD when in doubt. If you are on flat roads and you can maintain speed easily, then you can go with OD, but at the first sign of gear hunting - get it out of OD.. ;)

I guess I left out the key word "OFF" in the first part.. :roll :trout:

As in "Always go with OD OFF... "

I use a Nissan Xterra as my tow vehicle which has an OEM transmission cooler. I use the OD off for low speed towing and flip OD on when on level ground or downhill and the engine/transmission then flip the OD off when I feel the engine looking for more power. Its a compromise, but so far it seems to keep me running smoothly on the highway.