Turning overdrive off on flat highway important?

JasonBo

Petty Officer 2nd Class
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Jul 18, 2010
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103
I tow a 20ft stratos with a V6 ford explorer sport trac. If im not doing hills but just flat terrain how vital is O/D off.
 

ThePartsMan

Petty Officer 3rd Class
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Jul 20, 2010
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Re: Turning overdrive off on flat highway important?

Your transmission will last longer and I would bet that you get better mileage towing the boat.
 

Titanium48

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Apr 24, 2008
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Re: Turning overdrive off on flat highway important?

If tranny can't decide what gear it wants to be in or the torque converter randomly unlocks without shifting (rpm increases by 200-300 with no increase in speed), turn off OD. If there's no shifting and the tach and speedo needles are always in synch you should be fine in OD.
 

bruceb58

Supreme Mariner
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Re: Turning overdrive off on flat highway important?

Also..read your owners manual. It will tell you what is recommended.
 

reelfishin

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Mar 19, 2007
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Re: Turning overdrive off on flat highway important?

If tranny can't decide what gear it wants to be in or the torque converter randomly unlocks without shifting (rpm increases by 200-300 with no increase in speed), turn off OD. If there's no shifting and the tach and speedo needles are always in synch you should be fine in OD.

The above post pretty much says it, but things like head wind, increased grade, and weight all play a role in what works. With that trans, I'd be darn sure you know when its fully in OD and locked up, so you know when its hunting or shifting too often.
You also want to keep an eye on your temperature gauge too. If it's running higher, then so is the trans. Towing a 20' boat with an Explorer, you definitely want a larger aftermarket transmission cooler on there.
 

Philster

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Sep 15, 2009
Messages
3,344
Re: Turning overdrive off on flat highway important?

Overdrive creates a lot of heat. Heat kills transmissions. The trans isn't turning fast enough to cool itself in O/D when under heavy load. That is where the 'over' part comes from. You are at a ratio beyone 1:1 (so to speak), so you don't have the circulation to cool things. Meanwhile, there is heat building, because you have more than normal load. O/D is fine when the load is normal... the trans will cool itself. Towing? Not so much.

Turn off O/D if that is what is recommended. Some transmissions are designed to tow in O/D, because they have that in mind when cooling is considered during design.
 

robert graham

Admiral
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Apr 16, 2009
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6,908
Re: Turning overdrive off on flat highway important?

If you do much towing then invest in a transmission cooler, they're cheap and easy to install and will help keep your transmission fluid cooler.
 

krakatoa

Senior Chief Petty Officer
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Aug 8, 2008
Messages
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Re: Turning overdrive off on flat highway important?

I tow a 19 footer bowrider with my Jeep Grand Cherokee V6 2004 4x2 always WITH O/D Off. I feel my truck towing in "relax mode" NO PROBLEM!!!
 

geeco1

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Re: Turning overdrive off on flat highway important?

I had an older Ford Ranger pick-up (I think it was a mid 80's), anyway, I picked up a refridgerator from my parents house and was traveling about 150 miles, mostly highway. The fridge, was standing upright. My wife was following behind me (she runs fast:D) .... in our van. about 40 miles into our trip, she calls me on my cell and says that there is a lot of smoke coming from under the truck. I stop to investigate but don't see anything unusual (other than a lot of smoke:confused:). Long story short, I had the truck in overdrive. Turning the overdrive off, I had no more problems. The fridge had enough wind resistance to strain and overheat the transmission. It had spilled transmission fluid out the vent and onto the exhaust causing the smoke. Once I turned overdrive off and allowed it to cool some, no more issues.
 

bruceb58

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Re: Turning overdrive off on flat highway important?

You are at a ratio beyone 1:1 (so to speak), so you don't have the circulation to cool things. Meanwhile, there is heat building, because you have more than normal.
You don't know that. The pump in the torque converter may be designed already to have high output while still at low RPMs. Depends on the vehicle and that is why the owners manual will tell you. For example GM 1/2T trucks up until the mid 90s couldn't tow in overdrive. The transmission was redesigned later in the 90s so you could.
 

JasonBo

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Re: Turning overdrive off on flat highway important?

Thanks all for your replys. I guess the whole reason for this is a trip that nnormally takes less then aquarter tank of gas on a flat surface is taking me 1/2 or more with the over drive off. I just see my mileage disappear with it off. My boat ways roughly 1600 pounds and my towing cap is around 4k with the towbar so im under weight towing. I know if i was doing hills and steep grade its a must. Im planning a trip to south padre and if any of you ever driven it there is barley a speed bump of a hill between san antonio and there. It would be nice not having to stop for fuel every 5 mins.
 

gonefishie

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Jul 28, 2004
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2,624
Re: Turning overdrive off on flat highway important?

Are you sure your 20ft Stratos weights 1600 lbs? you maybe right but it seems light. My rig is lighter then your, not much, I had a Blazer with a Vortex V6. In OD, it hunted for gears whenever there is a slight change in grade, speed or wind. The faster the speed the worse the problem. It was a PITA when it comes to acceleration too. All was well with OD off but it sucked gas like no tomorrow, luckily gas wasn't expensive yet. I switched up to a Tundra with V8, tranny cooler and all. I tow in OD on flat grade all the time doing 70mph with no problem. The different in gas comsumption is not as drastic as the V6 though.
 

TyeeMan

Master Chief Petty Officer
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Feb 27, 2006
Messages
849
Re: Turning overdrive off on flat highway important?

Your Stratos is probably 1600 lbs dry, no gas, no batteries, no gear and deffinately no outboard. Also don't forget the weight of the trailer and wind resistance of the whole rig. I bet your over 2500 for the whole rig. Do yourself a favor and get a travel cover it'll make all the difference in the world towing.
 

geeco1

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Messages
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Re: Turning overdrive off on flat highway important?

You don't know that. The pump in the torque converter may be designed already to have high output while still at low RPMs. Depends on the vehicle and that is why the owners manual will tell you. For example GM 1/2T trucks up until the mid 90s couldn't tow in overdrive. The transmission was redesigned later in the 90s so you could.

I had a Chevy S-10 (several years ago) with a stick shift. I called GM and they told me that the truck was not made for towing??
 

642mx

Lieutenant Commander
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Apr 19, 2008
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1,588
Re: Turning overdrive off on flat highway important?

Thanks all for your replys. I guess the whole reason for this is a trip that nnormally takes less then aquarter tank of gas on a flat surface is taking me 1/2 or more with the over drive off. I just see my mileage disappear with it off. My boat ways roughly 1600 pounds and my towing cap is around 4k with the towbar so im under weight towing. I know if i was doing hills and steep grade its a must. Im planning a trip to south padre and if any of you ever driven it there is barley a speed bump of a hill between san antonio and there. It would be nice not having to stop for fuel every 5 mins.

As a former Ford tech... I can tell you that your wallet will become much lighter if you choose to tow with the over-drive on.
 

DonHof

Petty Officer 1st Class
Joined
Oct 19, 2009
Messages
318
Re: Turning overdrive off on flat highway important?

I have a 05 Ford Escape, the owners manual said nothing about turning O/D off
when towing.
 

ufm82

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Jul 29, 2003
Messages
827
Re: Turning overdrive off on flat highway important?

I drive a 2001 F150 Super Crew with the 5.4L engine and have towed a boat with it since new. Weights have gradually increased as my boat budget has increased and my current rig weighs in around 3,500 lbs or so. I have ALWAYS towed in O/D. In fact, I won't tow with the O/D locked out because the engine runs at 600-700 rpms higher in 3rd than in O/D and my mileage drops off dramatically. With 124,000 miles on it at this point I can honestly say that I have never had an issue. Granted, I service the tranny every 40,000 miles or so but even then the fluid is darker but definitely not burnt. I don't see any change in engine temp when towing either and I do watch my gauges very closely. I have towed from Ohio up to Canada and down to Florida multiple times a year. I can say that if there was ever a reason to lock out the O/D it would be going through the Jellico section of I-75 and I don't even kick it off then. I let the tranny downshift when needed and do use engine braking to save on the brakes but otherwise it's O/D all the way. While some vehicles may benefit from towing with O/D locked out, I don't see it in my vehicle. Tow package factory works just fine. And I'll shock you all with another fact that I'm sure I'll get flamed for. At 124,000, I still have original plugs, original coils, original coolant and original components on my truck. (That'll curse me now I'm sure.) Apart from oil changes, filters and brakes, I've had to do nothing other than a rear U-joint. That's on a truck that does pretty much nothing else anymore but tow my boat. It runs great, 17mpg unloaded and 12 with the boat.

UFM82
 
Joined
Jul 11, 2010
Messages
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Re: Turning overdrive off on flat highway important?

I cant believe there are vehicles built in the last 20 years with overdrive's! get a manual
 

sethjon

Senior Chief Petty Officer
Joined
Jun 8, 2010
Messages
692
Re: Turning overdrive off on flat highway important?

On a flat road why would you turn OD off? You get better gas mileage on and its no strain until you go upgrade.
 

Philster

Captain
Joined
Sep 15, 2009
Messages
3,344
Re: Turning overdrive off on flat highway important?

You don't know that. The pump in the torque converter may be designed already to have high output while still at low RPMs. Depends on the vehicle and that is why the owners manual will tell you. For example GM 1/2T trucks up until the mid 90s couldn't tow in overdrive. The transmission was redesigned later in the 90s so you could.

You took the time to completely ignore the part where I explain that some trucks are designed to tow in O/D AND to go by the manual. :mad:

Here is my post AGAIN:

Overdrive creates a lot of heat. Heat kills transmissions. The trans isn't turning fast enough to cool itself in O/D when under heavy load. That is where the 'over' part comes from. You are at a ratio beyone 1:1 (so to speak), so you don't have the circulation to cool things. Meanwhile, there is heat building, because you have more than normal load. O/D is fine when the load is normal... the trans will cool itself. Towing? Not so much.

Turn off O/D if that is what is recommended. Some transmissions are designed to tow in O/D, because they have that in mind when cooling is considered during design.
 
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