OVERDRIVE OR NOT

[spitts55]

I have a 2011 travel trailer 22ft and a 2003 expler 4.6 class three hitch with trailer tow do i use overdrive all the way to my destination or not .thanks

[gcloss]

I had a similar setup, but with a 2004 Mercury Mountaineer. I only pulled a large pop-up and only towed with the OD off.

From my experience with an almost identical SUV, you are near at or over the limits of the Explorer.

[mich800]

Terryallan wrote:
My manual says the trany will stay cooler wit OD locked out. For the same reason. The fluids circulate more, because there is higher RPM. I also get better MPG, and better performance with OD locked out. My engine is MUCH happier turning a little more RPM.

To the OP. I wouldn't worry too much. Your trany ain't gonna hold OD anyway.

I don't think it is an rpm thing. Many times the trans may shift into OD but cannot achieve lockup or goes in and out of lockup but stays in OD. This is when the heat builds.

[mich800]

nevadanick wrote:
I had a pickup with a 4.6 and my experiance is it will never shift into overdrive pulling something anyway, so i wouldnt worry about it.

I have experimented and this is generally true except downhill.

[Gdetrailer]

Reyhed writes “LOL, I don't even know where to begin, I'll take your advice and knowledge on this subject...... never! 2000 f350 has no otw trans cooler, just an external, there are more, that is just one example. We need facts not speculation.”

I would highly doubt that your F350 was not FACTORY equipped with radiator cooling of the transmission fluid…

And a very SIMPLE search for 2000 F350 radiator shows the same radiator is used for 6.8 V10 AND 7.3 Diesel AUTOMATICS. If you have side tanks radiator the transmission lines connect on the drivers side.

2000 F350 Radiator

Click the pix in that link and if you take a look at the BOTTOM of the radiator you WILL find TWO brass ports, those are where the transmission cooler lines connect.. If yours does not connect there or is no connections there then someone HAS put in a radiator which does not belong (like a radiator from a truck which had Manual transmission).

I CAN guarantee that my 2003 F250 with 5.4 DOES INDEED have BOTH radiator and external transmission cooler, same as my previous 97, my current 2006 and new 2013 F250s.

My 2003, I had the transmission oil cooler line spring a LEAK just 6 inches away from the point of entry to the radiator that I had to repair. PA winters are hard on steel lines. My 2003 and 2006 F250s have the oil cooler lines are at the BOTTOM of the radiator, one side is towards the drivers side of the radiator and the other line is near the passenger side of the radiator right beside the lower radiator hose.

Here is instructions for the OPs vehicle.. although a bit English challenged but you should be able to figure it out..

FORD EXPLORER RADIATOR REMOVAL INSTRUCTIONS

"Ford radiator Removal Instructions
1. Disconnect the battery cables utilizing a wrench. Then remove the battery from the vehicle.
2. Take away the battery tray using a wrench, ratchet and socket.
3. Place a big catch pan below the radiator and open the drain valve to empty the coolant from the radiator. Then shut the radiator drain valve.
4. Disconnect the upper radiator hose. Use a Phillips screwdriver or ratchet and socket to loosen the clamp, and then twist and pull the hose off the radiator fitting.
5. Disconnect the reservoir hose from the radiator. Use a pair of slip joint pliers to remove the clamp after which pull the hose off the radiator.
6. Place a small drain pan underneath, in the direction of the higher transmission cooler line, and detach the upper transmission cooler line from the radiator. Use a flare wrench. Then cover the line with a plastic bag to keep away from contamination of oil cooler system.
7. Unscrew the two A/C condenser mounting bolts, utilizing a ratchet and socket.
8. Jack up the entrance of your Ford automobile, utilizing a ground jack, and safely assist it on two jack stands.
9. Take away the radiator support brackets, using a ratchet and socket.
10. Disconnect the decrease radiator hose, using a Phillips screwdriver or ratchet and socket to loosen the clamp. Then twist and pull the hose off the radiator fitting.
11. Place the small drain pan underneath, within the course of the decrease transmission cooler line, and detach the decrease transmission cooler line from the radiator. Use a flare wrench. Then cowl the line with a plastic bag to avoid contamination of oil cooler system.
12. Unscrew the two A/C condenser-retaining bolts from the radiator, using the ratchet and socket. Move the A/C condenser to the aspect and safe it with a bit of wire, if necessary.
13. Detach the ability steering cooler from the radiator, if your particular Ford model is provided with it. Use a ratchet and socket.
14. Carry the radiator from the vehicle."


The transmission cooler lines are small steel lines and in the case of the OPs vehicle would be on the drivers side of the radiator. Shown in the pix in the link below, the lines connect at the two brass ports.

EXPLORER RADIATOR

Using the radiator to cool the transmission fluid is a very cheap way to cool the fluid, saves the additional cost in materials so you bet most manufacturers WILL take advantage and use it.

The use of the radiator for the cooler also has an additional side benefit for those who live in the cold north, it helps to WARM UP the transmission FASTER in the winter time. This is an important item since a warm transmission will shift better and results in LESS wear to the transmission.

There are however possible variations on this theme, some vehicles equipped with HD or towing packages may have an external cooler which is placed IN FRONT of the A/C condenser WHICH IS IN ADDITION TO THE RADIATOR COOLER.

Follow the MANUAL and you will be fine (after all it was written by the same folks who designed and built your vehicle so THEY SHOULD KNOW), as per manual if it shifts EXCESSIVELY then lockout OD otherwise occasional up shift/downshift is fine.

[Gdetrailer]

limbery wrote:
My TV has a tow mode switch which disables overdrive for pulling trailers...

Care to tell us what that vehicle is? I have never heard of such feature.

Fords Tow/Haul DOES NOT disable OD but it does change shift point strategy and provides automatic downhill braking.

I assume GM does the same, not sure about Rams though..

[limbery]

My TV has a tow mode switch which disables overdrive for pulling trailers...

[uzikaduzi]

i've always been told (and it seems the owner's manual confirms this) that you only need to lock out od when the tranny is shifting excessively to find the right gear... that being said i've never towed in od because i've never towed in flat areas... even a minor grade seems to force me to down shift. locking out od would likely only hurt your gas mileage (and that may not even be the case if you your running close to where the tranny would down shift but doesn't) if anything where as excessive shifting could cause the tranny to over heat

if you want to use od, try it out... you'll know pretty quickly if you're TV is shifting a lot. if you don't want to use it, it certianly wouldn't hurt anything to lock it out

[ryhed]

Gdetrailer wrote:

peirek wrote:

path1 wrote:
I want the fluids (transmission and coolant) to circulate faster than in overdrive mode.

This! It will make a difference in your Tranny fluid temps.

:R

Total B. S.tuff.

The fluids pumped around via transmission are NOT going to "circulate faster" whether in OD or not in OD.

What you MIGHT see though since the engine will be TURNING HIGHER RPMs is the engine COOLANT will get circulated faster to a certain extent.

The engine fan will also be running faster but at speed will not have much over all effect.

Folks tend to put WAY TO MUCH time and energy in worrying about engine coolant and transmission oil temps.

Folks, please understand the STANDARD configuration of modern day vehicles from the time automatic transmissions were invented the transmission fluid is plumbed into the radiator via a short loop internally in the radiator.

This loop is placed at the BOTTOM of the radiator tank where the engine coolant is the LOWEST temperature possible. This loop will keep the transmission fluid near engine coolant temps (that IS the way it is designed).

Additionally with vehicles which are factory setup for towing they will have a SECONDARY transmission cooler plumbed in AFTER the radiator loop.

99.9999% of the time this is plenty sufficient to keep the transmission temps well within the factory specs.

With that said, the OP should FOLLOW the FACTORY RECOMMENDATIONS OUTLINED IN THE MANUAL as to whether or not to lock out overdrive.

I myself HAVE NEVER locked out overdrive UNLESS the transmission continually "HUNTS" gears (down shift then up shift in a quick repeating pattern).

I towed with a 97 and 2003 truck with 4 speed automatic overdrives and I can only think of once or twice I locked out over drive and that was only for that particular grade.

Newer vehicles with Tow/haul mode is completely different, the T/H mode DOES NOT LOCK OUT OD.

I would say if the manual does not tell you to lockout OD while towing then try driving with OD and if transmission downshifts and upshifts too much (up/down quick pattern) then lock it out. The continual shifting is actually where damage can come from, not the fluid temps.

LOL, I don't even know where to begin, I'll take your advice and knowledge on this subject...... never! 2000 f350 has no otw trans cooler, just an external, there are more, that is just one example. We need facts not speculation.

[Nvr2loud]

Doug33 wrote:

Nvr2loud wrote:
I have a 2011 Sierra with the 5.3 and use the tow/haul button when towing my 30 foot trail cruiser. I have found that the Sierra rarely goes into 6th gear (second overdrive gear) when towing anyway. When very hilly it hunts from 4th to 5th (first overdrive gear)and I manually lock out 5th and 6th gears when this occurs. Once the terrain changes again, I put it back into D and let the transmission act as designed.

Back when I was towing with my 2001 Sierra, I kept 4th gear (overdrive) locked out since my tow/haul button stopped working anyway and the truck really struggled in 4th gear.

With my Acadia I lock-out 5th and 6th gear when hilly, and I allow 5th gear when flat, but 6th gear towing really increases my fuel consumption in that vehicle.

I always tow in tow mode

Me too.

[Doug33]

Nvr2loud wrote:
I have a 2011 Sierra with the 5.3 and use the tow/haul button when towing my 30 foot trail cruiser. I have found that the Sierra rarely goes into 6th gear (second overdrive gear) when towing anyway. When very hilly it hunts from 4th to 5th (first overdrive gear)and I manually lock out 5th and 6th gears when this occurs. Once the terrain changes again, I put it back into D and let the transmission act as designed.

Back when I was towing with my 2001 Sierra, I kept 4th gear (overdrive) locked out since my tow/haul button stopped working anyway and the truck really struggled in 4th gear.

With my Acadia I lock-out 5th and 6th gear when hilly, and I allow 5th gear when flat, but 6th gear towing really increases my fuel consumption in that vehicle.

I always tow in tow mode, since it is difficult to get the transmission into OD anyway. The tow mode keeps the tranny from hunting and making very big high-rev downshifts. It makes the engine run higher RPMs in general, but saves the tranny from shifts under stress and load.

[Nvr2loud]

I have a 2011 Sierra with the 5.3 and use the tow/haul button when towing my 30 foot trail cruiser. I have found that the Sierra rarely goes into 6th gear (second overdrive gear) when towing anyway. When very hilly it hunts from 4th to 5th (first overdrive gear)and I manually lock out 5th and 6th gears when this occurs. Once the terrain changes again, I put it back into D and let the transmission act as designed.

Back when I was towing with my 2001 Sierra, I kept 4th gear (overdrive) locked out since my tow/haul button stopped working anyway and the truck really struggled in 4th gear.

With my Acadia I lock-out 5th and 6th gear when hilly, and I allow 5th gear when flat, but 6th gear towing really increases my fuel consumption in that vehicle.

[nevadanick]

I had a pickup with a 4.6 and my experiance is it will never shift into overdrive pulling something anyway, so i wouldnt worry about it.

[ROBERTSUNRUS]

🙂 Hi, on somewhat level ground, I always tow with my overdrive on. My owner's manual says it's OK to. Just turned over 102,000 miles.

[time2roll]

Gdetrailer wrote:
Instead it states to turn OD off IF you are experiencing EXCESSIVE SHIFTING form OD to other gears.

And I can about guaranty OP will have excessive shifting in most conditions.
First or second time the transmission drops out of OD just lock it out. I think you will end up just locking it out every time with a 4.6L and less than 4.10 gear. Even if just the torque converter unlocks would prompt me to lock out OD.

BTW what is the RPM at 60mph OD on vs off?