Do you turn off the overdrive?

[Mtelkman]

Wasn't the OP question about overdrive? I thought tow/haul and overdrive were different things.

[steelpony5555]

Talking to a very knowledgeable Dodge tech, he advised if you are towing over 5k lbs then tow haul should be on and lock the tranny in 5th. This is for newer trucks and depends on the RPM's and your rear gears. On my old truck with 4:10 gears and 4 speed it would just drone along and rarely shift. Fast forward to 2010 truck and any mole hill would cause the truck to down shift. But now I have 3.73 gears and a 6 speed tranny. So now I tow in 5th and it drones along again. But the RPM's have to be up around 1800 to keep it from gear hunting. He also advised me that if driving in a city I should manually shift the truck to a gear low enough to keep my RPM's up and keep it from lugging...

[18CrewDually]

This is a vehicle specific question. My 05 F350 is nothing like a Jeep Liberty.
But to answer your question, no I do not take it out of overdrive but I do put it in Tow mode. Higher shifts to keep the rpms in the torque band, and engine braking are two benefits for me.
Consult your owner's manual, follow the recommendations, from your observations do what works for you.

[B and B]

Many have said it already. Read manual, based upon an opened ended statement that is all that can be said. If you are towing through the Laurenitian's with a Jeep Liberty you might very well not have enough TV for the back roads. I would be careful with trying to over do it, the Liberty is a passenger car.

[JoBu]

I'm towing a Rockwood Roo 21DK (approx. 5000 GVW) with a Chevy Avalanche 5.3 2WD. I am typically in "tow mode" with overdrive off unless I'm on a very flat portion of highway/road. Even overpasses tax my Chevy (then again, I'm very new to this and perhaps bit hyper-sensitive). I'm still getting used to all the pops/clicks from the WDH. As other posters have stated, I'd err on the side of caution and not over do it.

Cheers,

Joe

[RSchleder]

I always push the "tow/haul" function whenever I tow my trailer! And why not as it put's less stress on the drive train. If I can't afford a bit more gas, maybe I shouldn't own an RV!

[aceinspp]

Originally Posted by fmc

I do not use the tow mode most of the time. I do use it if we are in the mountains or another very hilly or steep grade area. I also use cruise control to maintain a constant 62 MPH which seems to give us the best fuel economy.

X 2 and go by what manual recommends. Later RJD

[MKClark]

I just put it in tow mode and let the computers do their thing.
2014 Chevy. 1/2 ton, 5.3, 3.42 rear. Pulling 7,700 lb. Windjammer.
Set curse at 65 mph. Pulls great on flat lands of Texas. Still have plenty of power
to pass big rigs. Keep close track of trans temp.
_____________
MK Clark
2014 Silverado
23015 2819VS Windjammer

[Filthy Beast]

My book tells me the max torque is at 1800 rpm and towing at 65 mph or slightly under runs the engine right around 1800 rpm while in 6th gear with tow/haul used whenever towing.

[Brother Les]

Originally Posted by Filthy Beast

My book tells me the max torque is at 1800 rpm and towing at 65 mph or slightly under runs the engine right around 1800 rpm while in 6th gear with tow/haul used whenever towing.

Every truck when pulling has it's 'sweet spot', this may be yours. I used to drive hundreds of miles at 70mph and my RPMs would be around 2100. (Diesel)

(I don't drive 70mph much any more, 65mph is just fine all the way around at the slower speed. 1900RPMs)

[Cowracer]

Just for clarification...

Overdrive in not some mysterious component. It simply means a taller than 1:1 gear ratio.

The venerable Ford C4 transmission has 3 speeds or gears. the gear ratios for the 3 speeds are: First is 2.46:1. This means the input shaft turns 2.46 turns for each turn of the output shaft. Second is 1.46:1 and third is 1:1 or each turn of the input shaft equals one turn of the output shaft. Gears 1 and 2 are "underdriven" as the output shaft turns slower (at any given speed) than the input shaft. Third is considerd a "direct drive" as the shaft speeds are equal.

The Ford E4OD is a 4-speed transmission, with gear ratios of:

1st=2.71
2nd=1.54
3rd=1.00
4th=.71

Like the C4, gears 1 and 2 are 'underdriven' and gear 3 is 'direct'. But! There is a 4th gear who's ratio is 0.71:1 This means the input shaft turns only .71 of a turn for each turn of the output shaft. It spins slower than the output shaft so it is called "overdriven".

This is all that overdrive is. Its just indicates a final gear that is overdriven. It's not some sort of additional component that kicks in and out inside the transmission. Locking out "overdrive" simply means that you are not allowing your transmission to shift into its highest gear. It would be like driving your old C4 and keeping the selector in 2.

There is nothing to "burn out" by running in overdrive. What can happen (and did in early OD transmissions) is that you run the input shaft so slow that you cannot get adequate oil flow for proper cooling. The oil pump is run off the input shaft, and if you are towing a heavy load and not moving enough oil, temps can rise dramatically.

Modern transmissions are perfectly happy towing up to the max weight in OD. However, to aid things, you can select OD off to keep the revs up and the oil flowing. But remember, all that button does is prevent the trans from shifting into its highest gear.

Tim

[Mr. Dan]

Originally Posted by Wumba

When climbing into hilly or mountainous terrain I use tow mode or drop into the Allison transmission 6 speed. 2006 Chevy 2500HD diesel.

Wumba, what do you mean when you say "I... drop into the Allison transmission 6 speed"? You're using the Allison transmission 6 speed all the time, right?

[MtnGuy]

Originally Posted by Cowracer

Just for clarification...

Overdrive in not some mysterious component. It simply means a taller than 1:1 gear ratio.

The venerable Ford C4 transmission has 3 speeds or gears. the gear ratios for the 3 speeds are: First is 2.46:1. This means the input shaft turns 2.46 turns for each turn of the output shaft. Second is 1.46:1 and third is 1:1 or each turn of the input shaft equals one turn of the output shaft. Gears 1 and 2 are "underdriven" as the output shaft turns slower (at any given speed) than the input shaft. Third is considerd a "direct drive" as the shaft speeds are equal.

The Ford E4OD is a 4-speed transmission, with gear ratios of:

1st=2.71
2nd=1.54
3rd=1.00
4th=.71

Like the C4, gears 1 and 2 are 'underdriven' and gear 3 is 'direct'. But! There is a 4th gear who's ratio is 0.71:1 This means the input shaft turns only .71 of a turn for each turn of the output shaft. It spins slower than the output shaft so it is called "overdriven".

This is all that overdrive is. Its just indicates a final gear that is overdriven. It's not some sort of additional component that kicks in and out inside the transmission. Locking out "overdrive" simply means that you are not allowing your transmission to shift into its highest gear. It would be like driving your old C4 and keeping the selector in 2.

There is nothing to "burn out" by running in overdrive. What can happen (and did in early OD transmissions) is that you run the input shaft so slow that you cannot get adequate oil flow for proper cooling. The oil pump is run off the input shaft, and if you are towing a heavy load and not moving enough oil, temps can rise dramatically.

Modern transmissions are perfectly happy towing up to the max weight in OD. However, to aid things, you can select OD off to keep the revs up and the oil flowing. But remember, all that button does is prevent the trans from shifting into its highest gear.

Tim

Ecellent explanation, Tim !!

The ratios you show for the Ford E4OD are very close to what shows on my Scan Gauge. I think they are 2.85 for 1st, 1.55 for 2nd, .99 for 3rd, and .69 for OD. With the Scan Gauge, i also monitor my transmission temperature, which stays in the 160 to 180 range while towing in OD on a hot day. I only turn off OD when in hilly areas, and the tranny would be shifting to 3rd. I do not usually run the cruise control, and then only in 3rd.

My owners manual reads something like: "Turn off OD when the transmission frequently shifts to a lower gear".