towing with o.drive

[frederic.c01]

hi all
with my b250 dodge efi, I have three speed + od.On the motorway is it possible to draw with the o.drive when the road is punt.
thank's for yr concils.
fred

[Silvertwinkie]

If your vehicle has a tow/haul mode, perhaps, but if not, the answer most likley would be no, unless you had the engine/trans computer re-programmed to lock the torque converter at a lower RPM, but even then, on some engine/trans, it's still better to drive in 3rd. Even if you did have the PCM re-programmed to lock the TC sooner than later, the trans will still hunt on the hills, which could kill the trans if you are not careful.

Anyway you go, it's a good idea to have a good trans cooler and a trans temp gauge so you can monitor and manage the trans temps.

[jcanavera]

Check your vehicle's manual and see what it says. GM normally puts something in theirs relating to this. The manual for my half ton van said no, the one for my 3/4 ton van says yes. Two different transmissions, tow/haul on the 3/4 ton van plus external transmission oil cooler.

Jack

[nickcrowhurst]

Frederic, I tow with a Dodge Ram 2500 truck. The owners manual states that OD should not be used for towing. As I tow on the flat east coast of the USA, I used to experiment with OD when the roads were flat, with a careful eye on my transmission temperature gauge. I recently experimented with sticking to 3rd gear. The mileage went down from 13 mpg to 12 mpg. I found that the noise actually seemed to lessen as the speed in 3rd gear exceeded 60 mph. As a result of this experiment over several hundred miles, I have decided never to use OD when towing. I don't find the benefits of towing in OD (less noise, better fuel consumption) outweigh the risk of burning out the torque converter lock-up clutches. I normally tow on interstate highways at about 62 mph . I hope this helps. Nick.

[Lee Davis]

I have heard several different thoughts on this. One dealer says it's OK to use OD if the trans is not hunting up and down and the RPMs are high enough, another says use tow/haul all the time. I have a 2004 Dodge 2500 Diesel and finally decided if I could keep the RPM's up around 1900 + with my gear ratio (and I don't know what that is) it won't be working the transmission too hard because it is up on the torque and horsepower curve. I pull a 1986 34 foot Limited weighing about 10K lbs.

OD at about 65 mph is about 1900 RPM. I only use that when it is pretty flat (and not windy) and I get about 14mpg. I use tow haul when it is hilly and 55 is about max speed I run at, as I recall, about 2200 RPM. It is noiser and fuel mileage drops to about 11 mpg.

This comes with the disclaimer that I may not be doing right and eventually will pay for it, and your tow vehicle could require a different approach

[jcanavera]

Originally Posted by Lee Davis

This comes with the disclaimer that I may not be doing right and eventually will pay for it, and your tow vehicle could require a different approach

And that's why I recommend following the manual that comes with your tow vehicle. There are way too many of us experts out there who think they have it figured out.

I've towed trailers for 25 years, in the flatlands, Colorado, Ozarks, Smokies and many other places. I've never lost a transmission and I attribute that fact to following manufacturers towing recommendations (gear choices and load limitations), transmission oil coolers, and changing transmission fluids regularly. If you do this, and unless there are inherit defects within the transmission, your transmission will give you long and trouble free life.

Jack

[frederic.c01]

hi all
after the reading of your comments, I read again the handbook of the van.it has a switch to remove the od to thus draw a trailer. i think with the od less rpm less petrol.it is very expensive in France about 1 usd per liter.
fred

[BigAl]

I have found that the difference in fuel economy between overdrive and third gear when towing my trailer is almost 0%.
The engine doesn't have to work as hard per revolution in third gear and the transmission definitely doesn't down shift as often.
Bon chance.
Al

[frederic.c01]

thank you
it 's just by saving in fuel, if there is no difference between overdrive and third gear it is not necessary to take risks with the transmission.
55/60 mph it is a little slow on our motorway in France but it is the speed limit for the trucks,also we roll like them.
fred

[Rob30044]

When I am towing on flat terrain I use overdrive, otherwise I use tow/haul mode. Trailer weight, engine size and rear axle ratio all play an important part in towing.

Ben

[72 tradewind]

Don't do it! It will kill your transmission

[Mike Lewis]

Originally Posted by 72 tradewind

Don't do it! It will kill your transmission

That blank statement simply is not true!! Using overdrive to tow depends on the tow vehicle you're using and the load you're towing. READ YOUR MANUAL !!
pieman

[Rob30044]

Originally Posted by Mike Lewis

That blank statement simply is not true!! Using overdrive to tow depends on the tow vehicle you're using and the load you're towing. READ YOUR MANUAL !!
pieman

I agree. My tow vehicle is a 2001 Chevy Crew Cab, 4WD, 8.1 eng. 4:10 axle ratio. According to my owners manual I can tow a trailer with a maxium weight of 15,200 lbs. My 89 Excella GVWR is 8,300 lbs. I don't think that I will damage the 5 speed Allision transmission towing in overdrive on level terrain.

The owners manual states Tow/haul is most useful under the following conditions:

* When pulling a heavy trailer or a large or heavy load through rolling terrain.

* When pulling a heavy trailer or a large or heavy load in stop and go traffic.

* When pulling a heavy trailer or a large or heavy load in busy parking lots where improved low speed control of the vehicle is desired.

Ben

[65glbtrotter]

Originally Posted by Mike Lewis

That blank statement simply is not true!! Using overdrive to tow depends on the tow vehicle you're using and the load you're towing. READ YOUR MANUAL !!
pieman

I tow a '65 Globetrotter with my '05 GMC Sierra and most of the time I leave to OD on and my trans temp does not go up, the only time I turn it off is when I am going up step hills and it kicks down a gear!

[azflycaster]

Originally Posted by Mike Lewis

That blank statement simply is not true!! Using overdrive to tow depends on the tow vehicle you're using and the load you're towing. READ YOUR MANUAL !!
pieman

My TV manual says to turn off OD whille towing. I tow with OD off.

[markdoane]

Originally Posted by azflycaster

My TV manual says to turn off OD whille towing. I tow with OD off.

What vehicle?

[Silvertwinkie]

Originally Posted by Mike Lewis

That blank statement simply is not true!! Using overdrive to tow depends on the tow vehicle you're using and the load you're towing. READ YOUR MANUAL !!
pieman

I totally agree. That is a blanket statement that is not true in all cases.

In my case I did my homework and modded the PCM to lock the TC sooner than later and then monitored the trans for hunting. Installed trans cooling items and a trans gauge. I've towed several thousand trouble free miles in overdrive...my manual didn't say if it was safe or not. If your manual also doesn't say, or you don't have tow/haul mode, it's a safer bet to tow in 3rd unless you know what you are doing.

Any savings in gasoline towing in OD will clearly be offset by the cost of a transmission rebuild or replacement if you err on the wrong side!

[azflycaster]

Originally Posted by markdoane

What vehicle?

2003 Tundra 4X4

[SafeHarbor]

My Dodge diesel manual says to shift out of overdrive when pulling a heavy load, in hilly areas, or into strong crosswinds. It says that when the transmission shifts out of overdrive by itself, you should turn overdrive off to prevent excessive transmission wear or overheating and to provide better engine braking. Daimler Chrysler has monkeyed with this since then, taking away the OD lockout in the next few years and calling it a tow-haul mode with modified shitfting paramenters, and now it's back in the new 06 models. They have both the tow/haul mode AND the OD lockout.

I know that I towed my Excella from Michigan with a 93 Dakota using overdrive everywhere that was flat, and third everywhere it went up. At the October forum rally in Ft. Desoto, I pulled it over some gently rocking hills on OD crossing FL. overlander63 innocently asked me, "So, do you tow this in overdrive?" Then he said "Hmmm."

That's a bit unnerving hearing something like that from a person who knows more about my truck than I do. Although I had no problems at all getting it home, two weeks later I traded the Dakota in for the 03 Ram. And, yes, I will tow in overdrive when it's flat.

Lamar

[overlander63]

Originally Posted by SafeHarbor

I know that I towed my Excella from Michigan with a 93 Dakota using overdrive everywhere that was flat, and third everywhere it went up. At the October forum rally in Ft. Desoto, I pulled it over some gently rocking hills on OD crossing FL. overlander63 innocently asked me, "So, do you tow this in overdrive?" Then he said "Hmmm."

That's a bit unnerving hearing something like that from a person who knows more about my truck than I do. Although I had no problems at all getting it home, two weeks later I traded the Dakota in for the 03 Ram. And, yes, I will tow in overdrive when it's flat.

Lamar

I cooked the 518 Overdrive transmission in my Dakota while on vacation towing our Argosy. The torque converter started shuddering when it engaged, then finally failed completely just after arriving back home. $1800 later, I read my owner's manual, and it very specifically stated not ever to tow anything in overdrive. This was a virtual identical twin to Lamar's Dakota. The only real difference was the color.
But again, this is what it said in my owner's manual, and it seems almost every tow vehicle out there makes different recommendations on the subject. The best thing I can suggest is to do what your owner's manual tells you. If for some reason you don't have an owner's manual, you can order one from the manufacturer.