Do I tow with O/D off ?

[Captdru]

I just bought a 2001 Ford F 350 powerstroke 7.3. It is my first diesel. Truck is completley stock. I will be towing a 11000# boat from FL to OH. My question is should I tow with OD off or on? Rpms really jump up at 65-70 mph but I hear towing a heavy load in OD will burn up tranny. I need a pros advice.

[GEARJAMMER]

Originally Posted by Captdru

I just bought a 2001 Ford F 350 powerstroke 7.3. It is my first diesel. Truck is completely stock. I will be towing a 11000# boat from FL to OH. My question is should I tow with OD off or on? Rpms really jump up at 65-70 mph but I hear towing a heavy load in OD will burn up tranny. I need a pros advice.

Welcome to the site. Now for your question. Only you can answer it. It's perfectly OK to tow in O/D if your transmission is not hunting for gears. Translation = Frequently shifting up and down. I'm not an expert but I did own an 01, so I know the truck. I hate to admit it, but I sometimes towed grossing over 20,000 lbs. And this was done in O/D on flat ground.

Shawn

[JimmyDee]

If I'm on the free way I am always in OD. The only time I take it out is if I'm on a 2 lane road with rolling hills and am limited to about 50 mph. I find it runs easier up and down the hills at 50 mph better without the OD.
Your engine pulls like gang busters at 1600-2000 rpm and will do that all day long.
Jim

[knoweigh]

your best bet for tranny control is...........YOU

When I'm towing, I"m constantly watching gauges & listening to what the system is doing and actively doing my best to anticipate what's needed for that......"hill ahead".
Heck, even in town on flat ground running empty I sometimes take it out of overdrive as I don't want it hitting overdrive just 100ft before I need to slow down again for next light.
However, if you're the type that doesn't want to be that involved with the rig over a trip, and would prefer to blast the tunes, roll down the window and not concentrate that hard except enough to steer the vehicle, then OD off is the ticket for you.
So.....................again, your best bet is,...use your judgment. Become one with your rig and you'll be fine. I tow 12klbs through the mountains and am confident with it. I think I would even tackle 15klbs although I think that would be getting near past what I could ask from my truck even as confident/good as driver as I am.

best of luck

[SmokeyWren]

Originally Posted by Captdru

Rpms really jump up at 65-70 mph but I hear towing a heavy load in OD will burn up tranny.

You heard wrong. What will burn up your 4R100 tranny is allowing it to get too hot. And getting too hot is almost always caused by towing heavy at less than 37 MPH. Such as backing a trailer up a steep grade. Or towing us a slow crooked mountain trail where you can't maintain over 40 MPH.

The basic rule is to let the truck decide which gear it needs. If it needs to downshift out of OD, it will. If it doesn't need to downshift, it won't.

But there are two exceptions.

When coming down the mountain with a heavy trailer pushing on you, kill the OD until you get off the mountain.

And when in hills or climbing a mountain where the tranny often downshifts and upshifts, then kill the OD until you get out of the ups and downs.

My rule is when I see a grade ahead that I know will cause a downshift out of OD, I'll kill the cruise, slow down to the speed I want to climb the grade, then manually kill the OD before the computer does it for me. (That prevents the hard jerk if the computer downshifts at my normal 62 MPH.) Then I set the cruise on 55 or 60 MPH and take the mountain. My rig will tow my 8,000 pound 5er up any interstate mountain pass at 55 to 60 MPH without overheating anything. Depending on grade, I can usually cruise at 60 MPH with exhaust gas temp (EGT) of about 1,200º. Only on the steepest interstate grades will I have to back out a hair to keep from exceeding 1,250º EGT.

If you are spending lots of diesel towing at 70 MPH, with stock tires and calibrated speedometer that's about 2,600 RPM in direct drive. You could tow all day at 2,600 RPM and not hurt a thing except your wallet for a lot more diesel.

With mine, grossing 16k with a mid-profile 5er, at 62 MPH and 1,800 RPM, I get over 12 MPG. At 66 MPH and 1,900 RPM I get about 11 MPG. At 70 and 2,000 RPM I get less than 10. And at the normal speed of 73 MPH I get less than 9. So I usually tow at 62 MPH.

I tried one experiment. I towed my trailer about 350 miles at 62 MPH (over 2,300 RPM) with OD killed. I got about 9 MPG. Then I came back the same road with a headwind and gained 1,500 feet altutude, but using OD at 62 MPH, and I got over 12 MPG. So I definitely tow in overdrive except in the rare case of going up or down a mountain pass, or crossing the Texas Hill Country northwest of Austin.

[1/2tired]

If you check th eOwners Manual, it will tell you to tow with the Overdrive OFF... Like other owners though, I did pull a 7000 lb trailer over relatively flat terrain with the O/D still on. You are going to have to be the judge of how hard your transmission is working with a stock '01, so if it is hunting, back out of the cruise and take it out of O/D... Hope the trip goes well for you!

[SmokeyWren]

Originally Posted by 1/2tired

If you check th eOwners Manual, it will tell you to tow with the Overdrive OFF...

No, it doesn't. In fact, your 2008 doesn't even have a button to turn the overdrive off. And neither does the 6.0L with TorqShift tranny. The TorqShift tranny does have a tow/haul mode you should shift into when towing up or down steep grades, but it does not turn off the overdrive. Here's what the 2003 Owner's Guide says about towing with the TorqShift tranny:

Driving while you tow
When towing a trailer:
•...
• If your vehicle is equipped with a 5–speed automatic
transmission: To eliminate excessive transmission shifting, activate
the Tow/Haul feature. This will also assist in transmission cooling. ...

That's it. Not a peep about turning off the overdrive.

The '99-'03 7.3L does have an overdrive-off button, but the 7.3L Owner's Guide says only:

"Use a lower gear when towing up or down steep hills. This will eliminate excesssive downshifting and upshifting for optimum fuel economy and transmission cooling."

And in another place not associated with towing, it says:

"Automatic transmissions may shift frequently while driving up steep grades. Eliminate frequent shifting by shifting out of overdrive into a lower gear."

If you'll notice, that's basically what I posted near the beginning of this thread.

[Stretch56]

I tow a 13000lb 5er. Usually always OD off. Unless flat with a tail wind. Seems to never happen when I'm towing. I like to sit and drive, OD off the truck will cruise up and down with no down shifting. EGT's stay alot lower with the increased RPM's. I'am one that keeps the speed down, about 57, helps save the fuel.

[SmokeyWren]

Originally Posted by Stretch56

I'am one that keeps the speed down, about 57, helps save the fuel.

But you're wasting fuel when towing with the OD turned off.

A coupla years ago I did a test. 8,000 pound 5er trailer plus 2,500 pound tag trailer, cruise control set at 62 MPH (1,800 RPM in OD, 2,350 RPM with OD locked out), calibrated speedo. Filled with fuel until liquid diesel at the cap. Towed 350 miles to Dallas going downhill with the wind behind me and with OD locked out. Filled to the cap again. Less than 10 MPG.

Towed 350 miles back home, up hill and with a headwind, same load and same 62 MPH, but used the overdrive everywhere except climbing Ranger Hill. Filled to the cap again to be certain my MPG calculations were good. Over 12 MPG.

So at least on that trip I got 20 percent better MPG using overdrive everywhere I could.

[Captdru]

Thanks for all the good info. Looks like I should be ok towing in OD except in WV. Now I just have to get oversize load permits. That otta be fun.

[kbroadnax]

OD on unless it starts hunting. If you do not have one install a transmission temp gauge. One that gives you actual degrees of temp. They are relatively easy to install and will give you a good idea of how your trans temps are doing. Gauge is most important.

[BlueMuleTrucking]

O/D on the highway towing, otherwise its off around tow loaded or empty.

[TonkaThunder]

I pulled 10k lbs from wisconsin to phoenix in overdrive in my "old" truck in my signiture, and except for goin up and down the mountains I was in overdrive and she never complained. Hell coming down some of those tight cornered passes I dropped her down into second to save on the brakes!!!

[knoweigh]

Originally Posted by Stretch56

I tow a 13000lb 5er. Usually always OD off. Unless flat with a tail wind. Seems to never happen when I'm towing. I like to sit and drive, OD off the truck will cruise up and down with no down shifting. EGT's stay alot lower with the increased RPM's. I'am one that keeps the speed down, about 57, helps save the fuel.

uh;..yeah I would say if you weren't planning on reaching at least 62mph, then yes, OD off would about be the only way to go with a heavy load; however, I think most people cruise at a much higher rate of speed. Personally I don't have the patience for 57mph...so hats off to you for that
I'm no speed deamon (although I'm known to get my 19k gross rig flying downhill at over 80mph quite often).
My outfit likes to cruise on flat ground at 70mph real nice. OD locked up and tons of torque right there at 2k rpms and egts stay in check for decent MPG.

[LeRoy]

It depends on the speeds I can go bet generally I tow in OD. Sometimes I lock it out when going up long hills. Not that its going hunt, I just dont want it going back into OD if I happen to let off the gas. It likes to run at 2000 RPM's. Which is 68 for me.

LeRoy