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Author Topic: Towing with 1999 f 350  (Read 928 times)


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Towing with 1999 f 350
« on: November 06, 2016, 09:13:41 PM »
I am towing various trailers of various wieghts with a 1999 f 350. It has an automatic transmission. Most loads are rather heavy. Should I be towing in or out of overdrive at highway speeds? Should I be in or out of overdrive while accelerating up to highway speed?

JW of Opechee Shores

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Re: Towing with 1999 f 350
« Reply #1 on: November 07, 2016, 06:26:38 AM »
You don't say gas or diesel and not sure what transmission you have in your F350 but in my 32003 F350 7.3 PSD I put the transmission in Drive with overdrive on and let the transmission do what it was made to do. That said I don't tow in a mountain area, and a lot of guys will say take it out of Overdrive. I only take it out on downhill grades to let the transmission slow me down and save on brakes.   
F-350 7.3 PSD
Cameo 36FWS
Hooked up and ready to go always: Ok so I do need to stop at a rest area now and then:)

Gary RV_Wizard

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Re: Towing with 1999 f 350
« Reply #2 on: November 07, 2016, 06:31:09 AM »
Unless you find it shifting excessively, in and out of OD while cruising along, just leave it in Drive with OD on. The tranny will figure out the correct gears to use 99.99% of the time.
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

Lou Schneider

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Re: Towing with 1999 f 350
« Reply #3 on: November 07, 2016, 10:13:10 AM »
One thing to be aware of is whether the torque converter is locked or unlocked. The transmission will do what feels like a half gear downshift with the engine RPMs rising a couple of hundred RPMs when the load is enough to make the torque converter unlock.  This is designed to let the engine run a little faster while accelerating or climbing a hill, if it's routinely run in the unlocked mode it not only heats the transmission fluid but you also lose the efficiency of a direct connection instead of the torque converter slip.

If you're running in Overdrive with the torque converter unlocked, your transmission will be much happier if you downshift to 3rd (direct drive) and let the converter go into lockup in that gear.
« Last Edit: November 07, 2016, 10:21:16 AM by Lou Schneider »


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Re: Towing with 1999 f 350
« Reply #4 on: November 07, 2016, 10:54:30 AM »
If it's not struggling on flat land, use the OD.  If you're towing in the hills or it's hunting for gears, drop it out of OD.  Either way, a trans cooler and trans temp gauge is a good idea if you don't already have them.
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Re: Towing with 1999 f 350
« Reply #5 on: November 08, 2016, 05:52:53 AM »
Your tranny is a 4R100 and if it shifts in and our of OD a lot.......lock the OD out to stop that. Lots of shifting in and out will just build up a lot of heat in the trans..
2008 Ford F250/CC/SB/V-10/2018 Montana 330RL