I Have a stock 97 F250 PSD with an auto. I have heard in the past that is not a good idea to tow anyting in OD. Somthing about the pump not moving enough fluid to keep things lubed/cooled. Is this valid or is it OK to tow in OD(not pulling hills mind you just on the flats)?


Dan

 

I wouldnt tow over 5k in OD. alot of guys dont prefer to tow in OD at all for exactly the reason you stated, but as fast as i drive, its usually ok.

 

it's ok to in od,but don't let trany hunt!

kurt

 

depends on how fast youre going really. if youre on the interstate running 70-75 youll be ok. but if youre cruising around at 50-55, id take it out of OD. mine is a 5 speed, but 4th and 5th gear are the same as drive and OD in an auto, and i honestly dont think i could run 70 in 4th gear without being wide open. i towed 8k from tennessee to ohio, up hills at 60-65 mph, and never left 5th gear the whole way. so power wont be an issue in OD. but like you said, cooling will be.

if you plan on doing a lot of towing and your truck has the stock tranny cooler on it i'd go outside right now and take it off and throw it in the recycle bin. its not even enough to keep the fluid cool on a half ton truck that doesnt tow anything. jasper wont even warranty their own e4OD if you put a stock cooler back on it. so that should tell you something.

 

Similar question - I pull about 2-3000 lbs. on a daily basis, no hills. I do most of my driving at 55-65, and some 40-50 in town. My truck does have a transmission cooler, I'm not sure whether it's stock or not. It also has a shift kit, which was in the truck when I bought it. Should I stay out of O/D, or am I okay? Thanks

 

I tow in OD all the time and always have. Towing in OD will not hurt the tranny (auto) as long as the transmission is not hunting for a gear. In other words shifting up and down at short intervals.

My loads vary from 2-3k to 18-20k, it doesn't matter to me. Now driving in north Texas is not like dring in Tn. Our hill are abit lower and farther between.

 

with only 2-3k lbs i wouldnt even worry about it. your truck doesnt even know its there. basically where you run into problems is youre cruising along in OD and every time you touch the pedal to go around a slower car or up a tiny hill and it starts searching for the right gear. if you can accelerate around another car without having to down shift, then youre fine. generally any rpm above 2k and youre ok in OD. and it varies a lot with gearing too. a 4.10 will be at 2k rpm and fine with just about any load in OD at 55-60 mph where as a 3.73 may need to be going 65-70 to keep the rpms up enough to use OD with the same load.

with a stock cooler and no towing at all, i wouldnt expect more than 150k miles out of e4OD. we got 90k out of my dads towing a 4k lb camper and 160k out of the one in my bronco with no towing at all. i put a remanufactured one in my bronco and jasper told me they would void the warranty if i put the stock cooler back on. i put the one they sell on it and it has a lifetime unlimited mile warranty. got it from auto zone. advance only had a 3 year 36k mile warranty. same with o'reillys. so if anyone is looking for one, go with auto zone.

 

I would second this. My previous pickup was a '95 F350 auto psd and I towed anywhere from 5K to 20K. I've pulled all over Kansas as well as all over the Northwest in the hill and mountains.

I lost a tranny in one pickup because I was letting it downshift itself in the hills (hunting for a gear).

After that experience and because I should have known better, I based what gear I was in by my speed and RPM's. Anything 70/72 mph + I towed in OD. If I got into some hills and had to slow down under 70, I would manually hit the OD button and downshift. If running on the flat under 70, I would usually just leave it in underdrive. Have never had a problem since.

In overdrive at 70, you'll be pulling right around 2000 RPM's which is on the low end of the power curve and will start lugging and start "hunting" for a more sustainable gear. The same speed in underdrive will put your RPM's at 3000 - 3100 which is on the high end of the curve. So I would say if you can sustain revs above 2100-2200, then run OD. If not, use underdrive. If over 2100 and you get into the hills and can't sustain revs, then downshift.

My 2 cents.

 

I tow on a weekly basis...from an empty trailer to a 10k boat to 38 ft campers.....I only take it out of OD when I am in town or the trans is hunting between 3-OD....As others have said....X the stock cooler for an aftermarket......the stock cooler I would not even use as a power steering cooler

 

X2

Bill

 

If you have 4.10 rear end gears, you just about have to put the truck in OD if you want to go over 50 MPH.

As others have said, don't let it hunt. If you're using the CC, you will have to downshift for it. To prevent hunting, the shift points are really moved way apart to prevent hunting when the CC is engaged.

 

ok...possibly dumb questions, but I need things explained (sometimes more than once) in terms of my own truck

the only thing I ever tow is my 18-ft tagalong trailer and two horses- about 6k lbs total, give or take. I had it drilled into my head when I started driving w/trailer to NEVER EVER leave OD on (that was with '97 Expedition).

my 96 250 (3.73 gears) = ~2300 rpm to maintain 60/62 mph on the highway w/trailer. I won't really go any faster than that no matter what just because of my precious cargo. Truck is stock except for susp lift, shocks, and tires.

so- I'm probably safest to keep on with OD off?

 

hmm, you should have 355 or 410's unless you installed the 373's. the 2300 rpm is that in 3rd or od? what size tires are you running? my truck has 4.10's turning 35 inch tires. i tow in od all the time, i will only pull to 3rd if i am coming up to a long hill but that is more for peace of mind since i dont have gauges and cant moniter egt's. i have lots and lots of trouble free miles on the trans and i tow way over 6k.

 

...definitely meant 3.55...I need an "embarrassed" smilie right now

but anyways, the 2300 rpm is in 3rd, I've never experimented w/leaving OD on. I have 35s right now but they're pretty much finished. The new ones might be 36 or 37 when I get them

 

I do not have gauges yet either. So what I have been doing is keeping the speed down to 60 and OD off. That puts me at 2500 RPM with 265-75s. On the hills I just watch the tach and maintain 2500-2800 RPM. I shift down when I need too and keep what ever speed i get in that RPM range. Until I get some gauges and do a few mods that will have too do I guess. Oh yea the load is a 9000#ish fifthwheel.


Dan