Badassford23
Full Access Member
Why I'm towing a car and
trailer should I turn the od off or should I leave it on it a 92 f250 351 in it
trailer should I turn the od off or should I leave it on it a 92 f250 351 in it
Towing
- Thread starter Badassford23
- Start date
Devon Harley
Full Access Member
Off.
'94IDITurbo7.3
HAMMER DOWN!
bobracing
Full Access Member
If the truck will pull OD on flat land, I'm told it's OK. Turn it off anytime you hit a hill or the truck starts stressing but turn it off before it shifts on it's own. The trans guy said the E4ODs built up to much heat and burn themselves before downshifting on there own.
I'd run the OD off until up to hwy speed, if not doing hwy speed, don't worry about using OD.
My two cents and the way I ran mine until the 5sp was swapped in.
I'd run the OD off until up to hwy speed, if not doing hwy speed, don't worry about using OD.
My two cents and the way I ran mine until the 5sp was swapped in.
Badassford23
Full Access Member
I turn it off when I take off from a stop light I get up to about 50 -55 then turn it back on and I turn it off when going up hills and some times I leave it off and drive about 55 I'm hoping to be switching to a idi with a 5 speed trying to fine a donor truck
Leave it on all the time unless it starts to hunt when towing, except going up hill and you loose speed and it wants to down shift. Your wasteing gas (fuel) by shutting it off at stop lights , I make mine shift into OD at 37 to 40 MPH whenever I can city driving, just let up for a second, it'll shift into OD.
bobracing
Full Access Member
Are you trying to burn up a transmission? Towing in OD at that low of an RPM is going to cause way to much heat into the trans. The small bit of mpg gain is not worth the wear and tear of shifting and heat will cause on the trans while towing. Beside the OP has a 351 gas engine and will probably need the extra RPMs for towing anyways.
I don't even care to run OD in town when empty, more shifting and TQ locking/unlocking putting more heat and wear into the trans.
Badassford23
Full Access Member
Ok thanks for all the info
Badassford23
Full Access Member
So I should just leave it on in till the truck needs it like going up hills and towing heavy loads like the off should not be lite up is that rite
bobracing
Full Access Member
This is kind of a butt dyno thing, if the truck feels "comfortable" pulling the load, basically doesn't feel like it's about ready to down shift, then you can run OD. I'd only let it run in OD once up to speed. If in doubt, just turn it off, if you're only towing a small distance, the mpg difference isn't going to matter.
Also, do you have an extra trans cooler? Something to add if you're going to do this offen.
You do as you please.
The torque converter locks up when shifting from 2nd to 3rd on an E4OD. When allowed to shift into OD, that is when the OD switch is NOT in the OFF mode, the PCM tells the transmission to shift into OD if and when all conditions are met, ie: tach sensor, VSS signal, the PCM energizes the OD solenoid which in turn actuates the OD clutch package. Unless you stay in 2nd gear manually, the TC lockup is direct drive in 3rd gear.
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bobracing
Full Access Member
Yes, this is why the manual lock-up switch is a popular conversion.
Also locking up the TC will help reduce the heat by not allowing the TC to slip, but having the TC lock-up isn't always desired.
The problem is OD allows more heat built up with the higher gear ratio (lower number), that is why a lock-up TC is needed on OD transmissions. As a side affect, a little better mpg.
As far as towing, that is another gear shift and TC lock-up to go thru (in OD), then a downshift when the throttle is applied, then back up when less throttle is used, expecially when running low RPMs in town. The trans is hunting for the right gear causing extra wear and tear for no reason. The newer trans do better at figuring out what you want, but the early model auto OD trans have very little "knowledge" on what you want it to do and "hunt" for a gear to find something for the moment, not what is needed.
Badassford23
Full Access Member
Ok thanks
Badassford23
Full Access Member
Yea I was thinking about a bigger trans cooler but I just want Do the diesel swap
lindstromjd
Black Sheep
I honestly think that's a terrible question to put to the masses. Everyone has their own way of doing things and will not be swayed by anyone else's arguments. Put a trans cooler and temp guage in it and do what feels right for your truck. If its happy in 3rd, leave it there. If it can handle it in 4th and not overheat, then let it be in 4th. Heat is what will kill your automatic faster than anything. Even 3 speed autos have a problem with it if you overwork them.
