How cold can a E4OD run before causing tble? This time of year in the OK Panhandle, mine runs around 100 degrees when towing. Climbs up to around 150 in town. Summer towing is around 150 degrees. In town is around 180. Thanks, Bob

 

You can run as high as 250F before you need to start worrying.
Normal operating temperature is 150-180F.

Mark

 

Don't know the specific answer to that and I am not an expert but...

Way back when I had my first tranny rebuild. The owner of the shop, who was a good friend of my boss, told me a few things about trannies. At the time I had just blown up a tranny by overheating it, so naturally he recommended a tranny cooler and me thinking bigger is better, I told him to put in the biggest one he had. He said actually that was not a good idea since a tranny can run too cold. He didn't say it would destroy itself but he did say it wouldn't shift properly and as smoothly as it should. He said whatever cooler I used, I should run it in series with the Radiator tranny cooler. That way the engine water temperature would warm up the tranny fluid to about the right range and the auxilliary tranny cooler would keep it from going too high.

My 94 F250 with E4OD, was rebuilt about 20,000 miles ago. I don't know if I never noticed or whether it always did this and now I was paying more attention, after the rebuild I started to notice that when the truck was cold it would take longer for the tranny to shift to OD. It would take maybe 2 miles of freeway speed driving before the RPM Gauge would settle to the normal range I always see, plus the tranny either wasn't shifting to OD or the TC wasn't locking up until it had run those few miles(BTW I am up to freeway speed right after leaving my driveway).

I don't claim this is normal but it has done this for as long as I have paid attention and it is worse in the winter. I also think my Chebby car does the same thing. I think it is due to the fluid being thicker at low temps and causing delays in the shift body. It might also be built into the computer to cause the tranny to run at higher RPM to get the fluid up to temp, I don't know this, just swag.

So, long story short(never happens with me I guess). It is better for your tranny to get upto operating temperature but I don't think you would have a problem unless you regularly hit big minus numbers. And if your engine water is heating the ATF, eventually it will reach operating temperature.

Good Luck,

Jim Henderson

 

My 01 F-350 4X4 V-10(4,500 miles)shifts the same as you say yours does when cold. Just takes longer before it will shift into od. I have noticed this on my mother in law's Mitsubishi Montero also. It may just be a normal thing. I don't know if letting the engine warm up a bit more before stating off in cold weather would have any effect on this or not. I actually have the opposite concern with my od. It shifts into od at just 40 mph if you have to let up on the gas a bit at that speed. I feel this is too soon as it then seems to lug a bit until you get up over 45 or so. If you are getting up to speed on the freeway and are able to keep your foot on the gas it shifts into od at closer to 50mph, which just feels better.