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Hi guys. I read in the FAQ that you should turn the overdrive off when driving around town and up hills. I will be doing some hilly driving and around town but I won't be hauling anything. I have a 97 E350 Van 7.3 TD with auto trans, 45K miles. I have never heard of doing this but I read that it keeps the trans life longer. Should I push the button when I drive around town and then turn it back on when on the highway? Thanks.
 

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That goes against what Ford says but, if it makes you
feel better, have at it! I've only done that when I'm
pulling max weight around the speed where the trans likes
to shift into OD. That's about 43 mph for my truck. I
do it to just keep it from shifting so much. When I'm
not towing, I never take it out of OD. Never had a reason
to. /ubbthreads/images/graemlins/shrug.gif
 

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You should leave the truck in OD. If you really need to switch it off, it will do it for you. It was designed that way... turning it off "*MAY*" do more harm then good as you will be turning everything faster and putting more wear on it.
 

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I find one of the easiest ways to tell is by looking at my trans temp fluid gauge...if the temperature of the fluid is getting up there close to 200°, then it's time to drop it out of OD in many cases.
Having decent tranny cooler also helps prevent hot fluid obviously, as the stock unit really isn't big enough for those of us that tow!

The only time I hit the button and take it out of OD around town is when I'm in stop and go traffic, or if there are red lights from block to block...thus keeping the transmission from shifting into OD...when it will again have to come right back out (because of another red light).
Or, if you are in hilly terrain, have it out of OD...until you are up to speed ( 45 - 50 MPH) then back into OD again...helping you to pick up speed etc.
It's best to judge what works for you best, but the idea of it being there is so that you aren't lugging the engine/tranny making excess heat, and it's the heat the kills trannys in my opinion.

Dale
 

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The other reason to turn off the OD is that when you come to a stop with the OD on the coast clutches aren't engaging, but if you have the OD off then they do. Read the link below for more information.

I used to run in town with my OD off all the time. But now I leave it on unless I am in stop and go traffic or I am hauling something. Or I need to do some spirited driving in town.


coast clutch controller
 

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[ QUOTE ]
The other reason to turn off the OD is that when you come to a stop with the OD on the coast clutches aren't engaging, but if you have the OD off then they do.

[/ QUOTE ]
Why is that a bad thing?

I read the link and it doesn't tell me much more than I should buy their product. It also told me they don't spell real well.
 

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[ QUOTE ]
[ QUOTE ]
The other reason to turn off the OD is that when you come to a stop with the OD on the coast clutches aren't engaging, but if you have the OD off then they do.

[/ QUOTE ]
Why is that a bad thing?

I read the link and it doesn't tell me much more than I should buy their product. It also told me they don't spell real well.

[/ QUOTE ]

From their ad:
The E4OD Coast Clutch Controller manages coast clutch application automatically and provides extra support to the overdrive sprag & reduces the possibility of premature sprag failure, a common occurrence with the E4OD transmission. This sprag has often been known to take out the transmission case when it fails and blows up.

Some one with more details is SellwithSam in the archives he has some posts describing why this is important and why he added the coast clutch controller to his E40D heavy duty rebuild. AutoTrans actually makes the controller and they had a website with more detials but I can't find it anymore.

But like I said it probably does not matter that much if you are running around empty. But as I mentioned before if you are towing heavy often and hot rodding often it would be a good add on for your tranny. Plus it has to help the guys who use exhaust brakes on their trucks with an E40D too.

Tim
 

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you got it at least as I understand it.
 

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I keep mine off when driving in town. City driving is a killer on brakes and overheated transmissions. I turn the od back on when I am on the entrance ramp. I also keep it off when the freeway traffic reaches city driving conditions. When I use od in town I can feel it 'pulsating' so I just keep it off in town. Just me, you form your own opinions. /ubbthreads/images/graemlins/grin.gif
 
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