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Discussion Starter #1
All of a sudden the tranny is acting up and the overdrive light is flashing.Any ideas?
 

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its throwing a code, you'll have to pull codes and go from there
 

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daddystoy
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When mine did that the Torque converter was shot and started to chew up the rest of the tranny. You can get the code read for free from pretty much any tranny shop.
 

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When it starts flashing you have something internal wrong with the tranny. Usually the TC but possibly something bigger.
 

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Demon Dually
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The O/D light flashes when either the torque converter is slipping excessively, or one of the shift solenoids are not working correctly or at all for that matter. You need to get it hooked up to a quality scanner asap. If you keep driving it like that you will burn up the tranny real fast. It goes into limp mode when the light is flashing which puts full line pressure to the trans which gives those neck snapping shifts which are no good for anything inside the trans let alone your neck. This will overheat the trans in no time flat and cook it.
 

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Discussion Starter #6
thanks alot guys,i will have the codes pulled thursday and go from there.
 

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Discussion Starter #7
well,i found a running parts truck with 100,000 miles on it.and bieng my block had a crack and the tranny was acting up i naturally decided to swap em out together.motor runs perfect,but i still have the same trans issue.so i may have a good spare trans sitting in my yard.
i guess thats what yo get when you ASSuME
cant wait to get this code pulled monday.
 

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Demon Dually
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If you swapped transmissions and still have the exact same issue then you have an electrical problem. I would pull the trans harness and look for signs of damage.
 

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Just another OBS addict
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Did you look at the codes? Like others mentioned, a good bet is that its the TC if you still used the old one, or the new one could be bad (though obviously theres a slim chance it is). But just my .02
 

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Former Ford Trans Engr.
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If you swapped transmissions and still have the exact same issue then you have an electrical problem. I would pull the trans harness and look for signs of damage.
I wouldn't do that. I'd check the codes first, then I would know where to start looking.
 

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I'd listen to Mark. He was an automatic tranny tech for Ford for a long time. Mine did the same thing after getting too hot and it ended up being a bad TC. I took the opportunity with the tranny down to put in a 5 speed instead and I'm quite pleased. Also, if you have extra cash for a rebuild look into BTS(Brian's Truck Shop). I have no personal experience with them but the common phrase associated is "the last tranny you will ever buy".
 

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I know nothing...
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Mine was flashing when i 1st bought it last year. I put a tuner on and cleared the code. It never came back and i tow 20k gross regularly in the heat with the ac on and in O/D. I was told by tranny rebuilder that a code can be thrown for several reasons that have nothing to do with the tranny mechanicaly. But I'm also lucky!
 

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Actually Mark was a transmission engineer.
 

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Mine was flashing when i 1st bought it last year. I put a tuner on and cleared the code. It never came back and i tow 20k gross regularly in the heat with the ac on and in O/D. I was told by tranny rebuilder that a code can be thrown for several reasons that have nothing to do with the tranny mechanicaly. But I'm also lucky!
Yeah from my limited understanding there are a few things that can trick the computer into thinking that the tranny slipped. Supposedly only a 50 rpm slip can make that light flash.

Actually Mark was a transmission engineer.
Nice. Even more reason to trust his word on tranny topics.
 

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Demon Dually
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According to the last post by the OP, he stated that he has already changed out the motor and trans ans that the old trans and the new trans are both causing the O/D light to flash. I can only think of three things that would cause that. If he reused the original converter and it is slipping, bad wiring harness or connector issue, or the PCM has a programming issue.
 

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Just another OBS addict
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According to the last post by the OP, he stated that he has already changed out the motor and trans ans that the old trans and the new trans are both causing the O/D light to flash. I can only think of three things that would cause that. If he reused the original converter and it is slipping, bad wiring harness or connector issue, or the PCM has a programming issue.
My thought exactly, and the other 2 are definately valid points
 

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Discussion Starter #17
i didnt reuse the converter.pulled some codes for speed sensor and 603 regarding kam "keep alive memory"?
 

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I believe you get the P0603 code every time you scan the computer. It's perfectly normal from what I remember but it has been a few years since I've scanned my truck. As for the speed sensor, is your speedometer working? That sensor is in the rear end from what I remember. They are known to get gunked up and give false readings.
 

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Discussion Starter #19
im also getting po708...trans range snsr?
 

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It's P0708 not O. It should show up in green. Hopefully Mark will have some insight. He is the master when it comes to these transmissions.
 
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