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Discussion Starter #1
My truck has a 5k linear POT and it is set to shift into overdrive at about 40mph. When cruising along, no load, between 45-50mph if you let off it drops down a gear. It will not coast in overdrive unless you are going above 50mph. Any ideas?

Thanks,
Matthew
 

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idk but my truck shifts into OD anywhere betweem 35-38 mph and won't downshift until I get closer to 30 mph. I love it like that. It coasts nice.
I don't know what I can tell you that would help though, unfortunately.
 

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Check for a stuck or maladjusted TV cable, the cable from the IP to the trans. Contrary to popular belief, this is not a kickdown cable. It varies throttle valve pressure which in turns afffects shift timing. (It also raises line pressure with throttle opening).

I originally thought that overdrive shifting was independant of throttle valve pressure (because of the use of the TPS), but I'm not so sure now. I had extremely early, soft 1-2 and 2-3shifts and could not get full travel of the accelerater pedal. I also had the hunting and back and forth shifting of overdrive at lower speeds. I found the TV cable to be stuck. After correcting that my shifts are normal as expected but the overdriving hunting and shuttling is gone as well (unexpected). May have been unrelated and coincidental, but worth checking, especially if you have anything abnormal about your 1-2 and 2-3 shifts.

I could not find the procedure for adjustment of the cable and it does not adjust like the old style, so I just adjusted it to a normal shift feel and timing.

Hope this helps,
Steve g.
 

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Put a 3-way switch on it. One way turns overdrive on manually, one way turns it off manually, one way lets it shift automatically just like it is now.
 

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Discussion Starter #7
Thanks but no thanks. Would like to keep things working normally as possible. Any other ideas?
 

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I believe the down shift out of OD is related to the TPS, mine does the almost the same thing yours does.

At least it did 'til it quit altogether.
 
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