Farmer2

I have a 95' F150 supercab with 5 liter and 4R70W trans.
The truck has 112k on it.

I have this problem that started like over night. It happens all the time when the truck has set for over 8 hours. After driving it for say 2 to 3 miles it goes away and operates fine. I have no codes or lights flashing on the dash.

The problem is the TC stays locked up after driving out of 1st gear. It lugs hard going into other gears due to being locked up. When I come to a stop it lugs hard and drops the rpms to about 300 and then something releases and its ok until I go again. This same cycle will happen until I get the 2 to 3 miles on it, like mentioned above. I have found that if I put the selector into 1st it bypasses the lock up thing some how. I then put it into drive and start out again and then after it shifts its back again.

I have since completely drained the TC and trans and changed the filter with no change of anything.

This is driving me nuts! Has anyone heard of this?

Thanks, Dave

390wagon

i work on a lot of 94-97 f series trucks and i've seen a problem almost like yours but on these as soon as you put it in drive it stalls, converter locks up right away, putting it in low its fine(no lockup in first gear). it has always been the speedometer, amazing but true.attached to the instrument cluster is a sensor that tells the lock up how fast your going and when they go bad they seem to think youre going 100 mph at the time so it tells the converter to lock up pronto. could also be the solenoid pack in the tranny but that(usually) makes the overdrive light flash on the shifter.

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68 Ford Country Sedan Wagon-390 FE, C6, 9 Inch
87 Chevy Caprice Classic Wagon-307, 2004R, 10 Bolt, what can i say, i grew up with that car

Farmer2

While this was happening to me, I noticed the light on the shifter handle flashing while towing a 6000 trailer last week. I didnt think it was related so I didnt mention it. How do I test for this speedometer or cluster in the trans? This may be my problem.

Thanks, Dave

390wagon

i can't remember how we originally determined the cluster was the culprit, maybe just unplugging it? may also throw a code, tranny definitely will so a scan tool would be your best bet at a quick diagnosis.

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68 Ford Country Sedan Wagon-390 FE, C6, 9 Inch
87 Chevy Caprice Classic Wagon-307, 2004R, 10 Bolt, what can i say, i grew up with that car

Farmer2

Thanks for the help. I will scan it tomorrow with the snapon box our mechanics have at my work.

Dave