4R70W TC Stays Locked Up
 

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

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

The problem is the TC stays locked up after the shift into first. It lugs hard going into other gears due to bing locked up. When I come to a stop it lugs hard and drops the rpms to 300 and then something releases and its ok until I go again. This same cycle will happen until I get 2 to 3 miles warmed on it. I found that if I put the selector in first this will not let the TC lock up when I come to a stop. I then put it into drive and start out and it acts up again as mentioned.

I have completely drained the trans and TC and changed the filter with no change to the problem.

This is driving me nuts. Has anyone heard or know what is causing this?

Thanks, Dave

RE: 4R70W TC Stays Locked Up
 

Sounds like to me you may have a lockup solenoid sticking in the on position or the lockup valve in valve body is sticking.