hey ya'll i have been viewing yoru post for some time just neevr posted anything myself.

my question is. yesterday out of the blue somthign went wrong with my transmision.

when i come to a stop it seems to be having trouble going all the way down to first. right befor the truck comes to a full stop it will shutter almost like its going to stall out then goes into first and is fine. then on take off it will take off just fine but then shutter again going into second. any other time it seems to be just fine. the problem only happens in a stop of right at take off.

now i do have a rather good know how about trucks and have always done my own repairs. but this is the first thing to go wrong with this particular truck.

also when i shift it manualy everything seems to be perfect.
so that tells me its not a machanical problem but instead maybe an electrical onewith what ever tells my truck when to shift.

it feels just like somone that has trouble with a manual tranny.
as if it dosnt know if it should shift or not and lets up the clutch to fast.

info about my truck is as follows
98 f150 xlt
2x4
4.2L Auto

what i dont know is what to look at first.
any help would be great.

 

It sounds like the torque converter clutch is stuck on. There is no hydraulic pressure to apply the clutch in first gear, so it does unlock just before coming to a stop.

It could be a stuck valve, a bad solenoid, a wiring problem, or a bad PCM.