trans.problem

[achevyman]

I`ve got a 1998 c3500 6.5 td with a 4l80e trans. My issue is at speed in o/d my torque unlocks when there is no load on the trans. If I accelerate torque locks up untill speed levels off,then unlocks again. I dropped it down to (D) from (OD) and truck started surging, any input would be appreciated.

[gmtech4]

as you can see i have a 93 truck with a 6.2

 

KEEP THAT IN MIND OK?

 

my truck does this ,i asked a GM tech from another site about it .....he said it is the engine speed sensor at the back of the engine where the distributor would go on an old gaser

 

he said that is the sensor that the PCM uses for the tranmission...i have not repaired mine yet ,i put in a switch for when mine acts up

 

so that is my answer to you but KEEP IN MIND that there is 5yr difference and different tranny etc etc etc

 

have it diag'd,,what im saying ,is ,,it could be at least 4 things to cause it

 

let me know

[achevyman]

I appreciate the quick responce,guess I`ll have to bite the bullet and spend on diagnosis. Hopefully it`s just a sensor. Will let you know.

[CapitalTruck]

You ever hear what was wrong wth your truck.