my truck (98 k1500, 4.3) does not run right on the highway. when i get on the highway my rpms stay where they should be around 2100. but after a while they jump at least 2500, whie im still going the same speed. i think its my torque converter clutch disengaging when the trans warms up. i drive alot of highway miles and its costing me alot of money . any help. is the clutch disengaging, and do i need a converter and does trans temp affect it.

 

Hey isrummell,

How ya doing today.

Have you changed the transmission filter recently? Change interval is @40K and they wind up largely ignored.

 

it was changed since i have had the truck but its not quite time yet i have been watching it

 

working same issue. poss converter. i'm going from coasting around 60mph to applying gas and get a downshift before tranny catches. same thing as you also with the higher rpms at highway speeds. i have a rebuilt trans with only 35K on it. i've been told torque converter and to add an external trans cooler if not already done.