Hey,

My dad just bought a 2003 f-150 4x4 7700 and it is shifting kinda weird on the highway. He tells me that when its the first time its been on the highway for that driving time, it will be in O/D revving 2300 at 100kmph(65 mph). Then he goes about 5 mins like that, and its like it shifts again and drops down to around 1850-1900 rpm. After that he can stop and speed up again and it will stay at the lower rpm. I was just wondering if anyone knew what was causing this, and if it was normal or not. The dealership told him there was nothing wrong, the truck does have warranty for another 8 months so would like figure it out before that. Thanks.

 

Sounds like the torque converter ain't lockin initally. How cold is it where you are? The ECM will keep the converter unlocked when really cold to build some heat. The 4R100 is a pretty tough tranny so I really wouldn't worry if it is workin normally otherwise.

How many miles on the truck? I don't like any more than 30K on the fluid before a flush. Some fresh Mercon/DexronIII (not Mercon V) will do ya good.

Adrianspeeder

 

Hey,

The truck has 32,000 km on it right now, and the temp in the mornings there would be around -10 to -20C, and will be getting colder soon. Thanks for the reply.