* Tranny will not shift under load? HELP! *

[blue72]

A buddy of mine just purchased a 2002 F350 w/ 40" tires, 12" lift. It has a Banks 6er on it with guages. Induction, exhaust... Anyway the transmission will not shift under load when the truck is cold. Once the truck is warmed up, shifts fine??? I do not know if the tranny or torque converter is stock or not. Any info is appreciated!!! Thanks guys!

[maddogv21]

So let it warm up and then drive it.

[blue72]

Anyone else...

[SuperSnow]

I have what sounds to be the same problem with a bone stock F 550. It will not shift for the first few miles of driving, but then all of a sudden when it warms up, it is fine the rest of the day until the next morning and we do it over again. As for Maddogv21, letting it idle doesn't help in the warm up, mine has to be driven, it could idle all day but needs to be driven that first 2 -3 miles.

I originally had the overdrive on / off light flash, got code and replaced the solenoid pack. Light never came back on, but same problem.

Also tried output speed sensor and MAP sensor - both a no go

If I come up with anything else I will fill you in. Keep me posted on your status.

[Austinj427]

Have you hooked a scanner to it?

[SuperSnow]

I was informed it may not be tranny / torque converter issue, because the engine isn't sending enough power to tell it to shift. Does this sound right? I was also told possible IPC sensor, any thoughts?

[Tyler]

Depending on the temp, the truck WILL shift into all 4 gears, but it NOT lock the converter until it gets to a warm temp.

[SuperSnow]

Mine is a little diferent then because I can't shift out of second as I can't build any rpm's. Top speed under 30 for first 2 -3 miles then she warms up and won't do it again.

[Tyler]

Originally Posted by SuperSnow

Mine is a little diferent then because I can't shift out of second as I can't build any rpm's. Top speed under 30 for first 2 -3 miles then she warms up and won't do it again.

Then I have no idea what that is. I've never seen it.