i have a 01 f150 4wd supercrew and it started happening just out of no where when i am accelerating normal when it goes to shift into 2nd gear right around 10-15mph it wont shift it will stay in 1st gear up to around 5k rpms and will stay there until you let off the gas why is this

thanks

 

anyone

 

Whenever I hear about a shifting
problem with a 150 I think look into
the history of the trans fluid.
Has you fluid been changed every 30K ir 15K if
you tow?
If not, then it is a good time to do it.

Make sure you use MERCON V specd only
Plane Mercon is no good for these trans.

Even if the dipstick looks clean the
additives have worn out.

 

I would take it to the garage and have a tranny flush done it might clear up your problems

 

I'll bet it's your accumulator spring for the 1-2. If you know what you're loking for and how to do it, it's easy and cheap. Try and search for pics and more on accumulators, usually the 2-3 goes or as well.

 

When this happened to my '99, it turned out to be the 1-2 accumulator spring. Pull the pan and you'll see a large snap ring holding in a piston. Pull the snap ring and the piston will drop out along with a large spring. If the spring is in two pieces, replace it. Also a good time to replace your fluid as well (pull the plug on your torque converter if it has one). The spring cost me $10 at the local dealer, and is specific to the motor size. It's an easy repair if you're handy with tools.