I don't know what is up with my transmission, when i am driving along on the hi-way, usually on a long trip, it will randomy rev up to like 4k rpms, the transmission is about 2 years old and the warrenty went out already, it is an E4OD on a 1994 f-150 w/ 4wd 351W

 

Check the fluid level, if it's alright, try changing the fluid and filter.

 

It's most likely the Transmission Range Sensor (TRS), which used to be called the Manual Lever Position Sensor (MLPS.)

It's on the driver's side of the trans where the shifter attaches. Replace it. It won't set a code until it completely fails, but the repeated downshifts will destroy your trans before the TRS gets bad enough to set a code.

 

where can i get one of those

 

Any dealer would have it, and I've heard that many parts stores carry them, too.