Now somethings wrong with my f-150's transmission

[jbaer619]

I love fords but the one big flaw that everyone of them I have ever had is the transmission!!!! This also happens to be the one part on a vehicle that I'm not really comfortabe working on.. So I was hoping you guys could help me out with some troubleshooting... Its a 99 5.4l lifted automatic f-150 and origianally what would happen is when I would get on the gas it would jerk when shifting into 2nd (but when I was easy on it it wouldnt do this) then recently it started not wanting to shift into 2nd unless i rev it out to around 4k rpm and let go of the gas, and it will still take a couple seconds for it to finally shift. So what do you think is wrong with it???

[Adam McLaughlin]

What trans did you get? Did you get the 4R100 or the 4R70W?

Also.. Did you check fluid level? Are you full of fluid when parked and idling on a level surface? Do you have any trouble codes?

Right now I am going to bet that your VSS is not getting to the EEC, and that you have the 4R100 transmission. They behave funky when the VSS doesn't get where it needs to be, and I mean EVERYWHERE that it needs to be. All of the way to the dashboard, the computer wants to see it everywhere in the signal train.

Hook up a scan tool and watch while you are driving, make sure that the VSS signal tracks with the movement of the truck. I lost a dashboard module once and the truck didn't want to get into second gear unless the motor revved to the moon, and then the engagement was extra harsh.

Adam - Self employed trans guy for nine years.

[jbaer619]

well I finally got around to checking the codes and all it was was that damn gas cap code that I always get, but i'm not sure about what type of tranny I have, how would I find out. And might it be something with the valve body or whatever it is that controls the transmission? like maybee one of the valves are clogged or something?

[Adam McLaughlin]

Did you hook up your scan tool and watch the truck in trans mode while you were driving? Did the VSS track when you drove down the road?

Does your speedo work?

I can help you best if you answer the questions as posted.

Adam