I was driving my 1998 f-150 on the highway on cruise control and my truck accelerated all the way up to 5000 rpm and now it feels like it won't shift out of first, and jumps to 3000 rpms automatically when driving it, and ideas?

 

I'm sure you've made sure it's full of fluid.

 

Yes that was the first thing I did.

 

What engine does your truck have? From that I can make an educated guess as to what transmission you have. I'd hate to diagnose an E4OD and find out you have a 4R70W and what I told you doesn't apply.

 

It's the triton 4.6 l

 

It's a 4R70W transmission.

The first thing to try is to get the codes read. Often that will lead right to the problem. You could have a bad shift solenoid, stuck shift valve, or a bad intermediate clutch, or something I haven't thought of.

 

I am also having trouble with my transmission, same as yours but mine kicks out of over drive once the truck has been driven for an hour or so. I changed the fluid and filter a few weeks ago but it's still doing it. Any ideas what could be the cause??

 

My guess is that something is wrong. If you would provide some specifics about your truck (year and engine would be a good start) I might be able to narrow that down some.

 

It's a 2000 f-150 4x4, it has the 5.4 with the 4R70W, I think that's it.

 

It can be many things. Have you checked for codes? The places that read codes free CANNOT read the codes you need.

This might take a high end scan tool that can look at live data to see what input is getting a bad signal when the unexpected shift happens.

 

My engine light isn't on, and my o/d light doesn't blink. But I will try to get it scanned to see, hopefully it's just my o/d solenoid.

 

I can guarantee you that it it isn't your O/D solenoid as that transmission doesn't have one.

D

 

I'm almost positive it does, I've changed every solenoid except that one. I already have it, just haven't dropped the pan and put it in. It may be called something other that o/d shift solenoid.. There's a shift solenoid for 1-2 and one for 3-4. The one for 3-4 is what I'm referring to as the o/d solenoid. But if it isn't that, do you have any idea what else may be the problem. Like I said, it doesn't do it until I've driven it for an hour or so then it starts kickin out of O/D and just revs up. If I take over drive off then it runs fine in third. Let it cool down some and it goes back to normal. And I haven't been long replaced the filter and fluid. I double checked the fluid to make sure it wasn't too high or too low.

 

Here is the application chart and the shift solenoid pack. There is also a solenoid for the torque converter clutch, but I didn't include that here.







As you can see there is no dedicated OD solenoid. Overdrive is obtained by energizing both shift solenoids at the same time.

D

 

Well I'm glad you cleared that up for me, would you have any idea on what may be the problem?