Need some help figuring out whats wrong with my Tranny.
Wanted to start with you experts... since my truck is way out of warranty now...

This is in a 2001 Expedition, 2WD, 5.4 Triton, Automatic with 107K miles.
* Issue : Transmission cant make up its mind what gear to stay in. 3rd, 4th or OD
* Issue : Transmission shifts 1 > 2 fine, 2 > 3 fine, then hunts back and forth between 3&4 if running steady speed between 35 and 50. Also happens with gradual acceleration between 35 and 50.
* Issue : Transmission hunts back and forth between 4th & OD above 50 up to 70; either running constant speed or accelerating
* Note : When the hunting is occuring there is no apparent slipping, because you can feel the shifts. They are NOT hard shifts. This truck hasnt shifted hard since the day we got it in 2001....
* Note : When the hunting/shifting is occuring, the RPM variance rises and falls around 300-400 RPM.

* Service notes :
- Tranny flush around 92K prior to a 4K mile road trip.
- Plugs by dealer at 65K

I am going to be dropping a data logger on the truck tonight for several days.

 

Are you getting anything that feels like shuddering or missing? Has the OD Off or SES light ever flashed? Have you ever had it scanned for generic and Ford-specific OBD2 codes?

 

Hooking up the scanner/logger on the way to the office in the morning, so I will see what comes out of that.
No lights at all, OD or SES.
The only sense of a shudder would be when its hunting gears, and my butt meter says it feels like its doing it when it gets the gear after changing... even at that, its an ever so slight tug.

 

I'm trying to help you determine if it's simply a low-grade misfire instead of a tranny issue. This is common when one or more coil-on-plugs gets weak.

 

Replace the neutral safety swich and adjust it properly when you install the new one. Then check the throttle position sensor if that doesn't get it.

Darrin

 

it might be a sensor

 

Are there any codes or data that would show a COPS problem, or is it symptomatic guess work?

Have to go back after another data run today or tomorrow.
So far, the data shows:
* No Error Codes
* Throttle Position dropped to -1 after I got above 10%
* MAX 364 / AVG 287 RPM swings when it kept trying to change gears @ 65...

It does feel like its rough idle (when sitting still and parked) at around 1900-2100 RPM; oddly enough about the same RPM when the problems happen around 65.

 

Not really - unless you want to pay the dealer to stress test them. If you suspect bad cops, it's cheaper to buy a whole new set off Ebay and be done with it. That's about 80 bucks, preferred vendors are Uneek Supply and Global Automotive. Search for "DG508".

 

Well, once again, I think GLC hit the nail on the head.
I captured this data on the way to drop one of my girls at dance last night.
The acceleration curve is me turning under the bridge by the house and heading up the entrance ramp onto 290 here in NW Houston.

Based on everything I have read, seen and now observed... I am going to go do a set of COPS, TPS, IAC and while I am under there, clean the TB.

Question.. .should I swap plugs too while I am under there? They have ~45K on them.


In the first blip, the RPM dropped from 2430.25 to 2087.75 then back to 2364.25.

The full run from the house to the dance studio looks like this.

There is a blip there towards the end too.
Speed was 65.86535 MPH @ 1937.75 RPM then blipped to 64.6226 MPH 2150 RPM.
The RPM then rolled down to 2102 @ 65.86535 MPH then 1964.25 RPM @ 66.48672 MPH.

 

what plugs did you put in?

 

The Ford stealership did it with the 60K mi svc. (that happened at like 63k).