OK guys..... You've got me out of trouble a couple times now, so I've come back to you again.

I have a 2000 F150 V8 4.6L, I have not checked which tranny yet. The truck drives fine up to about 40mph, then all the sudden I have nothing. Truck seems to be in neutral. If I turn off overdrive, everthing is fine. RPMs don't seem to matter, around 40 mph seems to trigger it. The overdrive light does not flash. Engine runs fine. I have been driving with overdrive off for a couple days and you wouldn't even know there is a problem, the problems only appear with overdrive on & over 40mph. With overdrive on, I can coast down to 30mph or so and the tranny will reengage untill I get up to 40mph again.....

Fluid levels are fine.

I have seen several posts with some simptoms I had noticed before, occasional hard shifts, and very rarely a slight shimmy like driving over a rough section of road lasting 1 second or so..... Seems many people have had these symptoms, but I have not seen any final posts saying what had been found.

I've seen that the slight shimmy could be the torque converter locking and unlocking very quickly, but I am not sure exactly how this relates to overdrive and why I would have no trouble with overdirve off.

Sorry about the long post.
Thanks in advance for any help or even guesses.....

 

I've heard of a similar situation on older 150's w/ E4OD's:
Over time, the OD wiring on the column gets worn and eventually shorts to chassis ground, engaging OD after 1st or 2nd gear. You have to pull the column apart to change it out. Last I heard, the entire shift handle must be replaced. Not sure how much $$.

Your trans is probably a 4R70. I'm not sure if this fix would apply to it or not. You will probably have to trouble shoot it down to he wire to be sure.

Have you tried pulling codes?

Tony

 

Hi F150Tony...... Thanks for the reply....

I'll have to take it someplace to see if any codes are showing up.

I made it to the weekend though, so I'll look into the column suggestion......

I just jumped over to the F150 Online Store to look at the Hypertech Power Programmer. Can this be used to read error codes? The brief description there does not mention this........

I also saw the Superchips MicroTuner which says it is an OBD II diagnostic code reader. I already have a Superchip installed. I guess I could go with either Computer Programmer. Anyone know if one is better than the other?

Thanks again F150Tony

 

if you wanted to save some $$$, autozone will read the code for free.

 

Thanks plug....... There's one right around the corner. I'll try that tomorrow.

 

Mark, I am hoping you found what was wrong with your trucks trans. Mine started doing the exact same thing today. I sent you an e-mail. If you respond to either it will be fine.
Thanks.

 

Hey WLF

You too huh?

My work schedule has been so busy I have not even had time to take it to even be looked at yet.....

I've been just turning off overdrive.

I'll let you know when I do find out, but I don't know when I'll have the time...... Probably when it goes completely out.....

Sorry for not having any info for you........

 

No problem Mark. I too will let you know if I find anything out. I am hoping it is a servo or something electrical.

 

Hey WLF

I saw a tranny shop in my travels todays and stopped in. I discribbed the problem, he took the truck for a test drive, and gave me his best guess. He said there is a drum that at speed (with the overdrive engaged) will throw out a pin or key which causes the overdrive to engage. He said these pins will sometimes stick, or be thrown from the drum resulting in no overdrive. He said he would have to open it up to know for sure. He estimated $900 to fix this possibly if that is what it is...... more if the torque converter is also bad...... I will probably have several people look at it before I decide what to do.

I'm sending this to your e-mail address and posting it........

Hope this helps some.......