Okay, I did a little searching, but I'm in a bit of a hurry to figure this one out so I can fix it tomorrow. This is the second time this has happened. I'm driving in town on my way to school and my truck, while up shifting, decided to quit driving in overdrive and drive. It would just continue to slip until I shifted in second. After I shifted into second, it would drive, but I was revving like crazy doing 40 in second gear. The O/D light was flashing. I was at school for about three hours and the truck drove fine on the way home. I'm thinking an electrical issue but not sure where to start. Any help is appreciated.
Brad

 

It sounds like the torque converter is giving up, either that or the truck is very low on ATF.

 

Checked the atf. It's new fluid. I may change it just for the sake of it. I wanna be sure though, how many quarts and what kind does it take?

 

Start by reading the codes. It's a real PITA to do it from the dash, but it can be done. you short a pin on the diagnostic connector under the hood.

search for KOEO Codes, here's an excerpt -

Turn key to RUN.
You will hear some relays engage and the fuel pumps prime the system. This is the EEC beginning the test.
The fuel pumps will stop and the EEC will now begin giving codes.
You may catch a brief flickering of the light. This is a rapid code read that is used by the code readers you can purchase. Do not worry all those rapid flashes you just say flicker buy will now be given at a slower pace of �, 2, & 4 second pauses.
First digit of first KOEO code (1/2 second between blinks)
2 second pause
Second digit of first KOEO code (1/2 second between blinks)
4 second pause
Next KOEO code
Once all KOEO codes are read the EEC will repeat them
6 second pause
Single Separator Blink (this indicates the change from KOEO codes to CM codes)
6 second pause
Codes from Continues Memory (uses same 1/2, 2, and 4 second timing as KOEO codes and also repeats them)
If nothing has been recorded by the EEC since last battery disconnect you will see:
Blink – 2 sec – blink – 4 sec – blink – 2 sec – blink – 6 sec – blink – 6 sec – blink – 2 sec – blink – 4 sec – blink – 2 sec � blink
This translates into 11-11 current condition (KOEO) and 11-11 in the continues memory (CM); or SYSTEMPASS

I have an intermittent code for the VSS/PSOM and it's a pain but it's fairly rare so I haven't been doing anything about it. I have a cluster from the salvage yard and I have a plug for the rear at the diff but I haven't gotten around to replacing them to test.

Any of the fault codes will drop you out of OD and the OD light will flash. I'd start with the codes to see where that points you.

 

Plan on it but can't read em until tomorrow.

 

OD light flashing means you have a transmission related code.

 

~16 quarts of Mercon 5 transmission fluid.

Changing ATF Fluid in a E4OD and 4R100 transmission .: Articles

 

Your truck will display 3 digit codes. Warm up the truck before running the KOEO tests and Continuous Memory display. Otherwise you will trigger false codes for the ECT, ACT and TOT sensors.

 

That's for the entire trans and cooler set up. If he was to just drop the pan and filter, at the most he would have to buy 8 quarts

 

Why would I suggest to someone to do a half-assed job like that? Replace it all or leave it alone.

 

What he said ^

There is a proper drain/refill procedure for the E4OD in the link in my signature, if you care to read some.

 

So are you trying to tell me that you would rather never change your fluid at all than to at least drop the pan, change the filter, and put 8 quarts of fluid in it?

 

No, he said he wouldn't do a half-a$$ job and contaminate 8qts. of new ATF with who-knows-how-old fluid. And since he stated the proper procedure I would assume he knows how to maintain his trans. and that he does service his trans.

 

I am stating you should change all of the fluid aka "the right way" or leave it alone. Read into it whatever you want. Yes, I do most of my own service work on all of my vehicles.

 

i would try getting it pumped out little more expensive but worth it.