2001 EX, 5.4L, 4R100 TX, 282,K MILES
My Excursion recently did not shift into 3rd gear after entering a freeway. I thought the engine sounded strange and I glanced down at the tack and the engine was turning at about 3K RPMs and the TX was still in 2nd gear. I held it there for a few seconds and it wouldn't shift. I let up on the gas a little and it still wouldn't shift. I then ran it up to 4k RPMs and let up on the gas and it shifted into 3rd gear and then into OD. I was over 600 miles from home, getting ready to get onto the PA turnpike, and since it was running okay, I drove it as far as I could before hazarding a stop. I didn't want to take a chance that the next time I stopped it wouldn't shift into 3rd gear. Finally, when my bladder dictated, I stopped and checked the TX fluid level. The level was fine and the fluid was bright red. (I drain the pan every 30K miles and refill the TX with approx. 7 qts. of fluid - I realize that 7 qts. is not a complete drain.)
For the next 600 miles the TX shifted flawlessly. The torque converter locked up fine with absolutely no slippage. I am home now, but I don't trust the transmission. I frequently take trips of greater than 1K miles, and I don't want to have a transmission problem hundreds of miles from home, and far from the nearest service.
Does anyone have any idea what might cause such a failure? Any suggestions would be greatly appreciated. Thanks!

 

Did the OD OFF light ever blink? If so, there will be transmission codes stored in the OBD2.

That said, with 282k, good chance the transmission is nearing the end of its life.

 

The OD light never blinked. However, I will go outside right now and hook-up my scan tool in the outside chance that a code may be stored.
Thanks for your reply.

 

No DTCs.

 

You may need a more advanced scan tool that can read transmission DTCs.