My overdrive light started flashing yesterday, trans. started shifting hard. Scanned it with my lap top using my Total on board diagnostics. No codes.
The truck drives and shifts fine UNTIL it wants to shift into overdrive and then the OD light on the shifter starts blinking and the hard shift begins. I drove it to work today ( 9 miles one way in traffic) with the overdrive switched off and it ran, shifted fine. I am going to drop it off tomorrow at the dealer and have them look at it. Any ideas of what this could be?
Thanks in advance.

 

The flashing OD light is like the check engine light for the trans. Your fluid may be getting too hot, you may have a bad solenoid, or you may need a complete trans rebuild. I would check the fluid, make sure it's not too full but has enough fluid, and make sure it is not burnt / is the right color.

If you are bored you could take out the speed sensor and clean that up and see if that solves your issue as well.

 

Have you figured out your problem mine done the same thing this evening driving home from work it didn't shift hard or anything but it started flashing about half way home so I pulled over cut the truck off turned everything off and started it back turned my lights back on and it acted fine after that I would like to know what could cause this to maybe knip it in the bud before it causes a problem this is my dd and my only vehicle lol

 

Unfortunately for me my torque converter is shot as well as most of the transmission, getting a complete overhaul right now. The truck has 200k on it and i used to pull a big boat with it. I am not easy on the vehicle. Its been a great truck. First major issue ever.

 

That sucks man I really hope mines not that bad mines got 218,285 and I pull a couple different bassboats with me and such if you don't mind me asking what is it costing you to have the trans rebuilt?

 

Mine did all that at 185,000 miles. Changed the fluid and installed a shift-kit. 339,000 miles on her now, works great!

In the E4OD's Ford first used what's known as the worst trans fluid ever formulated. It's been discontinued long ago..nasty stuff. It was called Mercon. Sound familiar ? Yea, it's not MercV.

So the fluid was one problem, it heated up then broke down. The other problem was material/contamination build up in the accumulator or valve body....easy to remove and clean up.

Anyway, before going to extremes, give that a shot first. All cleaned up, shift kit to help (100 bucks) and GOOD trans fluid (Amsoil being the best), you should be putting power to the ground again most.

 

Sorry for the delayed response. A little over 3k with all new parts and a lifetime warranty. I put 235mi on it yesterday and it shifted well. Although the evening I brought it home, I broke out the creeper a good flashlight and my headlamp and crawled under it to check for leaks or ? I found the two cross member transmission mount nuts COMPLETELY loose. Luckily the shop was near my house and I found it right away. I took some pics and torqued them down. There is a reason why I repair everything on this truck I can myself!