Sometimes Lockup OD Works 1999 5R55E

[Dangerfield]

Hello: I have a 99 Explorer XLT 4x4 with a transmission overdrive bug. Usually first thing in the morning when I head to work the tranny will shift into overdrive just fine. But about a mile or so further down the road when I stop at a stop sign and take off again it does not go to overdrive and the O/D light flashes. I can stop and shut off the ignition, restart and again sometimes it works but most of the time it doesn't. Something that seems to help it work properly is if I shut it off, restart and manually shift up through the gears. But I have to get the engine rpm's fairly high at the shift point in order for it to go into overdrive. A few weeks ago, the darn thing worked fine for about four days. But now the bug is back. If I have to get the tranny rebuilt, so be it, but I am worried that won't fix it if it's not a mechanical issue.

I could sure use some experienced based advice. Thank you!

 

[JK080]

Start with getting the codes, the flashing light is to let you know that the computer has seen a problem with the tranny. If we could get this code it would shed some light on what is going on.

Based on your description of the problem I would think that you will end up with a torque converter problem (lock up).