I have a 1999 Ford Explorer 4 Door Sudan XLT 5.0L V8. This is my 4th Explorer since 1996, all second hand. I bought this a week before Christmas as my 1998 Explorer (which I had for 4 years) went down due to a timing chain issue. I was told by dealer seller that this '99 had a rebuilt transmission. But on Christmas Day, when I drove it, the check gauge light came on. Turned out I was lacking oil (even though I just had an oil change a few days before). At a gas station, I accidentally added 3 quarts of 10w 30 oil (found out later that this model recommends 5w 30). No sooner as I started driving again, the red check gauge light went off and the O/D OFF light started flashing continuously and would not switch off despite repeated attempts to touch the O/D button.. Did not notice any change in driving with this light flashing. There is a slight moaning sound from the engine (which has been there since I bought it) but nothing alarming. It has 167,500 miles on it so I expect a little rough ride even though the Explorers I've had were all comfortable rides. Well I drove it 30 miles and no issue. Once parked and engine shut off, I guess it reset. When I started it up again, the O/D OFF light stopped flashing. The owners manual says to get this serviced. Online bloggers say either new transmission, torque converter, speed sensor, corroded wires or the ground wire needing new insulation. Well, I hope it is that simple as wrapping the wires but I am afraid of taking it in to a shop and finding out it needs another transmission. That would cost more than I bought this for.

Can you keep driving with this light issue, and if so, what could happen later?

I love Explorers but why does FORD do such a bad job with these transmissions, door locks, latches, starters, etc? They should recall them all and fix the issue for us loyal customers.

bought 99 ford explorer 1yr ago its the xlt 4x4 auto with the 4.0litre sohv,when i purchased the owner said the overdrive came on and flashed! he stated he had an overdrive solenoid installed because it made the rpm's elevated and used more gas! i didn't get 200 miles when the light came back on,i bought as is so no recourse i removed trans pan but seems what looked like 5or 6 solenoids so i put new filter and fluid in and that didn't fix problem since that I've figured out how to get it to speed and feathering gas pedal and light will most of the time not come on but now my 4high and 4low light continuously flash after getting in some sand so i decided to try the 4low dial on dash and after getting out of the sand i switched back to auto truck wouldn't switch back to auto(over revving) felt like i was in first gear,got under truck tapped on a motor attached to transfer case and it fixed it i thought but 2months later those 4high and4low lights keep coming on! truck runs and drives normal but i don't light lights on my dash flashing please give me some suggestions on possible problems and repairs other than that this is my 2nd explorer i love them!