1991 Explorer can't begin driving in Overdrive

[bitsnpizzas]

I have looked for an answer for this for quite a while now and haven't found a solution yet. first let me say what it is doing. I have a 1991 Explorer with automatic transmission. For about a year now, it doesn't like to be in O/D. What I mean by that is that if you shift to O/D and push on the accelerator from a dead stop, it just revs up and barely rolls. If you start off in D, it drives fine. But of course if you are going 70, it is revving around 3000. It will let you shift into O/D at this range, anything above 45-50 mph, but if you exit the interstate for example and come to a stop and forget you have it in O/D then it will just rev up again and not roll.
Sometimes, when the engine is cold, it is reluctant to shift up while in D, but if you ease up a little and give it a chance to shift, it does so and it drives fine like that until the engine is cold again.
I can pinpoint when it began, and it has to be related but I don't quite understand how. It began the night I ran out of gas at a stoplight. I got it started again and revved it up quite a bit to keep it running. It died anyway and after putting gas in it and starting it back up, the problem was there. I could barely get the truck rolling through the parking lot while it was in O/D which I had always driven in up to that point unless hauling a trailer.
does any of this sound familiar? Please help with suggestions if you can. Thanks!

 

[natenkiki2004]

The gas thing has to be a coincidence. Check your fluid level, if it looks full then maybe add a bit more, no more than 1/2 quart and see if it improves. If not, it might be worth dropping the pan and changing the fluid/filter. OR, you might find a local transmission shop to do a diagnostic/maintenance on it, adjusting the bands and testing it.

 

[arco777]

Sometimes, when the engine is cold, it is reluctant to shift up while in D, but if you ease up a little and give it a chance to shift, it does so and it drives fine like that until the engine is cold again.

This particular symptom is unrelated. The governor valve sticks in the cold on higher mileage A4LD transmissions, typically due to sediment in the fluid which scratches and binds up the governor. Keeping clean fluid and a high quality filter can help the governor not bind up, and Sonnax makes a larger governor weight to improve the condition. It is not too hard to access; if you have a 4WD model you need to remove the driveshafts and then the transfer case (easier than it sounds). On a 2WD model I believe you only need to remove the tailshaft extension housing.

 

[arco777]

Definitely do a band adjustment. If you do a search on the forum there is a how-to thread.

If this doesn't help, I'd suggest dropping the valve body and looking at your OD apply solenoid, and doing a teardown and cleaning couldn't hurt.