96 explorer shifting issues

[Apple]

My wifes 96 explorer with an automatic has just started doing this about two days ago. While driving down a flat road it seems to be shifting in and out of O/D, but the rpm's don't go as high as when you turn off the O/D. It only does it for a couple seconds then goes back to normal. She drives about 18 miles one way to work and said it will do it once some times twice each way then acts as normal. I was thinking that it was the lock-up torque converter unlocking then locking back up, but I'm not sure. Any ideas on what it might be and how I can fix it would be great, or is it on its way out. Thanks again.

 

[adsm08]

That sounds a lot like the converter clutch cycling.

How long has it been since the fluid was changed?

 

[Apple]

I know it has been awhile since the fluid has been changed, I don't know how many miles it has been. It has 250,000 miles on it and everything is original other than routine maint. we have only had to change the alt., blower fan and an idler pulley up till Feb. this year when it had a head gasket blow out so I rebuilt the top end and now this. I have talked to a ford tech. and he thought that it was the throttle position sensor, so I changed it last night and I'm waiting for her to come home from work to let me know how it did. Hopefully it worked, I don't like her driving my F-150 when the deer are running this time of year.

 

[adsm08]

It is possible that the TPS could cause this, but you mentioned RPM change. I just got done dealing with a bad TPS on my truck and it had no noticeable affect on RPM during the bucking.

Its hard to say without the vehicle right here. I'd hook it up to a scanner and go make it do it. Check your trans fluid, if it's nasty, dark, etc, get it changed just for maintenance reasons.