1994 Explorer, 2wd, 180,000 miles
Tranmission has around 50-60,000 miles on it since it was rebuilt.

Couple days ago i changed the transmission filter/gasket/fluid.
However, I forgot about the o-rings on the filter because the new one didnt include them and the transmission shifted really bad because of that(slipped out of gear, took a long time to go into gear, etc.)
I redid the fluid and filter and put the o-rings on there this time.
Now it seems to shift fine when im driving but it takes a long time for it to initially shift into drive.
Ex: i put it in reverse (which takes it a second at the most from when i move the shifter), back out of my driveway, stop, and shift the shifter into drive. when i shift it into drive it takes a few seconds (like maybe 4-5 seconds) for it to actually shift into drive.
It didnt do this before i changed the fluid and filter. also there was no significant amount of metal particles on the magnet in the tranmission pan and the filter looked pretty clean.
another thing i noticed that may or may not be related is that it seems to idle a little slower than usual all of a sudden.

Any ideas what may be wrong. I have to drive back to school this weekend now that spring break is over so hopefully its alright.

Also if your are going to tell me something like i need a new transmission or something else drastic (and expensive) dont bother cuz i dont need that stress.
A few things i am going to try tomorrow is unhooking the battery which maybe will reset any computers controlling the tranny. Also i am going to buy some of that tranmission additive and see if that helps since maybe some of the seals inside the tranny arent use to the clean less thick transmission fluid.

Maybe the delay is ok it just concerns me since its longer than it was before the fluid change.

 

I'm sure you've already checked this, but what you're saying sounds like a classic underserviced tranny. Is you're fluid level correct?

Where it was good before the filter change, It would be a huge coincedence if it developed another problem right after. Check the forums for more info on the tranny. I haven't had any problems with mine (yet).

 

The fluid was decent before the switch. The main reason for the change was the filter had been in there so long and i wanted to change it.

I have checked the fluid a lot after the change and there is plenty in there and it looks alright. Im going to keep checking it though.

Today i also checked the vacuum modulator to see if there was any fluid in the hose to that like was recommended in the forums but the vacuum line was bone dry as it should be.

Also i drove it on the highway today a little to check it out and it seemed alright except for that it maybe was shifting a little later than usual. When it shifts its smoother than it did before the fluid switch though.

The only thing i can think of is the change in consistency of the fluid is messing with something. The new fluid is going to be much thinner than the dirty old fluid and maybe it is affecting how it works. When i described this problem to a mechanic before i reinstalled the filter the second time he said the shifting was weird because of the missing o-rings on the filter which was causing it to suck air instead of fluid. Maybe the air bubbles from that are still in the system and i still need to work them out.

Maybe its alright but I am just trying to figure out what it is so something worse doesnt happen to it. Unfortunately i have to drive it 230 miles back to school tomorrow so hopefully its alright and nothing happens to it. Im just going to stop a lot and check the fluid and make sure it isnt overheating or leaking or anything like that.

 

Looks like you've covered the bases pretty well, sorry I wasn't much more help. Good luck on your trip...hope it all works out for you.

 

Alright i made it back to Illinois fine. It was kind of interesting because it looks like (i havent filled up again so i dont know for sure) i got the best mileage my car has ever got (over 20mpg) and the transmission shifted very very smoothly and didnt overheat or blow up. The delay in shifting was still there though.

Something that might be part of the problem is that when i stopped twice along the way the fluid level read a lot higher than before. If anything i expected the fluid level to drop as the fluid worked itself into the transmission more. Also the thing i think is causing the shifting delay has to be something vacuum related. When i went to put it into drive yesterday i noticed that the engine revved up slightly on its own before it finally shifted into drive. I think maybe there is a vacuum leak somewhere that is causing it to have to rev higher to shift it to overcome the leak. Im going to see if i can find one but it might be hard.