problem going into drive when cold

So this has only happened twice, but in order to prevent screwing my transmission up, I figured I'd ask. I have an '01 4WD w/a 3.4L V6 automatic transmission, and I'm about to hit 90k. Last week, and yesterday, I had problems shifting into drive, where it just did not engage. I would stop for about two minutes, cycle through all of the gears, and then drive off just fine. It has only happened when my truck has been outside, in the cold, for around 8 hours. At home my truck is parked in my garage, and has not had any problem going into drive.

After searching around a bit, I came to the conclusion that maybe there was a stuck valve, and that draining and refilling the tranny would be a good idea. I don't plan on flushing it (haven't heard good things about flushing 1st gens), but thought draining and refilling might be a good idea. All I would have to do is remove the plug and then fill it from where the dipstick is, right? And I can only use the Toyota reccomended fluid? I just wanted to make sure this is a good call before going any further. Judging by how nasty the front diff/rear diff/and transfer case fluids were, I'm not expecting it to look great. Thanks!

 

Okay so when you put the gear selector in drive the trans didnt engage? If you put it in 1 or 2 will it go? Any check engine light?

 

could be that the shift adjuster is sticky, lube it up

 

I tried 1 and 2 and it didn't engage either...And no I haven't had a check engine light as long as I've had it (3 months).

Where should I lube the shift adjuster from? I'm not entirely sure where it's at.

 

connects from the lever in the cab to the transmission, its on the drivers side, when ever it snows or ices here mine freezes up