trans shift????

ok well this last weekend i dron my 02 alero to nebraska. once i got into high gear and was cruzing it was great and on the accel up it fine. but everytime i came to a big hill where the transmission could probably shift down a gear or stay in high it would almost act like it was slippin or it was down shiftin and up shiftin one of the 2 not sure which. no lights on or anything so i dont think its missin it still runs fine or at least its the best running car i ever been in if it is missing. anyone now what the problem is

What engine and how many miles on it ?
Have the fluid levels checked!

It does Sound like a typical problem with the 4t40 series transmission, which your car has.
A fluid & filter change wouldnt hurt, I wouldnt recomend a flush. :nono:

If this continues, down the road, it will probly need to be serviced/rebuilt. Not cheap! :grinno:

ya i think im gonna try that and see if it helps i guess lucky me i know a guy reall well that has a transmission shop but its still gonna cost parts so it probably wont be to cheap. i noticed it today when it goes to shift into high gear around 45 or so it keept wantin to down shift like it coulnt make up its mind what it wanted to do other than this i aint never had no problems with it at all

I've had mine in the dealer about 8 times for the same problem. I tried the tranny flush as the dealer recommended and it did nothing but cost money($250). They did many adjustments and changed many parts. The last was the TCC switch and the pressure switch. These helped, but still cuts in and out sometimes. My car started doing this at 50,000km and they still can't fix it at 80,000. My next attempt will be the spark plugs.

The problem is mostly due to pump pressure being to low or not enough fluid volume.
If your Alero is 2003 or later it shouldnt have these issue(s).

The pump impeller and shaft are small on the pre 2003, this was an update made - with larger components along with many other things.
Other then a rebuild or replacement I dont see it just "going away".

Not to long ago I rebuild one of these tranys, here is the link, it has a few details and costs.
http://www.automotiveforums.com/vbulletin/showthread.php?t=708108

Good Luck guys!

ya i guess on the bright sie of things im pretty good buddies with a guy in town here that rebuilds trannys for a livin. i been tryin to catch him at home and see what he thinks or knows. thanks for all the help. was just hopin it was something simple i could do my self