Transmission Slippage

I have been told by a mechanic that my 2001 Alero (94,000 miles) has a transmission slippage problem and that the transmission needs to be replaced. Is that true, or is it possible to make adjustments to the transmission? It jerks (but not always) when the car is shifted into reverse and drive. Oddly, the problem is more apt to occur when the car is warmed up and not when it is cold, such as when first shifting after the car has sat all night.

Thank you for any advice you can give me. -Lowell

I'd recommend getting a basic tranny service with your mileage. Pan drop only no flush consisting of new ATF and a screen filter.

However, it sounds like your problem may be the intake air temperature (IAT) sensor. When it acts up or goes bad the tranny acts up just like the symptoms you have. The IAT is located after the MAF sensor but before the throttle body on the rubber intake duct. Cost around $10.00.

When my IAT went out, it was shifting hard in every gear, all the time. Do you still think it could be his IAT since he's only getting occasional hard shifts? I don't know much about tranny issues, so that's why I'm asking.

- Jeremy

Jeremy, After reading my post again, I think I probably left the wrong impression. The transmission does jerk most of the time - probably about 90% of the time.

bnaylor, Thank you for your advice. That would be a cheap way to find out if that's the problem. However, because of my deficiency in the gray matter department, can you explain for me precisely where the throttle body on the rubber intake duct is located - as I would stand facing the front of the car? And would the IAT be inside or outside of a tube or hose or whatever?

Thanks again. -Lowell

Its located on the right hand side of the accordian rubber intake duct. The red arrow in the pic points to it. Just undo the electrical connector and pull it out to replace.

http://i5.photobucket.com/albums/y186/lizzywiz/iatshot.jpg

bnaylor, Thank you for the picture and the red arrow. Even I could read that. I was able to get into town this afternoon to buy the IAT Sensor ($14.20+tax), but when it was installed, it made no difference.

Now, if you have any other suggestions, other than a new transmission, I will appreciate it. -Lowell

Well sorry to hear that but it was worth a try. It doesn't look good. You could do a pan drop and see what may be sitting in the pan like metal shavings or pieces. Other than a pan drop service consisting of replacing the ATF and screen filter there is not much you can do. Sounds like you'll need professional tranny help.

Was it ever scanned with a trans capable scanner to see if there are any stored DTCs?

when my tranny was slipping it was also the IAT, but when i replaced it i had the same problems so i took it in and they told me that a lot of the time the connector also goes bad, which cost me $25 from the dealer, but i installed it myself and so far so good



kevin