I have an '03 ZX5 and on 12-26-04 it snowed 1 foot here in Southern VA, when I put the car in reverse and went to back up the car made this grinding sound that was awful, it did it all day that day but that was it. My friend has a ZX wagon and his does it all the time year round. i thought he was crazy. Any one else!

 

What does the Dealers say?

 

Answer:Kimnach Ford says that all small cars equiped with auto trannys that have electronic O/D have a selenoid in the bottom of the transmission pan, and when it gets too cold (teens)along with the cold tranny fluid the selenoid is kind off slow, also the tranny fluid is more viscous (spell) and it will take longer to warm up and provide lubrication.
Changing to sinthetic wont help and almost always it does it when in reverse because it is the highest gear located in the tranny. They say start the car and warm up for a minute or so tends to help. Also don't park car where the snow or ice can touch the tranny pan, bad.

ford should design something better

 

Smells fishy to me. I'd ask them to show me where they got the info on the solenoid, and have them make you a copy of all the TSBs they have for that car. TSB are technical service bullitens.
Sometime you can find them here but the site is limited: http://www.alldata.com/recalls/index.html

 

thanks! I am looking!

 

How many miles? Manual or auto? Have you replaced the fluid?