Chevrolet: GM Transmission hard shifts when hot, chev impala, gm transmission

Question
Hi Roger I have a 2001 Chev Impala with a 3.4, I am having a strange problem with the Transmission, when cold it works fine, if I have spent say 30 minutes in stop and go traffic it sometimes starts shifting very hard through all gears, if I stop the car, say to go into a store for five minutes or so and then drive off it starts working normal,  I drive mostly in the city so the problem usually happens every day, it also makes a whirring sound once it starts, sometimes just turning off the ignition at a stop light may stop the hard shifting for a while. I have had the transmission fluid changed recently but it made no difference Thanks for any help you can give.

Ron Dempster


Answer
Ron;
 HI; it sounds like there is something going on in the tranny, I would say to go to one of those tranny shops that have the 25.00 specials, this way they will tell you what it is that is wrong,  It will have to be put on the lift and the cover taken off to look inside of it. it might be a simple thing so do not wait till it will run you a few thousand to get it fixed  ok.