transmisson flush ?

hey i have a 97 grand prix se 3800 with 127k , it looks like the transmisson has never been serviced, i was told by some that when you flush a tranny with high miles that it may start to slip and shift hard, the fluid looks pretty dark, possibly burned, should i change fluid and filter and flush the system ? and if i should what would be the way to go , semi synthetic or just regular fluid , i hear mobil 1 is good stuff.
thanks for any advice .

Ted

Don't flush! Flushing will cause a multitude of problems. Change the fluid and filter and you should be fine. If the car has 127K then synthetic may not be the way to go due to the different lub. properties, it may actually cause the tranny to slip, although that is just a guess.

Ted- flushing the transmission may not be the best idea. I have heard similar stories about transmissions acting up after a flush. A simple fluid and filter change usually helps. Try a good quality high mileage ATF that meets the proper recommendations. I have had good luck with Valvoline motor and ATF high mileage fluids. Good quality high mileage ATF fluids have additives in them that soak into the clutches which promote quicker and smoother shifts and hopefully, prolong the life of the transmission. Similar additives can be bought seperately and added to your transmission whenever you wish. Do a fluid and filter change by the book and you should be ok.
On a side note- if you do encounter problems with your transmission, be extremely cautious about getting it rebuilt. Transmission shops love to tell you that you need rebuild and are used to getting the OK with little hesitation. They know that most people, even motor guys, don't know much about transmissions so they feel like they can get away with murder. Transmissions involve many vacuum related valves and lines that control its operation (i.e. the modulator valve). Be sure and do you homework on as much of these things as possible before an expensive rebuild.

Hope this helps....

thanks for the feed back gtp dad and nolan, i have grave concern about even changing the fluid and filter with that many miles on the tranny , too many horror stories about trannies being serviced with high miles that have not been serviced on a regular basis... the car shifts great
i wish the previous owner would have maintained the tranny as well as
they did with the engine oil.

Agree with GTP Dad... I'd still change the fluid and filter. Stick with conventional AT fluid and you should be ok.

Dealer flushed mine 5 months ago. Same dealer is in the process of rebuilding it as I type this. 57K miles and no hard driving. What bothers me is the procedure to get it fixed under warranty. They need a GM Tech guy to go to the dealer and verify it needs to be rebuilt before they will pay for it. The guy has 2 days to report there and my car just sits until he shows up. Then 2 days to order parts 2 days at least to do the job. Warranty pays for loaner car but not till the repair is approved-3 days. The whole thing really SUX! :disappoin

I go with wagon, I agree with Dad. Never flush a trans. Some dealers do it, so they can rebuild later.
http://img.photobucket.com/albums/v425/kustomkid54/logo9.jpg

alright , you guys have convinced me to go ahead and change the fluid and filter..... I'll post back and let you know how it went, and if there was any slipping in the future. thanks guys.

If you get it done and it slips, get GTP DAD to rebuild. He works for GM. That's a joke.
http://img.photobucket.com/albums/v425/kustomkid54/1998PontiacGrandPrixGTP001.jpg

lol @ kid ... i read a lot of posts from you guys .... thats funny you say that about GM i work at the cadillac plant where they build the cts-v and the srx and sts. that cts-v is a sweet machine