Hi all,
I changed the transmission fluid and filter today on our 2006 Buick Rendezvous with a 3.6L V6 and AWD. The pan was nearly coated, about 1/8th inch thick, with what appeared to be a blackish-gray metal sludge. The magnet had about 1/4th to 1/3rd of an inch of metal sludge on it. The fluid was also varnished, telling me that the trans has overheated on multiple occasions.

What does everyone think? Does it seem like the transmission is on its way out?

P.*. As far as I know, the fluid has never been changed. We bought the car with 39k miles on it, and it currently has 99k miles. The service interval for transmission fluid and filter is 100k, so I am assuming it has not been changed until now.

Thanks for all help!

you cant go by gm'* service intervals for trans or coolant. i usually go 60k for each because ive had issues waiting. you should put a external cooler on it. you put the dex IV in it?

I put Dexron VI in it.

thats what i meant. hadnt finished my coffee yet

I figured. Well, I just worry that, judging by the state of the fluid when it came out, the trans is already on its way out if it has been overheating like this. It doesn't downshift smoothly when you manually downshift it to second. The whole car jerks, and then it shifts.

i think most do that if you arent on the gas. i dont know anything about autos besides maintenance, hopefully some of the people who do will be along shortly.

i went for many years never having one auto, now you cant hardly get a manual in anything nice.

Right, that'* what I thought. But here is where it gets weird: it downshifts smooth when I'm NOT pressing the gas, but when I am pressing the gas (not far, just moderate pressure to maintain speed) is when it downshifts harshly. It'* so strange to me.

Spencer, Unfortunately if you have that much smaller particulate (not metal shavings) found in the pan, (probably be clutch material) it may be only a matter of time before things start to slip in clutch packs. One thing about automatic transmissions is true, heat & broken down friction modifiers (overheated fluid) without putting fresh fluid in kills them. Considering how hard trannys work, I change my Dex 6 out more often than many owners at 40k miles period. If you only dropped the pan you have not changed all the fluid (lots unchanged in torque converter)
SO here is what I would do. First off get the sticky varnish away from check balls etc (weird shifts) in valve body by using this: Trans Tune | Sea Foam Sales Company
Add a full can, drive it for 1000 miles, and see if the trans improves while it cleans and then change the fluid and filter again and see if there is more particulate matter in there.
The other product I use in all my automatic'* is Lubegard. This keeps the fluid much cooler! LUBEGARD Automatic Transmission Fluid Protectant