Well, that is how myths get started; it should be our job to dispel myths, not keep them going.

Kimberly, go ahead and change the transmission fluid. Chances are the gasket that is on there is still good, but you will have to inspect it to make sure.

Regal Guy, you are confusing transmission flush with a pan drop fluid change. A transmission flush can remove deposits that might be masking an issue, and there is a lot of discussion on whether to do that on older transmissions. Personally, I feel any transmission issues that arise as a result of a system flush were going to pop their heads up in the near future anyway.

On the other hand, doing a pan-drop fluid and filter change does not create the issues a flush might create.

So when the new fluid cleans up some sludge in 200k transmission that was never serviced and plugs up some passage on the valve body I wonder what will happen??
There is no right answer on this maybe nothing will happen. Maybe it will plug up a oil passage and burn up the transmission.
This can go back and forth all day long.
Apparent many have had problems after the transmission was serviced and many have not.
It all depends on the transmission and with out looking at the pan to see if its full of clutch material and metal shavings.
No one can say what will happen.

You can go back and forth all day ... I am going to say this once more. A pan drop filter change will not disturb anything. In the absence of your own knowledge you are relying on what you heard from others, and you are confusing what can happen with a transmission flush with a pan drop oil and filter change.

We have serviced transmission'* with as you say a pan filter change and there was problem'* afterwards in our shop.
Things run hotter in Texas and have more wear then in snow belt were you are.
So we know first hand by experienced.
Not from a web page
So i would not touch it with a 10 foot pole.

When you show me irrefutable evidence that supports this claim, I'll let you continue posting here. Otherwise, I can't allow you to post such claims as this. This is the only warning I'll give.

Well I've followed this pissin contest for awhile so thought I would add my 2 cents worth. Although I'm more of a manual tranny guy, what I know about slush boxes is flush no, pan and filter drop yes. In fact GM does not recommend flushes, only the radiator cooler if needed. Of course their dealers promote them as a profit center. I can't see where a pan and filter change along with replacing that inadequate rectangular magnet with 2 donut magnets and some fresh Dex VI would hurt. If the transmission goes after that, it was ready to fail anyway. Floating clutch particles in old fluid is basically what the old time used car dealers did to get the car a few miles off the lot, dump some sawdust in it.

2004 Bonne SLE 4t65-E 151K
1971 Chevelle SS M-20 wide ratio 4-spd 210K