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Would you put new ATF in this? (pan pic)

803 views 2 replies 2 participants last post by  wmorrison65 
#1 ·
I am doing some "targeted surgery" on my daughter's '01 A4 transmission valve body. But that's not the point of this thread.

The point is, to work on the valve body, you obviously have to drain the fluid and drop the pan. Then you get into the "advice" (fact or myth depending on your view) that changing fluid on an old transmission may cause it to fail afterward.

There's a lot of debate on that. I feel if a transmission fails after a fluid change, it was already damaged. The logic seems to be, "crud" was holding old, hardened seals together and the new fluid dissolved it and caused a blockage somewhere. Kind of like a stroke for your transmission. Or, clutches have lost most of their friction material into the fluid, and it's the gritty fluid that keeps them working.

Anyway. If the fluid isn't burned and full of particles, and the transmission pan looks normal, is that a good sign that the transmission is probably in good condition, and it's probably safe to refill with new fluid? (I know there are no guarantees.)

Here's a pic of her pan. About 160K miles on the car.

https://ibb.co/ctmLDsj

When I drained it, I cleaned around the drain plug first and drained into a clean bucket, and covered it. About 5 or 6 quarts.

There's about 2 or 3 quarts (didn't measure) in another container, caught when removing the valve body. I don't count on this second batch being clean.

Question is, after I get the valve body reinstalled and am ready to refill (yes, car is level off the ground and I have VCDS to monitor temp while filling,) am I better off to:

1. Put in about a quart or two of new fluid, then reuse the first (clean) batch of used fluid, and if I run out of that top up with the new fluid, or
2. Use all five quarts of new fluid I have, then top up with the old if it needs more, or
3. Get some more new fluid and only put new fluid back in?

The whole "never change old fluid or your transmission will fail" thing is a bit scary. I'm working on my daughter's transmission to try and avoid a ~$4K bill for a rebuilt transmission. It's worth a shot since I'm not spending a lot for parts, with the idea that if it fails after that, I haven't wasted much money on it.
 
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#2 ·
I’ll be at this point about midsummer. Her 09a tranny was low and I added fluid. But, there are other issues to sort as well.

Personally, I’d run all new fluid.
 
#3 ·
Master mechanic I trust at VW took a look at the pan and said that looks pretty good, he wouldn't worry about new fluid causing a problem. So that's what I'll do.

I suspect most of the time people say don't change very old fluid is because, to really tell the transmission's condition, you would have to drain it and drop the pan, so without doing that it's safer just to top up. Unless you have kept up with scheduled fluid changes from the beginning, in which case you should always continue.
 
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