Transmission flushing at home: Really easy, really effective

[BillAileo]

I highly recommend against using anything other than a fluid meeting the JWS 3309 specification in a transmission calling for that fluid. I believe one would be much better off having some old 3309 left behind rather than some new Dexron in this equipment. Dexron can kill these transmissions.

Bill

[philiXC]

I've been reading these posts regarding do it yourself ATF flushes for
the 5 speed auto trans. I also ordered the tubing kit from IPD. Rather
than fill the trans through the dip stick, why not just rig another
plastic tube to the return line and then let the transmission "suck"
the 3309 from a clear container with the new ATF ??? If the return supply line can be primed, then hopefully no air bubbles are introduced
into the tranny.

Based on your experience, what do you think ?

Thanks

[gibbons]

The fluid is pushed through the return line by positive pressure, not pulled through with negative suction. I was just lazy, I had a transmission filling funnel already, It's about 18" long and maybe 3" diameter at the top to fit nicely through the mechanicals.

[volvoshad]

I used the Mobil 3309 exclusively for my flush and fill, but I have seen synthetics like Redline and Mobil marketed for these transmissions even though I don't see JWS 3309 on the bottle. Has anyone used these products successfully?

[ArtSmart]

I'm planning on changing ATF myself too. However, something doesn't really make sense to me. If you start by climbing under the car and draining the pan, why do all the circus with the tubing later - just keep draining it from the pan. Let me explain the idea. Somebody mentioned here that if you get perfectly clear ATF running through the tube and then drive the car for a while it gets cloudy again (pockets of dirty ATF trapped inside of the tranny). So why not drain the pan, refill drained amount drive it, drain the pan again ...refill...drive - you get the idea. Each time just drain the pan and then let it mix well inside while you drive.

Advantages:

1. No need to mess with the tubes, try to run the engine and risk running engine with little fluid in the tranny.

2. Fewer refills. Let's say, you've got 7.5 quart of ATF in the tranny and you are planning to run through the whole case of ATF (12 quarts). With this method you will have only 4 refills

3. Better homogeneity - each time you mix up ATF well, before the next refill, so there are no pockets of the original (dirty) fluid.

4. Better results - that's just pure math:

Even assuming perfect mixing up of the fluid with your method you would get the following concentration of the original dirty fluid in the final mix-up:

1st refill (3.1 litter) - 58%
2nd refill (2 litter) - 43%
3rd refill (2 litter) - 32%
4th refill (2 litter) - 23%
5th refill (2 litter) - 17%
6th refill (0.9 litter) - 15%

In the drain the pan every time method you would get:

1st refill (3 litter) - 60%
2nd refill (3 litter) - 36%
3rd refill (3 litter) - 22%
4th refill (3 litter) - 13%

Not by much, but slightly better.

[BillAileo]

The point of the Gibbons/Volvo method is to get used ATF out with a minimum of mixing of the old with new which it accomplishes by the pumping out of generally unmixed old stuff. Under this method the engine is on only long enough to pump out each portion and no longer. The method you propose maximizes mixing.

Bill

[ArtSmart]

The point of the Gibbons/Volvo method is to get used ATF out with a minimum of mixing

Bill, try actually reading what I wrote! (Those little percentages in the end of the message might come handy in understanding my point)

[BillAileo]

ArtSmart,
FWIW: I did read what you actually wrote and a premise is the mixing of the fluid and the numbers are driven by that premise, which, in my opinion, is a false premise in a properly done Gibbons/Volvo flush in which minimal mixing occurs. If one assumed no mixing (which certainly would not be the case) the percentage of old ATF after just the second refill would be about 32% and it would continue dramatic drops at each refill. Of course there is some mixing so these numbers would be off by quite a bit. I prefer the Gibbons/Volvo method because it is basically the functional equivalent to the use of the automatic equipment used to flush these systems in a well equipped Volvo facility. However, I see no harm in your approach. I guess we will just have to agree to disagree.

Regards,

Bill

[ArtSmart]

in a properly done Gibbons/Volvo flush in which minimal mixing occurs.

Where did you get that from? As soon as you refil the ATF after that first 3.1 L that you drained from the pan, the fluid is mixed with the old fluid. Everything you pump out with Gibbons method from that point is mixed stuff. (may be with the exception of the fluid in the radiator, which you can drain first as well with my method). From that point, the better it is mixed the better your results will be(no pockets of old stuff) Try to think about it, why do you think people suggest shifting transmission while draining it with Gibbons method?

[BillAileo]

The method described by Gibbons is the method described in VADIS for doing a flush. In normal operation the ATF in the system is drawn from the pan into and through the transmission and then into the transmission portion of the radiator for cooling and then out the return line which is located at the upper portion of the raditor for return to the pan. By first replacing the fluid in the pan and then disconnecting the return line from the radiator to the pan when the car is started the dirty fluid in the cooler and the transmission is basically sent on its way through the vinyl tubing attached to the return line receptacle into whatever container is being used to collect the waste ATF while at the same time new ATF is drawn from the pan into the transmission and on to the cooler. VADIS does not call for moving the gear selector during the flushing process, it's instruction is to leave the transmission in Park. The instruction to move it between gears follows the filling process and is to be done before the final checking of the ATF fluid level.

Bill