Tranny Flush

[Funmart6]

Should the filter be changed before or after flushing the transmission? Instructions at v8sho suggest changing the filter first then flushing, but wouldn't the filter become contaminated with old fluid if you did this?

 

[MilTownSHO]

When I do it I just drop the pan, change the filter and refill. Only changes about half the fluid, but thats all I want.

It seems you would want the new filter in there to catch all the contaminents while flushing out the system, but at the same time, its kinda like ruining a new filter...

 

[Mr. SHO]

Actually, dropping the pan and refilling changes about one third of the fluid or less.

The old filter has been collecting contiminants for several thousand miles. As it collects these contaminants, the filter actually begins to trap smaller and smaller particles than it did when new. So the chances that a new filter is going to "catch" anything that the old filter missed is about zero.

The old fluid may be dark and stinky due to the additives being essentially destroyed, but it certainly doesn't contain any appreciable amount of solids that wouldn't be flushed out with the rest of the fluid, new filter or not.

 

[SHOZ123]

If you flush as described.

1. Remove ATX cooler hose, run engine and pump old fluid until it slows into a bucket. (2-3 quarts)

2. Then drop the pan and change filter. (2-3 quarts)

3. The add 10 quarts and drain through the cooler hose again with the engine ruunning until it slows. (~8 quarts)

4. Then add 4 quarts and cycle through gears, get up to temp and top off.


When the filter is changed and the new fluid is added to the pan only new fluid is going through the filter. The rest of the old fluid is in the TC and is what comes out at the end of the sequence.

 

[Wess]

The BG folks claim that the chemicals used in their flush actually break down the particulate matter enough that you don't need to replace the filter.

 

[SHOZ123]

There chemicals may break down the carbon which would be like adding Berryman's B-12 to the fluid. But the additives aren't going to break down steel and aluminum.

 

[Wess]

There chemicals may break down the carbon which would be like adding Berryman's B-12 to the fluid. But the additives aren't going to break down steel and aluminum.

Won't the flush process remove the majority of these materials by pressure alone? I can understand maybe not in the filter, but sediments system wide?

 

[SHOZ123]

If your fluid has been neglected and left carbon-ed up deposits then pressure will not remove them. It is going to take a chemical or the new fluid with it's additives to clean this out.

Best thing to do with the SHO tranny is flush and change filter the factory way every 15k if using dino fluid or 30k on synthetic. Amsoil is the best IMO.

 

[Funmart6]

I know this sounds dumb as heck, but you do reinstall the pan before adding the 10 quarts right to begin the flush, right?

 

[Dylan]

I know this sounds dumb as heck, but you do reinstall the pan before adding the 10 quarts right to begin the flush, right?

Correct, unless you want tranny fluid all over the floor .

 

[Funmart6]

 

[Funmart6]

Roughly about how many quarts are needed to flush the system? I have read anywhere from 10 to 17 total. Which cooler line needs to be removed? Instructions at V8SHO are confussing with one person saying the lower line and others saying the top one.

 

[SHOZ123]

Roughly about how many quarts are needed to flush the system? I have read anywhere from 10 to 17 total. Which cooler line needs to be removed? Instructions at V8SHO are confussing with one person saying the lower line and others saying the top one.

The tranny holds 13.5 quarts. When doing the flush you will waste about two quarts.

Doesn't make any difference which line you use as it will come out of which every one you disconnect.

Laying on your back under the car on the drivers side of the OEM tube tranny cooler disconnect that line. Add a short piece of hose to the cooler and place both in a bucket.

 

[Mr. SHO]

I buy 3 qts of the cheapest MERCON I can find (usually ProLine or Coastal brand) for the pan refill, and 14 qts of quality synthetic MERCON (Mobil 1 is my usual brand) for the flush. Drain the pan, drop it, swap the filter, clean & reinstall pan, refill with the cheap stuff, flush until dry, overfill with 10 qts Mobil 1, flush until the fluid is clean and cherry red, top off with 2.5-3 qts, drive around the block, top off again, and use the last bit of fresh fluid to do a partial PS fluid change.

On the 97s at least, the ATX cooler is the tube WITHOUT fins. The PS cooler is the tube WITH fins.

 

[Funmart6]

I had a successful tranny flush last night. Here is what I found.
When I pulled the filter, the pink gasket stayed in the trans, no problem getting it out though, but this suggests to me that this filter could be old. When I drained the pan, the round magnet in the bottom was covered with a black slimey goop but the rest of the pan was clean. Now if the Ford mechanics changed my fluid last July wouldn't they have cleaned the magnet and also if the filter wasn't very old, wouldn't the gasket have stayed in place when the filter was removed? The fliud looked pretty clean and red but had a strong smell to it. I used regular fluid this time but would like to change to synthetic, I added some Lucas to the fluid as well. Everything seems to be shifting very smooth now with no more hard shifts or jerking. I will see how it is after a couple of weeks. Now I know that if my problems come back I am looking at a rebuild. Thanks for all the tips guys, I had never done this kind of thing before and you guys were a really big help, Thanks.

I used Castrol DexronIII/Mercon fluid.

 

[SHOZ123]

Yes the gasket and aluminum ring usually stay in the tranny filter port, originally the gasket is orange. Not hard to get out. I would think anyone who took the pan off would have cleaned the magnet. If a flush was done more than likely the pan never came off.

 

[Mr. SHO]

If a flush was done more than likely the pan never came off.

That would be consistent with what most dealerships are doing these days. They don't bother to drop the pan or change the filter, just a standard flush with Motorcraft ATF. Takes them all of 15 minutes.

 

[Funmart6]

That would be consistent with what most dealerships are doing these days. They don't bother to drop the pan or change the filter, just a standard flush with Motorcraft ATF. Takes them all of 15 minutes.

And for me, that is just not good enough. So from now on, I will change the fluid and filter myself.