Best Method? - Install ATF Cooler, Filter and Change to Synthetic

[joshfig]

I know that this has been discussed at length, but I want to get clarification on one thing that I haven’t been able to get consensus on.

I am getting ready to add an ATF cooler and filter to my 2000 XLS 4x4 as well as converting to synthetic ATF (probably Mobile 1). It does not have a secondary cooler from the factory. It does have 63k miles and had an ATF flush at 35k miles.

My question is this: Is there any benefit to doing a drop pan fluid and filter change in addition to the flush? I don’t see any reason to go through the hassle, unless having that old filter would create problems.

The other question is: Will it be a problem going from Micron III to Mobile 1?

Any thoughts?

 

[bwinterroth]

Hi joshfig - I have a 2000 XLS as well. first of all you should drop the pan to replace the filter before doing a flush. There are several threads around here on this topic. Secondly, we do have secondary cooler which is found behind the grille in fron of the radiator. The coolant lines run from the tranny into the radiator, out of the radiator into the secondary tranny cooler, and back to the tranny. About three weeks ago, I dropped the pan, replaced the filter, bolted the pan back on with a new gasket, replaced the 4 quarts that came out during the pan drop with cheap Mercon V (since you are going to fluish it immediately after). To flush I used Rhett's method mentioned in one of the flush threads. Just search for it. I wouldn;t recommend using Mobil1 synthetic ATF as it isn't Mercon V compatible (even Mobil says it isn't). They will be coming out with a synthetic line that is compatible with Mercon V within the next few months but for now I wouldn't risk it. Either wait or use semi synthetic Mercon V for now. It should take about 15 quarts to completely flush out the tranny.

About 5 days ago I installed the secondary tranny filter from summit racing. I put it between the radiator line and the secondary tranny cooler. Have only put around 50 miles on it, but so far everything is running smoothly. The extra quart in the sytem also helps to cool the ATF. Good luck

 

[joshfig]

Factory Cooler

bwinterroth - Thanks for the reply. I don't think I have a factory cooler though. One difference with our X's is that I have an OHV. I think the cooler only came with the towing package. The return line (coming from the bottom of the radiator) goes directly back to the transmission. I am planning on cutting that and running 3/8'' fuel line to the cooler.

I purchased a Gen 1 ATF cooler that I am going to mount in front of the radiator.

Regarding the Mercon V. When I had it flushed 25k ago by a shop, I think they used Mercon III. Is that a problem?

 

[Tony H]

Another option regarding the Cooler is to just go aftermarket and don't run it through the radiator at all.
1. It makes future radiator changes a snap
2. you are not trying to cool the trani fluid in a radiator that is running a little under 180 degrees.

 

[bwinterroth]

Yea running Mercon III might be a problem in a tranny that needs Mercon V. I don't know why they filled it with Merocn II when the dipstick obviously says ONLY Mercon V. I would flush it out and replace with Mercon V. I use Castrol semi-synthetic. I don;t have a towing package on my XLS but yet I have asecondary cooler. Weird. Just stand in fromt of the car and look through the grill to the left side of the ford emblem. There should be a foot long cooler in front of the radiator. You can also life the black flap under the hood (where you gain access to change the healights). I just don't get why you wouldn't have one since my car didn't comw with a towing package either.

-Ben

 

[joshfig]

It's possible it does have a cooler. Where does the line come out of the radiator and into the secondary cooler? I assumed it came out of the bottom. If there is a line that comes out of the back of the radiator and directly into the cooler, then I may be wrong. From the bottom of the radiator, the return line goes straight back to the Radiator.

Regarding the Mercon III vs. V, I was incorret. The shop used Decron V (which I think is the same as Mercon V).

I have heard both ways on the pan drop, but it sounds like a safe bet to do the pan drop and filter change first. Then do the flush. Then hook into the new cooler and filter from the return line from the bottom of the radiator.

I'll stick with Mercon V for now.

 

[bwinterroth]

go under the pasanger side bumper area and look up. you should see two lines coming from the rear of the car. As the two metal hard line come up to the front one of them turns toward the driver side and enters the radiator (I think the top). This is the FROM tranny line. The other line (RETURN to tranny) you will see continues straight and is attached to 3/8" rubber tubing that bends up towards the hood. it should be connected to the auxillary cooler. Do you see it? If you do, then this is where you flush the tranny fluid. Follow the line that returns back to the tranny and where the rubber hose from the auxillary cooler meets the metal hard tubing back to the tranny. Remove the hose from the metal tubing and plug up the return hard line with a rubber cap. The removed rubber hose should still be connected to the auxillary cool and be dangling down. Hold a gallon milk container with quart increments written on it under the tube and ask a friend to start the car. Fluid will start to run into the gallon jug. When it reaches 1 quart stop the car and fill the tranny with 1 quart new fluid from the tranny filler under the hood. Run the car again until another quart is flushed out and replace with 1 quart fresh fluid. Since the old tranny fluid is warm and the new tranny fluid is colder, they will not mix. Repeat the 1 quart flush/fill for about 15 quarts or until the fluid is nice and clean red. Then take of the rubber cap and replace the rubber tubing onto the hard return line to the tranny. Clamp it and you are done!

 

[joshfig]

I think that is the setup I will have after I install the secondary cooler. Currently, I have a fixed line that comes out of the bottom and straight back to tranny. No 3/8'' rubber line that splits off and up to the cooler.

Thanks again for the insight.

On another note, you have a 2000 as well. Did you have any of the issues others have mentioned on this site getting your tranny pan off? It doesn't look like anything is in the way except for the cat (which I think has enough room).

 

[bwinterroth]

Yeah getting the pan off wasn't hard at all. It won't drop straight down, so you need to undo all of the bolts except for the sid closest to the front and let it hinge downward, letting most of it out. Then you can slide it out toward the drivers side and pull it down. Not hard at all. I did it by driving the front wheels onto the ramps - allows for easier access.

-Make sure you put new o rings on the new filter and make sure they sit into holes in the bottom of the tranny. This is important

-Ben