Which transmission cooler line is the feed line?

[DP96XLT]

Hey guys, 1996 XLT 4WD v6 4.0l Auto here and I am wondering which line on the radiator is the feed line and which line is the return line back to the transmission?

I am putting in a aux tranny cooler and I know that one goes in series after the radiator transmission cooler from the bottom fitting, but I just want to verify that the top fitting on the radiator is the feed from the transmission?

I want to put a Filtran 3 micron magnetic filter on the feed line before the transmission coolers, or should it not matter and should I just put in in line before the aux cooler after the cooler in the radiator?

Logically I would figure:

Option (A) Transmission -> Filter -> Radiator Cooler -> Aux Cooler -> Transmission

or:

Option (B) Transmission -> Radiator Cooler -> Filter -> Aux Cooler -> Transmission

or if the fit would be better:

Option (C) Transmission -> Radiator Cooler -> Aux Cooler -> Filter -> Transmission

So, input on which is the best option and which line is the feed and which is the return on the stock cooler in the radiator (top/bottom) would be greatly appreciated.

 

[410Fortune]

confirmed
The top feed INTO the radiator is the fluid feed FROM the transmission

You can put the filter anywhere but I find the easiest place to plumb it is option C

 

[BrooklynBay]

It's better to attach the filter on the return line after the cooler before the fluid enters the transmission. This is the coolest part since the fluid cooled down after coming out of the cooler.

 

[Runnin'OnEmpty]

I want to put a Filtran 3 micron magnetic filter on the feed line before the transmission coolers,

Did you mean to state 30 micron filter?
A 3 micron would probably restrict flow,
unless set up as a bypass...

 

[imp]

confirmed
The top feed INTO the radiator is the fluid feed FROM the transmission

You can put the filter anywhere but I find the easiest place to plumb it is option C

Granted, heat transfer is SLIGHTLY affected by top or bottom entry into the radiator, and logic would dictate since HOT coolant enters the top, and lingers there, I think I would prefer entering hot trans fluid from the bottom, where it is cooler. The difference is actually pretty negligible; if you do not think so, IR contact measure both top and bottom radiator hoses. Their "Delta T" numbers will be found to be surprisingly close.

 

[BUXTER]

I would never put an Inline Filter in place of any Micron in that system beyond the Factory Filter in Pan - I don't believe in the PS Filters either - Cooled Fluid goes straight to Torque Converter so u really, really don;t wanna restrict that flow - Also in the Southeast IMO best to just DELETE the Tranny Radiator "cooler" - I have ran this setup on the 4r70w in my 96 MKVIII for 6 years no probs & a year in my 2001 Mounty 4r70w when I added a second Air to Fluid Cooler on driver side & deleted Rad Tranny fluid "cooler".

 

[410Fortune]

I have deleted the tiny fluid/fluid cooler inside the radiator and added a second factory air/fluid cooler a time or two. It works just fine. The fluid/fluid cooler inside the radiator is not very big and when they fail you mix water in your trans and destroy it (just a few drops of water in auto trans and the trans is doomed)

These little in line filters are not restricting any flow unless they get plugged up, but I hear you the factory pan filter does a great job if you change them out every 60-90K and use a good factory or better replacement

 

[BUXTER]

I drop Tranny Pan & Filter & 4.5 qts of Merc V every 30k miles - I have a couple “hertz” pans fm NAPA with drain plug so that helps.

 

[donalds]

I use this inline filter after the transmission cooler
I guess it comes down to what filter is being used

 

[BUXTER]

I use this inline filter after the transmission cooler
I guess it comes down to what filter is being used

Which will still restrict Cooler flow & even WORSE Kill ur Torque Converter as it starves for Fluid.

 

[410Fortune]

Dorman brand replacement pans also have drain plugs in them, a very nice feature

The inline filter will only cause restrictions in flow if they get plugged up, most people who are running a small in line filter are also aware it is there and change it often. I have not seen one cause flow issues on these transmissions..... have you? had one stave the converter for fluid?

 

[RickOTR]

This is what I use in mine, never had a problem. Just change it every 25K miles along with internal filter and fluid and you should be fine. I've always used Mobil 1 ATF Synthetic.

Genuine Ford Filter Assembly - Oil XC3Z-7B155-G | eBay

 

[DP96XLT]

The Magnafine filters are the same as the Filtran filters, as they both work down to 3 microns filtration, have magnets to trap ferrous material and have built in bypass valves that actuate at the inlet (thus if it *has* to bypass it won't allow crude from the filter to flow to the outlet) with a fairly large screen. The Filtran filters are also recommended by almost all OEMs from Ford, to GM, to Honda and Toyota as being useful in extending the life of just about any automatic transmission. You just have to change them every 30k miles, which is easy enough.

Point being, that unless you have a catastrophic failure you should be filtering "wear and tear" materials which will result in less "wear and tear". And even if you have a major failure, it will catch the really big and nasty stuff, but in that case you are screwed and replacing major components anyways, so I doubt a filter would cause it to be much worse.

In regards to power steering, considering the amount of garbage the "slipper design" pumps shed into the fluid I am most certainly going to run it on the return line. In fact it is already installed, I will post up pics when I am done with everything. I will be putting one in on my Mustang as well.

 

[DP96XLT]

Also, I will add that the transmission line "adapters" that are sold everywhere will NOT work with the Ford radiator/line fittings. Why ford ever decided to use a fitting where the first 1/4" is not threaded is just crazy, as well as the really deep fittings in the radiator.

I am going to replace the lower radiator adapter fitting with a 1/4" NPT x 3/8" hose barb brass fitting I have on hand and then just put a hose on the end of the factory line, then tape and seal the factory fitting to prevent it from corroding. What a PITA for something that should have been an easy matter of putting barb fittings on both ends.

 

[donalds]

Mine wasn't clogged after a year and I've been really use the transmission