transmission lines

[Mickey Bitsko]

Do all vehicle auto transmission return lines go in the top of the radiator?

 

[RonD]

Radiators for vehicles with automatics can have bottom trans cooler tanks(both lines at bottom), or side trans cooler tanks(one line at the top, one at the bottom), never seen one with trans cooler at the top, but no reason it couldn't be made that way.

 

[Mickey Bitsko]

I didn't explain myself, generally speaking, is the top radiator/trans cooler fitting always the upper fitting on the radiator and the bottom fitting radiator/trans cooler the return to the trans?

 

[RonD]

I would think they would be the same as the coolant hoses, top is IN lower is OUT, but do not know for sure.

 

[Mickey Bitsko]

I would think they would be the same as the coolant hoses, top is IN lower is OUT, but do not know for sure.

That makes sense, thats the way it is on the rangers, I have to figure out which line is which on my e4od. It does not go through the radiator , the lines go directly to an aux cooler.
I don't understand when people say , put the transmission out line through the radiator first, don't know how you can do that.
The out line HAS to go through aux cooler first, then through the radiator down the IN line to the trans?

 

[RonD]

Just me, but I install AUX trans cooler on the easiest line to use, never had a problem.

If trans fluid leaves transmission at 200degF travels thru rad first then AUX then back to trans at 150degF, it would be the same if AUX was before rad, temp drop is consistent to the coolers used not the order of the coolers.

Some say the rad can heat up the trans fluid, then you have a problem with engine over heating not trans cooler placement, lol.

 

[enjr44]

From a theoretical (engineering) point of view you would want the aux cooler after the cooler in the radiator. Hot fluid into rad cooler, cooler fluid into aux cooler, coolest fluid back into transmission.

From a practical point of view it probably makes very little difference!

 

[Mickey Bitsko]

The transmission rebuilder called me back , Their company does NOT recommend going through the radiator, in theory, if your transmission cooler is keeping the temperature @ say 170* then sending it through the rad that is 200* is counter productive.
I'm going to try some Lubeguard kooler clean, quite a number of local mechanics use all their products and the internet reviews are very good. So. what the hell, I'll start with that. The cooler that I have is a stacked cooler with 21 plates, should be good for hauling 30k lbs according to other manufacturers.
.

 

[ghunt81]

I believe the idea of sending it through the radiator serves both to warm up cold fluid, and to bring down the temperature of hot fluid before it goes through the auxiliary cooler.

 

[enjr44]

^^++

 

[RonD]

Yes, rad trans-cooler serves dual purpose, cooling the trans fluid and to warm up trans fluid in winter months.

Coolant coming into the rad is 200degF, at the bottom of the rad(or side for crossflow rads) there is a 20 to 30degF drop in temp, so trans-cooler would be 170-180deg with engine under a bit of a load, and under a load trans fluid would be 200degF +
So it would be cooled
And in the winter it would be warmed up faster, which is better for the trans.

 

[enjr44]

All I know for sure is that Uncle Ford installed my aux cooler after the Radiator's cooler. It goes from Trans to top of rad, out the bottom of the rad cooler, through aux cooler and then back to the transmission.