should make a big diff when towing on trans temps

 

Before I did the conversion, my trans temps would get into the low 220's on hills and would stay in the low 200's on flats. After the upgrade, trans temps rarely see the 190's.

 

Agree, once done I've never gotten over 190F.

 

We did our first tow with the new oil cooler combination. We never topped 170 degrees, with an outside air temperature of 75, and a climb from 4500' to 5200'. The trip home will be a better test with a climb from 0 altitude over a 5200' pass.

 

 

I used the Dorman 918-216 aftermarket version in our Ex and it works great.
The 6.0 cooler uses 1/2" diameter tubing (OEM is 3/8") which reduces the cooler line pressure.
The lower line pressure allows use of a 3rd cooler and a filter, if desired, without exceeding the OEM line pressure and possibly opening the cooler line bypass valve.

 

That is an OEM oil cooler.

 

Update: Climbed from zero to 5200' altitude towing a 31' 5th wheel trailer today. Max transmission temperature hit 210 and held there. It took quite a while at 4000rpm, 45mph in 2nd gear to climb from 160 to 210. The hardest part of the climb was maybe a 10 mile climb. The outside air temperature at the top of the pass was about 55 degrees, so I'll need to pull over and let the trans temp cool down on a hot day. Normal temperature on flatland is now 160 degrees. 210 degrees is hotter then I had hoped for, but of course it is a big improvement over the stock transmission oil cooler that was not running through the radiator.

 

Adding a B&M 70274 Supercooler after the 6.0 cooler would drop those peak temps down another 20 deg or so.
It's ports are 1/2" NPT so I use an adapter fitting that takes it to 1/2" hose.

 

recommends against stacked coolers. Being he helped Engineer the 4R100 I tend to follow his advice.

@billybobofkf do you have the newer radiator with the transmission fluid running through it?

I found my temps drop quicker after adding the OTW cooler and removing the extra tube and fin. I however am not towing heavy like you are though.

 

Ford used stacked plate coolers as aux trans coolers, PS coolers and engine oil coolers.
Or was the recommendation against stacking coolers in front of another?
I added the B&M cooler above the other one.

 

Against stacking coolers, multiple coolers inline with each other.

My apologies on the wording.

 

Yes, I bought a OTW radiator on your recommendation. I'm running the fluid from the transmission into the radiator, from the radiator to the trans oil cooler and back to the transmission.

Also, I realized that I forgot to take my front license plate off. It is halfway blocking the hole where airflow runs through. If I take the license plate off, I'll have better airflow through the trans oil cooler, maybe up to twice the airflow,

I'm now considering building a little fan setup to set in that hole to speed up cool down if I have to pull over climbing a mountain.

We have another trip planned in July that will take us over two mountain passes, so there will be plenty of time to rethink this issue.

 

Mark Kovalsky doesn't recommend running multiple oil coolers in series due to the possibility of activating the low pressure bypass. I understand that you are running two coolers successfully, but I don't believe that I'm up for trying it.