Will another auxiliary cooler increase line pressure and slow the ATF flow?

BWSwede · Jul 6, 2014

I have posted this question on another forum but I thought I would post it here too to get additional feedback from non-Ford guys.

I have been searching the net and the archives and have not found what I am looking for.

I have a 1997 F350 diesel 4wd with the standard transmission coolers in the radiator and in front of the radiator. I need a more cooling when pulling my trailer in order to make it up the huge hill to my house without over heating the ATF. I am thinking about installing another cooler with integral fan below the body somewhere. I am also thinking about installing it after the stock air to oil cooler in front of the radiator and before it returns to the rear of the transmission.

A question I have,which I have not been able to find an answer is:

Will the line pressure increase from adding another cooler in series with the stock plumbing decrease my ATF flow to the point that I run the risk of damaging my transmission? (FYI: I have also installed a Magnifine filter between the transmission and the radiator.)

TIA,
BWSwede

JJZ 109 · Jul 6, 2014

Post here Blane: Ford Diesels - Diesel Forum - TheDieselStop.com
One of the regular posters there is a guy name Mark Kovalsky. He was a transmission engineer for Ford for many years and has answered a lot of questions for guys.

George2615 · Jul 6, 2014

Since you already have a second trans cooler in front of the radiator why not add a fan to that for additional cooling.
If you do choose to add a third cooler I doubt it would increase your line pressure that much. You would have to add additional fluid for the increased capacity.
What temperature is your trans reaching now when towing the trailer?

boggen · Jul 6, 2014

when placing stuff in series as you noted, it would add extra pressure, the pump would need to over come. how much actual pressure, and over all decrease in GPM (gallons per minute) the pump would work at, way to many variables.

larger hoses / pipes (inside diameters of them) = less extra pressure
vs
smaller hoses / pipes (insde diameters of them) = more extra pressure.

with you adding a filter, plus wanting to add another radiator. the pressure the pump has to over come will increase, as a result your GPM will decrease. how much not a clue.

suggestion is back off on MPH, shift to lower gear. and take the hills slower.
also how do you know transmission is over heating? have you actually installed a temp gauge for the transmission cooling system?

F3506 · Jul 6, 2014

Sounds like you'd be better off swapping the auxiliary cooler for a larger one.

The other option would be to look into adding a switch where you can manually lock the torque converter in a low gear. Just don't forget to unlock it as you take your foot off the skinny pedal or the engine will stall.

BWSwede · Jul 6, 2014

Thanks for all the replies guys.

Mark replied on the Ford Forum with some good information.

I could add a fan to the cooler in front of the radiator. Something for me to consider.

When I am heating up I can only achieve about 10 miles an hour. I try to keep the rpms at 2000 since that is max torque. I am in first gear.

I have an aftermarket VDO transmission temperature gauge stuck into the test port. I read 240 yesterday for the last 1/2 mile on the hill to my house. In case anybody is wondering I am pulling a 14k flatbed loaded with 13,900 pounds on the trailer axles as measured on the highway scales.

I didn't know a switch could be added to lock the torque converter in low gear. That sounds like a great solution. How does one go about doing that?

Thanks again for all the replies!

Blane

George2615 · Jul 6, 2014

Every transmission site you go to has a different answer about what the ideal automatic trans temp should be. Some say 212-300 degrees is normal, some say 180-260, while another says it should be under 250. Since you are running 240 degrees putting a fan in front of your aux. trans cooler as I mentioned before (and Mark from the Ford forum) should bring your temps down 15-20 degrees lower.

Stimw · Jul 6, 2014

Why do you feel you need a filter in the oil cooling circuit?
That would cause more restrictions than another cooler.
The stock trans filter should be more than adequate and I'm sure there must be HD filters in the after market.

F3506 · Jul 6, 2014

Here's a link for a lock up on a 4R100, but it states not to lock up in 1st gear since there isn't enough flow of the fluid to properly lubricate in first gear with it locked. Since the E40D is basically the same transmission, I wouldn't lock it up in 1st gear either.

Welcome to guzzle's TC Lockup Mod Web Page

BWSwede · Jul 6, 2014

Thanks for taking the time to reply to my questions/concerns.

I could add a fan to my existing cooler, I would rather have a passive system if possible so I may try the 6.0 cooler to see if that works without a fan. If it does I'll be done, if not, I'll add a fan.

Regarding the use of a filter...I just had my transmission rebuilt and there was metal fuzz everywhere in the transmission, in all the lines, and in the cooler. I also had debris from the clutches in the cooler. The filter in the transmission as I understand it is nothing more than a screen. Whatever it is it did not catch the debris I had floating around. When I saw other manufacturers had filters in the coolant lines I thought it would be cheap insurance to add one. If this is a bad move someone please let me know and why.

Good to know about not locking up first gear as that is what I would have tried to do.

Thanks again.