I thought about adding a 3rd trans cooler on my truck. i have the stock one in my radiator, and an aux. in front of it and would like to put the 3rd cooler underneath the truck somewhere.(ive got a spare cooler)planning on towing about 8000 lbs with my truck.
can this hurt ,is this worth while or am i peein in the wind?


1990 f350 4x4 460 e4od trans 3:55 gears 9600lb tow rating

 

What are your temps running now ? If you are approaching the 200 degree F area, while towing heavy in the heat of summer, I would say installing a third cooler may help. I have never seen temps over 185 degree F even in extreme heat, towing at max. weight. I run a factory oil to air, and a aux. Hayden 679 oil to air. If you are breaking the 200 mark with the set up you have now, you might have clogged coolers.

Mark

 

My 94 460 has the factory aux cooler and the tank cooler. I tow over 8,000# and the tranny shop told me several years back that the factory cooler for this truck was more than adequate. That shop and one I used back in the 70's told me you can have too much cooling. I believe this is true especially for the computer controlled trannies since I am pretty sure they all have a temperature sensor that increases shift RPM when cold.

So unless your tranny is overheating, I wouldn't put in another cooler.

A third cooler is also increasing potential leak points by at least 50%, and mounting under the truck really raises you chance of ripping out the whole system on a snag or picking up a nice fat rock. If you need more cooling I would go with a bigger cooler or at least mount the 3rd cooler high and make sure all connections are solid.

Good Luck,

Jim Henderson

 

Mounting a trans cooler under the truck is unwise. The best place is still directly in front of the radiator. Otherwise, it can decrease cooling ability by more than 50%. You can have too much cooling. Mounting a third cooler wouldn't do you any good.

 

thanks to all who replied , at this point im trying to get my truck set up for towing a bigger trailer. i dont have a trans temp gauge so i dont know how hot the fluid gets. it sounds to me like you guys think i wont have a problem.i just bought this truck & im trying to make it as reliable as possible. none of us need a breakdown far from home. is a trans temp gauge a nessesity or shuold i just take it easy while towing?
thanks steve

 

Install a trans temp gauge before installing a 3rd cooler. With the gauge you will know the temp and can make a informed choice of any changes you need.

 

I am using 3 coolers on a 77 highboy 460 c6 4.10 and 33" tires . when pulling my 31' TT I have seen temps of 210 on verry long pulls my temp sender is mounted in the side of the trans. near the shift linkage. 2 years now and cold weather does not seem to be a problem , if it was a person could slide a piece of cardboard in to block some of the air flow.

 

instead of two or three coolers get one big cooler like the one that comes on the 03 super dutys or the tru-cool 4739 the specs are 40,000lbs 45,000BTU's 8 1/2"X23 3/4"X1 1/4" and those are the same coolers

 

thanks to all for the input on this. i think im gonna install a gauge and see what the temp is, and go from there. steve

 

Towing with an auto is always a sticky proposition in High temps. Knowing when to back out of it and let it cool down is worth as much as more coolers. More coolers can mean more pressure loss, which can lead to trans failure. If I had to do it I would pick that big cooler listed above and a trans pressure guage. Then when the tranny gets hot, back out of it or pull over and let it cool. I don't know how much truth there is too it, but I was taught that to cool one off you should put it in neutral and rev the engine to about 1500-2k rpm. I was told that in neutral there is more fluid flow to the cooler and the engine rpm helps the mechanical fan pull more air. With an electric fan you will only have problems if you rev the engine. Most of them will overheat if you rev the engine and aren't moving.
I can tell you that I have pulled a lot of loads with auto's using the ways I was taught and I have never burned one up from towing. I've had torque converter failures on E4OD's but never burned one up.

Downshifting is also another area. When you hit a hill and lose speed, downshift it early and keep the rev's up. Many times the tranny won't shift itself until you get so slow that the next lower gear won't gain or hold the speed you have left. In my 79 that meant that when you hit 50-55 you pulled it out of drive into 2nd. When you hit 30 you pulled it into 1st and kept the hammer down. Same goes for downhills. Downshift early at the top and keep your speed low. If you wait till you're going 80 then try to slow down, you won't have enough brakes or tranny to slow it down. Especially on long downhill runs where you might go for 8-10 miles downhill.

Just my 2 cents. I'm sure there is some engineer who might read this and want to scream, but this is what I've always done and it has always worked for me.