2003 7.3 Trans cooler
- Thread starter Top Notch
- Start date
No but I've heard you have to keep plenty of airflow to keep things cool and I'm not sure what speed that entails. I'm going to guess that doing a lot of driving under 10mph and you'd want to have an auxillary fan pulling air thru the coils like they do on off-road 4x4 builds (maybe these guys add yet another transmission radiator).
The V10 cooler is much larger than the 7.3. Back in the day (before 6 oh) that was the mod to do. Also for the guys in hot climates they put an aux cooler with a fan on it under the bed, guys with the big 5 th wheels loved that addition.
The weak link in those trannys was the torque converter, under power it would slip, grenade and send junk into the pan via the cooler path. A common mod was to splice in a spin-on mount on the frame into the return line from cooler to catch anything before it found its way to the pan. I did this too and replaced filter (filled with fresh fluid) at every oil change. After 30k I dropped the pan and was amazed at how clean the pan was. No dust on anything.
Also, raising the line pressure with the AODX accumulator valve helped with lock up so it wouldn't slip.
The weak link in those trannys was the torque converter, under power it would slip, grenade and send junk into the pan via the cooler path. A common mod was to splice in a spin-on mount on the frame into the return line from cooler to catch anything before it found its way to the pan. I did this too and replaced filter (filled with fresh fluid) at every oil change. After 30k I dropped the pan and was amazed at how clean the pan was. No dust on anything.
Also, raising the line pressure with the AODX accumulator valve helped with lock up so it wouldn't slip.
the 6.0 cooler is the WAY TO GO! i did this mod to my 7.3 when i had it and it dropped my trans temps considerably. I also added an inline filter (i think it was good to 5 microns) and changed that at every oil change also (cheap maint). I also had a billet tq and custom tuning for the engine and trans which helped increase line pressure. as far as cooling though, the 6.0 cooler in line with the radiator cooler is the way to go.
EDIT: to give perspective, i towed up a 8 percent grade at 10 mph for 3.5 miles with a four place enclosed behind it with 4 sleds and saw a max temp of 180 degrees. When towing up canyons at higher speeds (when the tc was locked in) i would barely get my trans temp gauge to register in the winter (started at 100 degrees).
EDIT: to give perspective, i towed up a 8 percent grade at 10 mph for 3.5 miles with a four place enclosed behind it with 4 sleds and saw a max temp of 180 degrees. When towing up canyons at higher speeds (when the tc was locked in) i would barely get my trans temp gauge to register in the winter (started at 100 degrees).
N
nickPSD
Active member
I have had 7.3 with the 4r100. You can either go with a 5r110 cooler, or go to a auto parts store and get the biggest trans cooler and mount that infront of your radiators. The auto parts store cooler is cheaper, and I never see over 180 towing a 34' landscaping trailer in 100 heat.
I put a Derale stacked plate with a fan on my 99. Works great.
