Hi there

Has anyone updated their 6.0 to a 6.4 transmission cooler.

My transmission cooling system seems to be functioning fine but I have a slide in camper on the truck and 35 inch tires and run too hot at times.

Empty in the summer months I am fine but on the steepest of long climbs even when I am on the throttle provided I put it in tow haul.

The camper seems to make quite a difference though even in the winter.

If I drive it carefully I can stay below 220 on almost all long hills in the winter but will see 250 degrees when it warms up in the summer and don't want to keep having to change fluid that gets too warm. Everything seems to be shifting fine and it has only spiked a couple times above 250 degrees.

I wanted to try a 6.4 cooler in the hopes that will help enough.

Since I have to drop the pan to flush it out I thought I would upgrade to the 6.4 pan then too mainly for the improved filter for that set up.

How much extra work is it to fit the 6.4 cooler in there and what is needed for different fittings?

Thanks in advanced for any information.

Gary

 

The pan alone might be all you need. I tow a 22k 5th wheel at times in the desert heat and I don't think I've ever seen temps close to those numbers.

You may want to check the temp sender thermistor for accuracy, or your current cooler for flow issues (to include the toilet paper roll) filter if applicable.

I am geared at 4.56's with 37" tires, so there may also be an issue if you're still running 3.73's with 35's....but I don't think so.

I'm sure others will chime in soon.

• Normal Range: 170°F – 225°F is standard for the 5R110W.
  

 

I remember very erratic TFT readings during as it came up in temp while driving

in my case I want to say cold soak numbers were ok but it’s been awhile since

 

Mine runs 168* unloaded at all times. All I've done is added the 6.4 pan & filter. I've never seen it hit 200, even with the heaviest loads I pull. My EOT forces me to back off the throttle way before Trans temp does. Just out of curiosity, what are your EOT/ECT temps & what are you monitoring data with?

 

Pretty much my experience. Mine will run 160F most of the time. Pulling long hills with a trailer, ECT up in the 200s/210s the TFT will creep up into the 170s and maybe 180s. Towing the trailer on slow dirt roads getting to campsites I've seen 190F.

Stock cooler setup (radiator cooler & auxiliary air cooler) with the 6.4 pan & filter. The stock 6.0 trans cooling system is very over-built.

You've definitely got an issue somewhere. It almost seems like the cooler line might be plugged, or thermostat stuck closed or something.

Not sure if the 6.4 even got an upgrade on the cooler. It's basically the same transmission.

 

When I had my last 7.3, I swapped to the 6.0 trams cooler & saw my towing temps drop from 225 to 175. It is very effective.

 

Same here, 6.4L pan and filter, with a TP filter still in place in the original housing. Towing high cube shipping containers or 15000#+ in 100* weather, running 34" mud tires, and the trans temp doesn't break 200*f. Both of those are a lot harder on the drivetrain than a truck bed camper, frontal area and weight wise. Empty I've done the I-70 Eisenhower Tunnel hill climb in Colorado at 80MPH and not seen it go higher than normal; TXDOT dropped Ranger Hill from a 6* to a 4* grade but it's still two miles long and I do it at 75mph no sweat no matter how hot it is.

I'm thinking deeper transmission issue that just a cooler, unless the cooler he has is blocked somehow.