Have an 02 F-350 4wd with automatic tranny, 289k miles,basically stock. I tow a 12k# 5er for weekend trips. We have to climb steep inclines with low speeds to get to our local campground. Several weekends ago, I noticed the tranny gauge on the dash climb into yellow and almost red, so I stopped and let cool down, then proceeded on. Same thing on return trip. So I had fluid flushed and filter changed, had been approx 18k miles since it was last done. Also added an extra cooler in front of the a/c condenser, largest one available at my local camper store (approx. 12" x 18") Did same trip last weekend, on trip going (which is longer grade, then return trip) temp. just started to rise (didn't move but just a fraction) as we topped the mountain. On return trip the temp did ok, however it seemed as if it was just about to start to rise as the fan clutch kicked in and started to run hard, as it does when temps are getting hot. All other gauges seem to be riding in the normal range. No tranny fluid pucked out or anything. Tranny temp does fine when driving without camper. Any ideas, suggestions??? Our air temps have been around 95-100 degrees, with very humid stale air. Thanks for your ideas/suggestions/input!

 

Replace the tiny cooler you just added and the stock air to oil cooler with a cooler from a 6.0L truck. That will take care of your problem.

The problem with adding the third cooler (that's what you did) is that it can add enough restriction that the cooler bypass can open and less ATF goes to the coolers. This will reduce the cooling to less than stock.

 

Car-Part.com--Used Auto Parts Market is your friend...look up the auto trans cooler for a 2003-2007 6.0 power truck. A shift kit/ valve body will also help but start with the cooler and go from there.

 

A 26-row 6.0 trans cooler worked wonders for my truck. Best thing you could ever do for your trans, best of all, it's a drop in mod that only requires you change the line size.

Ford Truck Enthusiasts Forums - View Single Post - 6.0 Trans Cooler ? 26 vs 31

 

First off, the factory gauge in your '02 truck is nothing more than an idiot light.

Without knowing what the temperatures actually were, it's hard to say if you actually have a problem or not.

If the torque converter clutch is applied and you're maintaining speed in 3rd/4th gear, the transmission fluid shouldn't get that hot. I see that you said "low speed" into the campground.

Having some way to manually apply the torque converter clutch may be a good option for you.

 

Slow speeds are going down the state maintained road(while climbing the mountain), speed limit is 35 mph and with camper you can maintain approx 20 - 25 mph and this is for approx a 4-5 mile stretch. Truck does maintain speed at all times I have never had a problem with the pulling, even when getting hot it still wants to pull, just sounds like a freight train under the hood with the fan blowing. After peaking the mountain and descending the temp. is not a problem, not even while traveling through campground. Thanks

 

Then your heat issue is due to the torque converter's fluid coupling creating excess heat. There's nothing you can do about it unless you have the torque converter clutch applied.

 

So the LARGER cooler isn't going too do me anygood??? Thanks

 

I have some excess heat issues, too....

Looks like a new 6.0 cooler is $272 from Rock Auto. I'm worried that a used one might have come from a truck with trans. problems and I don't want their shrapnel entering my transmission.

Is there no cheaper way to replace the smaller/old OEM cooler with something generic and large? I realize that if they are all zip-tie mounted, then that's not acceptable.

Thanks!

 

Yes, a larger cooler will help.

 

The long tru-cooler and the v-10 coolers are popular upgrades, www.car-part.com is a great resource for autoparts. A good idea would be to flush a gallon or two through the cooler prior to hooking it up.

 

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