Change or add transmission oil cooler?

[Anchorclanker]

My 08 Limited has the standard 5 row tranny cooler and it works pretty good. I am, however, planning a cross country camping trip that will include some "mountain climbing". I found a 7 row cooler that will swap into the existing mounts and will (I hope) increase the cooling ability. A couple of beers later I thought, "Why can't I just ADD the bigger cooler and have 12 rows?"

I'm wondering if this will work, knowing I'd have to come up with a hose to connect the two, without adverse affect on the radiator cooling?

Any insight would be appreciated.

 

[stamp11127]

I would let the transmission temps dictate what i do.
Are you planning on towing a camper?
What is it running at now?

 

[mjp2]

You'll not see temps drop below the transmission thermostat's preset temp. Have you ever had the temps climb on you?

It's worth plugging a monitor into the OBDII port to watch what's going on before throwing money and complexity at something that might not even be an issue.

 

[Anchorclanker]

I do have a Scan Guage II plugged into the OBD port. I'm towing a 25' travel trailer that weighes in at around 4k when loaded. CGVW is around 10k or so. Last summer I towed up to WV and saw temps climb to 210-220 on the longer/steeper grades. I'm running full synthetic and I pulled of to let it cool before finishing the climb. In my "shadetree" mind this idea should help but I'm asking for more learned opinions.

Thanks for the replies.
Dave.

 

[coolzzy]

I went from a stock 4 row cooler on a 2012 F150 to a 6 row cooler, so I increased cooling capacity by 50%, and I saw no difference in how hot the transmission got pulling a trailer in the mountains, nor in how quickly it cooled off. The 12+ expy uses the 7 row cooler, and pulling 6k+ pounds through the mountains I saw 210 on a long climb in 4th gear at 65mph (ecoboost, so rpms were comparatively low due to the boost being applied). The 5.4 will turn higher rpms so it could stay cooler because of the pump running faster or run hotter due to the torque converter being unlocked depending on load and speed. If your converter is unlocked, the transmission will build heat very quickly. Keep in mind even on the max tow rated F150 which uses the same transmission as your expy, it only uses a 4 row transmission cooler.

 

[Anchorclanker]

coolzzy. Thanks for the info. When towing I run with the OD off to keep the torque convertor locked. My 5.4 does run at higher RPM that's why I was wondering about radiator cooling. Pulling up I-77 from NC to VA is a long climb through Fancy Gap and that's where my temps went up. Based on your results I'm probably better off just replacing the stock cooler with the new bigger one.

 

[mjp2]

The Scangauge is the greatest little troubleshooting tool ever. Sounds like you're on the right path with this.

Along with a bigger cooler, an extra capacity transmission pan might help keep things from heating up as you'll have additional fluid circulating through the system and a little more surface area on the pan itself to dissipate some additional heat.

 

[coolzzy]

Does the 08 have a tow/haul mode? If so and if it's the 6r80 transmission, you can get a tune for the motor and trans from 5 star tuning that will lock out 6th gear when tow haul is engaged. The tune wakes up the motor as well by enhancing the electronic throttle for better response. It's around 500 bucks for the tuner and 3 tunes of your choice, I ran the 87 octane performance tow tune with ODLK.

 

[Anchorclanker]

The 08 has the 6r75 tranny. There is an OD on/off button on the shifter that locks up the converter when off it selected. Thats how I run it when towing. A tuner may be an option at some point but I'm going to try the larger cooler and the high capacity pan first. More fluid takes longer to heat up and costs less.

Thanks to all for the info & suggestions .

 

[rollinstone]

So far I've always towed my 3100 lb TT with the tow/haul engaged (same as OD off) and average about 10-12 mpg. Never use cruise control unless I know I've got a long flat straightaway. I watch the tach on climbs and rarely go above 2500 RPM. On a steep grade that'll keep me at a comfortable 45 mph in the far right lane. YMMV, but I don't need to do 65 mph on grades.