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.

 

[1997SCEBFEX]

++ on bigger pan. mine (Mag-Hytec) holds an additional 8 qts.

 

[Anchorclanker]

1997SCEBFEX. How much lower does your pan sit than the stock unit?

 

[coolzzy]

OD off and tow/haul are not the same. Tow/haul does not restrict the use of any gear, but it does adjust the shift rpm by holding gears longer before up shift, and aggressively downshifting on its own when acceleration is detected with no pedal input (rolling downhill). On the 6r80, 5th and 6th are overdrive gears, not sure on the 6r75.

 

[coolzzy]

A bigger pan can be a blessing and a curse. It does take longer to heat that extra fluid, but once it gets heated, it takes longer to cool as well. Since the cooling circuit is thermostatically controlled, you would be better served (especially financially and in ease of install) with just a larger cooler. These transmissions are very strong and failure is not a common thread, especially considering how many of them are on the road in other vehicles besides the expy.

 

[Anchorclanker]

Coolzzy. 5&6 are od on the 6r75 also. I run with overdrive on if its a flat road but otherwise od is off to avoid hunting on grades.

 

[Anchorclanker]

Update. I swapped out the cooler, 7 rows of fins instead of the original 5, which is a 40% increase over the stock unit. It reduced transmission fluid temp by roughly 7-9 degrees whie towing. It is enough make me feel more comfortable climbing the NC mountain roads. It's the Dorman 918-234 oil cooler and the only mod needed was to shorten the upper hose.

 

[ExplorerTom]

I swapped out the factory cooler on my 1st gen with a larger Hayden cooler. I watched trans temps still hit 200-215 in stop'n'go city driving in the summer with the AC on (maybe only 190-200 with AC off). It seemed that the cooler would get saturated because even driving highway speeds wouldn't cool it down.

Then I swapped the Hayden out for the BIG daddy cooler from a 6.0l diesel. Highest I've seen it since is about 185 while climbing a steep grade. But once I got passed that, it cools back down to about 150.

I know the transmissions are different, and I believe the 3rd gens are designed to run hotter, but I my opinion and experience, there is never such a thing as too much cooling for a transmission. The thermostats in the transmissions will regulate temp as needed- you just need to make sure there is plenty of cold fluid to send back in.

 

[chuck s]

Just a note from my personal towing with my (former) 2007 Expedition with HD Tow. YMMV.

I never locked out overdrive as the Interceptor gauge I mounted out of curiosity about transmission temps showed the transmission locked up immediately and securely in all gears, there was no transmission slip which is the culprit in many transmission overheating scenarios. Additionally since the transmission didn't "hunt" there was no need to lock out overdrive. Trailer is roughly 5000 pounds. Heavier trailer may be different.

I liked the Interceptor gauge and when towing I usually set it to indicate transmission temp and cylinder head temp. Transmission temp rarely exceeded 200°F, the "alarm" on the gauge was set at 220°F and only activated one (1) time in 10 years of towing and this was on a brutally hot day in city traffic. Only at that temp for a couple of minutes.

-- Chuck

 

[coolzzy]

I pulled my 29ft rv (6k pounds) up and over horshoe bend hill in Idaho this past weekend. It is a long 7-8% grade and I usually avoid it by taking back roads around. I had never pulled it with the new expy and will say she pulled like I was on flat ground. I went 65mph all the way up, passing semis and shocked diesel pickup drivers alike. Transmission temp was 206-208 on the climb, engine temp climbed a bit over normal by the time I hit the peak, I was in 4th gear for the climb except a short sting in 3rd when I had to pass a slow moving car.

I've pulled this hill with a 5.0 F150 (2012) and a 5.4 max tow F150 (2010 with 6speed). Both were labored but did the job, with the 5.4 beating out the 5.0 handily. Neither compared to the ecobeast expedition which managed the same task in silence and without any noticeable struggle. I think the stock cooling unit is more than adequate on these vehicles, although my 2012 F150 always ran hotter temps even with a larger cooler installed. Maybe some of these transmissions run hotter or have varying accuracy on their temp sensors....

 

[JExpedition07]

Coolzzy thanks for the feedback on your trip. The ecoboost likes to tow since it’s torque comes in early. I was under the impression the 5.0 was better at towing than the 5.4L as many 5.0 owners stated it was night and day. The torque curves speak a much different story with the 5.4L throwing more torque up to 4K rpm....curious if you ever ran E85 in the F-150 5.4, power was increased to 320hp/390 lb ft. on flex fuel. Curious if it makes much material difference in flex fuel capable 5.4 engines, MPGs surely take a hit on it. The 6 speed is thermostat controlled and it opens up to the cooler at a certain temp....as you stated could be set differently or accuracy of sensors.