2003 5.4L - Transmission cooler + other upgrades for towing?

[Eric M]

Never having towed anything greater than a 4x8 utility trailer, I wanted to make sure I had all my bases covered before towing a travel trailer (3000-3500 lbs.) with my 2003 expy.

I have the 4R70W transmission. I'm guessing a transmission cooler would be a good idea? If so, any recommendations?

Also, are there other towing related add-ons that I should consider?

Thanks!

 

[Aspen03]

Does your 03 have the HD tow package? If so, it'll already be equipped with a cooler.

 

[Eric M]

Thanks for the info. It is an Eddie Bauer and has a factory tow package with all of the electrical hook ups. I guess that is the HD package?

 

[Aspen03]

If it has HD tow you'll see the 7 pin round connector just above the 4 pin, should also be able to locate the transmission cooler pretty easily as well.

 

[Hamfisted]

Do you know if the travel trailer has brakes on it ? Make sure your Expy brakes are in good shape as well.

If the trailer has electric master cylinder brakes, you can add a brake controller to the Expy very easy. The brake controller plug is right there by the OBDII port under the driver's dash, about where your right knee would be. It's plug in play with most Hayes, or other aftermarket controllers.


Brake controller plug by OBDII port....






Hayes brake controller installed ....

 

[David E]

Mine came with the 4 pin connector and a "regular" size tranny cooler. I upgraded the cooler to a larger one (I believe the one comes in the HD package) and plan to install the 7 pin along with the brake controller for my 3200lbs camper. Was also planning to upgrade the radiator to the bigger one but I believe that would require new pipes (bit of a deterrent) so might not do that.
To my best understanding the wiring is mostly there just a bit or work and it should be done. (did the same for my Minivan which had no setup at all and was a lot more complicated.)

 

[Eric M]

If it has HD tow you'll see the 7 pin round connector just above the 4 pin, should also be able to locate the transmission cooler pretty easily as well.

Got it. Thanks again!

 

[Eric M]

Do you know if the travel trailer has brakes on it ? Make sure your Expy brakes are in good shape as well.

Will do. Thanks!

 

[Eric M]

Mine came with the 4 pin connector and a "regular" size tranny cooler. I upgraded the cooler to a larger one (I believe the one comes in the HD package) and plan to install the 7 pin along with the brake controller for my 3200lbs camper. Was also planning to upgrade the radiator to the bigger one but I believe that would require new pipes (bit of a deterrent) so might not do that.
To my best understanding the wiring is mostly there just a bit or work and it should be done. (did the same for my Minivan which had no setup at all and was a lot more complicated.)

Very helpful. Much appreciated.

 

[BlackCoffee]

The 2003 Eddie Bauer has a connector just above the gas pedal to hook up a brake controller. My EB Bauer came with the Towing Package so the 7 pin connector at the hitch was installed. As for the connectors, I am not sure, but I would think they are part of your harness. I don't think they had different harnesses, just the connector and transmission cooler.

 

[Frank Swygert]

A 3500# trailer won't hurt a standard Expedition. A 4.6L standard model (not HD towing equipped) is rated at 5000#. The 5.4L is rated at more. You will need to add a brake controller and 7 pin trailer connector, but that's not hard to do. Will require running a couple power wires from the battery, one for controller, one for trailer connector.

My 06 with the HD package is rated to tow 8200# (4x4 -- 8400# RWD models). Now that isn't the weight of the trailer, but the trailer AND any load in the trailer and vehicle. My wife and I combined are 370-380, 45 for the dog. So that takes 415-425 off right away. 100# or so of luggage, down to 7600-7700. Another 300-400# of stuff in camper, so I'm maxed out 7200# for the trailer... and I have a 7200# trailer! It tows it ok. Just went to the mountains in NC (from mid SC) for the first time. Up the Saluda grade on I-40 it dropped down to about 45 mph up the hill, but stayed in 3rd gear. Coming out of Franklin NC it dropped down to 35 mph pulling up a very long 6% grade (a couple miles!). That was the longest and steepest hill. On shorter grades it only dropped to about 50 mph. If I were routinely traveling in the mountains I'd want more truck or less camper, but once a year at most I'm fine. I may upgrade the trans cooler though.

 

[BlackCoffee]

This might help you find the connectors on the harness. The brake controller is C2142 near where the ODBII connector is mounted. The 7-pin Trailer connector comes out of the harness next to the 4-pin and is C4099 .

 

[DLK726]

Would this brake connector diagram apply to a 2001 Expy?

 

[Hamfisted]

Would this brake connector diagram apply to a 2001 Expy?

Yes, look up under the dash near the OBDII port. Do you see the grey female plug there by it ? That's the brake controller plug.

 

[Grizguy]

If you only pulling 3500 pounds.. I don't think you will have any issue with any expy. Well.. maybe.. I had a 2005 expy with 250,000 plus miles. I bought it used in Florida with 150,000 miles.. I think pretty hard life. I drove it home to N W PA 80.. 85 MPH then with 225K + miles drove it to florida and back maybe a little faster than I should have More than 85... 90.. maybe a little faster.. Don't want to make people think I drive too fast.. After that trip, it did not like pulling a trailer any more. I was not pulling a trailer that fast..