Towing power

[eric Brogan]

Towing with my 2010 Limited 4x4 152K bought used last year. Trailer is a 27ft dry weight is 5600lb. Using Reese distribution hitch. Got that dialed in pretty nice no sway issues. On highway no problems towing at 70MPH. When I get into the mountains it feels like it has no power to climb. I had to down shift to First gear manually to keep speed steady to climb a 5% grade. I feel like it should not be struggling that much to climb hills. Even on moderate inclines on the highway need to down shift to lower gears to keep it going, while grandma passes me in her buick boat. Any suggestions into what may be the issue or is this just how it is.

 

[JExpedition07]

What is the total trailer weight? When’s the last time it was tuned up (Plugs, air filter) etc? What axle ratio? No it shouldn’t be shifting to 1st gear esp if you have 3.73s. Any check engine light? Sometimes this is the first symptom of a misfire or catalytic converters when under load like that.

 

[eric Brogan]

The max weight is 6800.It still struggled when it was empty and bringing the trailer back to the dealer before we loaded it up. Never had it that full I haven't travel with full tanks yet. I couldn't find what ratio I had I looked on the Diffs couldn't find any markings to say. No Check Engine lights. I changed the filter 5k ago haven't done the plugs yet planning on it before the camping again. I bought it used so not sure the last time the previous owner did a tune up.

 

[coolzzy]

Does it have factory brake controller? I know the 5.4L will struggle in the mountains if it doesn't have the 3.73 gears. I'd start with plugs and coil packs, air filter, etc. Use Motorcraft plugs, no danger of them breaking in your model year. My 10 F150 with that motor was a joy to pull with in the mountains, more so with a 5 star tune, lots of low end grunt and never turned more than 3500rpm with 6200 pounds of trailer behind it.

 

[Dr0idattack]

My 2013 with HD tow didn’t come with a 3.73 so I bet there’s a chance your 2010 might just have a 3.31.

 

[JExpedition07]

Axle code 16 on the sticker is the 3.73 axles. 3.73s are standard on all Expedition EL vehicles 07-14 and optional on the standard length.

 

[chuck s]

I'd get the truck checked out. Throwing parts at it probably won't help.

Just another "I don't have that problem" post follows:

I don't have that problem with either my '07 5.4V8 (3.73LS axles) nor my better towing '17 3.5EB (3.31 axles). You should expect a down shift on any grade and even in some headwinds. Towing several times a year across VA, PA and NY neither downshifts below 4th gear other than rarely. Rarely seen a grade where I need the far right truck lane. Granny Buicks (is that redundant?) don't fly me on the grades. Ya gotta expect some higher engine rpm (much higher with the 5.4). I have not seen a need for 93 Octane even though the 3.5EB puts out more documented power with that fuel. All my driving is with 87. Headed to Virginia Beach in the morning -- but it's flat here near the coast.

What grades are you needing 1st gear? Been over the Blue Ridge (up to 5000') with the camper several times and the gearbox never went that low unless I had to stop.

-- Chuck

 

[theoldwizard1]

3.73 axle is a MUST if you are towing anything over 6000 lbs !

 

[JExpedition07]

I can’t imagine even 3.31 axles on the 5.4L would require any serious downshifts on a good running engine. I tow my boat (granted it’s a lighter load) that is 2,800 pounds dry plus 1,100 pound steel roller trailer so figure a little over 4,000 pounds total in tow. When I go to launch I have to drive it over the I-190 South Bridge (steep grade) and my 2007 Expedition EL 5.4L with 3.73 axles barely feels the boat behind me. Never has dropped below 4th gear to maintain the speed limit wherever I’ve driven with it in tow. Spends most time in 6th gear.

Remember the 5.4L is a torquey engine, your 2010 trucks peak torque is at 3,500 RPM.....start rolling over 4 grand and you’re just gaining horsepower and losing torque. The fact that your truck is screaming up in the high revs isn’t a normal characteristic of this engine.