I have a 2013 F150, 5.0L

I have 2 trailers

1) 1975 trailer weighing 2100kgs
2) 1998 trailer weighing 1300kgs

At highway speeds, the heavier one does not give me a problem and shifts up to 6th and stays there till a hill comes. The lighter trailer, at the same speed, hunts between 5-6th gears.

Anyone know why this is happening?

 

Which one is taller?

Wind is harder to move than weight.

Our 3,000 lbs empty horse trailer pulls as hard as our 7,000 loaded camper. And the horse trailer doesn't pull any harder at 6,000 lbs than it does empty. But that thing just pulls like crap no matter what....

Lock out 6th if you can if it hunts.

 

Are you in Tow/haul? That would help.

Lock out 6th or try speeding up 5 mph. I typically run between 60 and 65 and don't have that problem.

 

I'd lock out 6th gear.


Tow/haul mode should help as well.

 

I had it in tow/haul.

Dropping my speed by about 2 mph, it stopped hunting and stayed in 6th. With the older trailer, I was doing higher speeds and it stayed in 6th.

 

Very true. I would get the same mileage in my '07 towing my 23' Sea Ray (6000lbs trailer weight) as I would towing my mom's 16' pontoon boat (guessing 1500lb trailered weight). It takes more to get the Sea Ray rolling, but once it's moving it is fairly aerodynamic. The pontoon is like pulling a parachute...lots of vertical, flat surfaces sitting way up high.

 

Try going a little faster. Sometimes it helps reduce the frequency of downshifts.

 

Then it won't upshift into 6th.

 

No upshift to 6th means no downshift to 5th.

I'd rather tow in 5th so it doesn't have to downshift on every little hill.

 

Your lighter trailer is obviously not as aerodynamic. My 8500 travel trailer pulls great at 60-65. If I try running 70, I have a hard time keeping it in 6th on flat ground. It's a huge parachute, and the faster you go, the more resistance you get. Your options are to run a little slower, lock out 6th, regear to a lower gear, or get a truck with more low end torque. Most trailer tires are only rated to 65 mph, making option 1 the smart choice.

 

I did option 1. One tap down on the cruise was all it took to get rid of the hunting.