passing cars pushing TT, but not big trucks?

[katoom400]

after previously towing my Outback 250RS with a Toyota Tundra. I have upgraded to a 2015 F250 crew cab, short bed.

I took the time to go to a level parking lot to get my Reese dual cam WDH setup to the new truck. I set the ball height adjusted the tilt to get the front fender numbers back to unloaded spec and loosened the adjusters to the cam arms drove figure 8's in the parking lot and tightened them back down.

my first pull I didn't really notice any pushing, but it was a short 1hr trip. my last trip was about 3hrs each way and I started to notice that passing carrs seemed to the push the trailer a bit, but not big trucks, I would see them coming and brace for it, but everything stayed straight.

I started to notice the trailer getting pushed and sure enough every time there was a regular car/suv passing...

Am I going insane? how could a car cause this, but not a Semi?

[katoom400]

all makes sense, I just never seemed to remember this feeling with my previous TV 1/2 ton Tundra. It's not a drastic feeling, but it's enough that my wife felt it enough to mention it....I wasn't going to say anything if she didn't...lol

[atreis]

I've never had sway, but have noticed the same thing as the OP - but in every case it's a result of the relative speed difference. The car/SUV is going much faster than me, while the semi is only going a little faster. (Or to put it another way, the relative speed difference between myself and the passing car has more of an affect than the size of the passing car, if that difference is great enough.)

[Frostbitte]

katoom400 wrote:
after previously towing my Outback 250RS with a Toyota Tundra. I have upgraded to a 2015 F250 crew cab, short bed.

I took the time to go to a level parking lot to get my Reese dual cam WDH setup to the new truck. I set the ball height adjusted the tilt to get the front fender numbers back to unloaded spec and loosened the adjusters to the cam arms drove figure 8's in the parking lot and tightened them back down.

my first pull I didn't really notice any pushing, but it was a short 1hr trip. my last trip was about 3hrs each way and I started to notice that passing carrs seemed to the push the trailer a bit, but not big trucks, I would see them coming and brace for it, but everything stayed straight.
I started to notice the trailer getting pushed and sure enough every time there was a regular car/suv passing...

Am I going insane? how could a car cause this, but not a Semi?

I notice this as well. Very rarely do I feel the big trucks. But I can "feel" the smaller cars on my rear and when they're passing. I don't sway or anything, but I certainly feel them if that makes any sense.
I have no paperwork to back it up but I believe it's due to the aerodynamics of both the small car and the truck/trailer and the air currents/vortices being created. Something about the smaller cars.

Frostbitte

[Grit_dog]

Just speed up. Problem solved! (Where do I collect the check?) lol

[katoom400]

my tongue weight is comparable to yours..~900lbs. I'm already using 1200lb bars

here are some pics.

[vortec22]

BarneyS wrote:
Leon,
He is using a Reese "Dual Cam" hitch that has built in sway control. It is one of the better ones out there.

OP,
I would suggest you get the truck and trailer lined up perfectly straight, get out and look very closely at the V where the bars sit on the cams. Make SURE each one is perfectly set up exactly in the middle of the V. You will have to really look closely to see it. If not adjust the cam arm length until they are. l
What you have sounds like the are not centered and are fighting each other to keep the trailer centered.
Barney

I think Leon was talking about a sway bar on the rear axle of the truck, not the anti-sway bar on the hitch/trailer.

[myredracer]

We tow a similar length and weight of TT with an F250 and also have a Reese DC WDH. Towed all last season without the cam arms installed but installed them for the first trip out this year. Night and day difference and don't know how I managed without the cam arms. No issues with sway now - small cars or semis. Can now comfortably drive with one hand on the wheel if I want to. There's no reason for your setup not to be working flawlessly.

The first thing to suspect, as mentioned, is are the cam lobes centered in the bars? Did you relocated the bars and cam arms to the same respective left and right sides as matched pairs? Cam lobes and the bar ends are not always aligned at first and eventually develop a set. Are the bars at the correct angle with the correct number of links? I would have driven the TT + TV for a few miles to let things settle before adjusting and then check again after maybe 100 miles or so. Is there any play in the hitch head/drawbar receiver?

Are you adjusting the cam arms with the TT and TV fully loaded as you would for a camping trip? If you adjusted the cam arms without being fully loaded up, the lobes may not be centered when you head out on a trip. I was talking to a fellow camper the other day who has a new F250. New/newer F250s have one less leaf spring than older F250s like ours. I would assume the rear of a new/newer F250 will sag more with higher TW and load in the truck bed. Maybe air bags or adding another leaf would help?

We run the Michelins on our truck at 80 psi and 65 psi on the trailer. I've found that it takes a few miles at 60-65 mph on a freeway for the tires to warm up to operating temp otherwise the handling doesn't feel right. I added Bilsteins to our F250 and installed shocks on our TT. Both have been a major improvement in handling.

It's important to have the correct weight transferred back onto the steer axle. Ford now says 1/2 of the weight is to be restored. Maybe a trip to a scale would help. Knowing all your weights is a good thing to know regardless. What is the actual tongue weight and what rating of spring bar? We have 1200 lb bars with around 950 lbs TW. Started out with 800 lb. bars and it was awful.

Otherwise, a couple of photos of the WDH setup and TT + TV might help. It would be nice to hear back once you have things all sorted out. BTW, an F250 is a wonderful towing machine...

[Texmac1011]

Dave5143 wrote:

fla-gypsy wrote:


While your Load range D TT tires should be at 65 psi I am certain the rear truck tires would be more. Most likely 80 psi. Please clarify. Also Ford does not recommend restoring all the weight back to the front axle. I beleive it is now 1/2 of the loaded/unloaded difference. It could be you are pushing to much weight back on the front and making it lighter on the back end than it needs to be.

I have a 2013 F250. I've heard this before but I can't find where Ford says this. Do you have a link or a user manual page number where it states this? I'm not sure I really need to put as much weight on the front axle as I currently am.

I have a 2012. Page 254 of my manual says 1/2 the difference.

[katoom400]

jerem0621 wrote:
My Dually got pushed around more by Minivans than anything...

I'm actually about 1/8-1/4 inch up in the front. also tire sticker says 65 psi...tires say they can go up to 80.

[jerem0621]

My Dually got pushed around more by Minivans than anything...

[Dave5143]

fla-gypsy wrote:


While your Load range D TT tires should be at 65 psi I am certain the rear truck tires would be more. Most likely 80 psi. Please clarify. Also Ford does not recommend restoring all the weight back to the front axle. I beleive it is now 1/2 of the loaded/unloaded difference. It could be you are pushing to much weight back on the front and making it lighter on the back end than it needs to be.

I have a 2013 F250. I've heard this before but I can't find where Ford says this. Do you have a link or a user manual page number where it states this? I'm not sure I really need to put as much weight on the front axle as I currently am.

[CampingN_C_]

I posted about this years ago. I think it's a combo of a ton of different forces in play that we'll never really understand.
When I was towing with a Suburban it seemed nothing ever pushed me, now a Honda Civic can. I get more from a small Uhaul or UPS truck than I do a large bus or semi.
You're not crazy, everyones rig is different.

[Bendder]

I noticed the same thing with our Cougar 329TSB behind our F150 For sure it is a big sailand we have the 5.5 foot bed so with the generic WDH from UltraFab and 2 friction sway bars everything pushed us around n ccomeing up on the rear of the trailer but cars were worse than both minivans/SUV`s and the semi`s were the least of the worries. When a passing vehicle got up to the front of the the TV the only thing that would push us were large MH or semi's (the bow wave effect hitting our nose) but it was minimal at best.

Once we switched to our PullRite hitch which pivots 4 inches behind the diff cover we have no more sway period from anything and no sway control needed. The only thing wenotice now is the same bow wave comeing off semi's that will push the front of our TV its minimal so not a concern.

Always wondered why it felt this way. Never felt it with any trailer that I pulled before but then again they were all under 25' I think it is mostly from the rear overhang being so long rear of the wheels but that just my oppinion

[katoom400]

Dog Folks wrote:

kvangil wrote:
Could be the speed difference between you and the smaller car? I've noticed at times that a smaller car going much faster than me would push me a bit more than a semi that is slowly passing me by. Just a thought....

X2 We noticed the same thing.

The speed of the passing vehicle makes more difference than the size.
The faster the vehicle passing us is going, then the greater speed differential between us and the passing vehicle and thus the greater the "Push," regardless of vehicle size.

Although with our Dual Cam, we get very little "push" to start with.

this could be the case, but I don't seem to remember this with the tundra...although it had a longer wheelbase.