How I resolved a "towing instability problem"...

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Old 09-14-2018, 12:59 PM
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How I resolved a "towing instability problem"...

All,
My alternate title was "What a long, strange trip it's been," but clarity is warranted for helping others. First, in my own defense, I've been towing bumper-pulls for decades, so not a noob. Second, I've owned the travel trailer at the center of this since 2013, originally towing it with DadVan, a 2003 E350 12-passenger.

Love that van! V-10 towed like a dream, but at ~230K I felt it was time to "demote" him to daily driver, and buy a new tow vehicle. So I did. That's how my 2016 F250, the BAT ("B" is for BIG, "T" is for Truck, you can figure the "A" out) entered the equation.

I've owned numerous pickups (all Fords, of course), so even though new, it was like driving an old friend. At first, all was right with the world, then I added the cap you see in the picture, and it kinda went downhill. How badly downhill? I couldn't tow above 55mph without constant attention and correction! I was exhausted after 15 minutes, even at 56mph. I needed that cap, as I needed to carry the same "stuff" in the BAT that I carried in DadVan, so removal wasn't an option. I'll keep the list brief, but I tried everything I'd learned in those decades of towing, including (but not limited to) changing out the entire WD hitch system, buying my very own tongue-weight scale, numerous trips to a nearby CAT scale, reloading trailer contents, completely unloading trailer, variations of trailer/truck tire pressure (within reason), etc., etc.. Suffice to say I spent a fair amout of time (and money) trying to solve the issue, and lost a lot of time we could've been enjoying the trailer. Honestly, only one avenue was left, and some of you see it coming, aerodynamics. Two factors of note here, that trailer's back is totally flat, and that pickup is more than a foot shorter than the van. Soooooo... I went at that aspect with the same reckless abandon (and open wallet) as the previous pathways. I bought an "Aeroplus" wind deflector (which necessitated a Rhino Rack roof rack for the cap) and "Airtab" fuel savers (no, I'm not shilling for any vendor, and I received no discount). Here's the pics, then my report out.


Drum roll, please... We took the truck/trailer for a short (~65 mile) test drive, AND IT TOWS AS IT SHOULD. Huzzah! I simply cannot overstate the difference these things have made. I gotta tell you that this was the end of the line, and that the trailer was going to be traded if this didn't do the trick. I can hold my wife's hand again (traffic, weather, and safety permitting, of course). BTW, the wind deflector is now officially the (get ready to groan) "BAT wing." 8^)
 
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Old 09-14-2018, 04:55 PM
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Originally Posted by DadVan
.... At first, all was right with the world, then I added the cap you see in the picture, and it kinda went downhill. How badly downhill? I couldn't tow above 55mph without constant attention and correction! I was exhausted after 15 minutes, even at 56mph. I needed that cap, as I needed to carry the same "stuff" in the BAT that I carried in DadVan, so removal wasn't an option. I'll keep the list brief, but I tried everything I'd learned in those decades of towing, including (but not limited to) changing out the entire WD hitch system, buying my very own tongue-weight scale, numerous trips to a nearby CAT scale, reloading trailer contents, completely unloading trailer, variations of trailer/truck tire pressure (within reason), etc., etc.. Suffice to say I spent a fair amount of time (and money) trying to solve the issue, and lost a lot of time we could've been enjoying the trailer. Honestly, only one avenue was left, and some of you see it coming, aerodynamics. Two factors of note here, that trailer's back is totally flat, and that pickup is more than a foot shorter than the van.....
Aerodynamics is important, but you didn't mention anything about the suspension of the tow vehicles or tongue weight numbers.
Your pickup with a shell was where I was headed until I decided to get an Excursion which is basically an F250 with a shell.
Our TH trailer is similar, but is taller with a flat back.
The tongue weight on the TH is way too much, but it tows very well.
I've been moving things around to get the tongue weight down to 1200 lbs or so from 1400 lbs on a 7k trailer.
Our Excursion did not come with a rear anti-roll bar and adding one made a huge difference in normal driving and towing.
Installing stronger rear leaf springs didn't improve handling, but it doesn't drop as much from the tongue weight now.
Is your truck a 4x4? On the Excursion forum the 4x4s sometimes have wander issues because the front end alignment caster is off a bit.
 
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Old 09-14-2018, 09:59 PM
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I would of never hung in there for all that. Good job.
 
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Old 09-14-2018, 11:22 PM
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The airtabs have been on my list as a future upgrade. I have a toy hauler so it's taller than the trailer the OP has. My trailer pulls fairly well unless I'm right at the GVWR with a full fresh water tank.
 
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Old 09-14-2018, 11:31 PM
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Originally Posted by HRTKD
.... I have a toy hauler so it's taller than the trailer the OP has. My trailer pulls fairly well unless I'm right at the GVWR with a full fresh water tank.
Where is your fresh water tank - behind, above, in front of the trailer axles?
Our TH starting at the front has a 30 gal gray, 30 gal black, 50 gal water, another 50 gal water over the axles, and a 40 gal gas.

 
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Old 09-14-2018, 11:38 PM
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I have a 120 gallon tank that is mostly over the axles. It extends in front of the front axle by about 3' and then behind the rear axle by a foot. I haven't measured it so these are guesstimates.
 
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Old 09-15-2018, 05:34 PM
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R&T Babitch et al, for good or ill (meaning it rides a wee bit rough for my wife ), the BAT is as heavy-duty an F-250 4x4 as generally available. Camper *and* snow-plow packages, gooseneck prep, etc. Humorously, the "quick" method used by many (including myself at times) to adjust a WD hitch, that of measuring the front-fender distance from the ground, is of little use with the BAT's suspension due to the delta hitched/unhitched being <1/4". The cap is a "stripped" fiberglass unit that added ~300# centered over the rear wheels, so tow-vehicle weight likely wasn't the issue (but I removed the ~200# from bed just to have that delta/data point). Although I like to, and often do, travel with a full fresh water tank (35 gallons), I tried it with all tanks drained for that data point. I varied the tounge-weight from 12% (trailer TOTALLY empty) to 14% (trailer fully loaded, water and all). I tested with/without the truck's antisway turned on. The trailer has one-year-old tires with even tread. I installed the CorrectTrack axle alignment system several years ago to address the (sadly common) misalignment from the factory. I could go on-and-on, and did as I tried "stuff' (being an IT guy, I created various spreadsheets tracking my efforts and the results), but suffice to say I came to the conclusion little was left *except* aerodynamics. Personally, I'm not sure I would've tried things in a different order, as aerodynamics has never been a *primary* concern before.
 
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Old 09-15-2018, 05:38 PM
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stufarmer et al, thank you for the compliment! I'm an IT guy, thus my life is "ones and zeros." That translates into a sometimes completely off-the-charts approach to these kinds of things. Research, questions, discussion, etc. To slightly paraphrase, "wisdom through many sources" has often provided "the fastest path to the best solution," and in this case it surly validated my troubleshooting steps.
 
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Old 09-15-2018, 05:46 PM
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HRTKD et al, I'm *very* leary of tack-on stuff, preferring to leave my trucks and trailers as stock as possible. You'll *NEVER* find anything on my trucks/trailers only for appearance sake, and especially not for "coolness." That being said, I will pick nice over trash when I have to add something. As to the Airtabs, I researched, asked truckers and RVers, etc.. The responses I got ran from "meh" to "WOW," but there were no "I regret it." Following the instructions appeared to be paramount to achieve the advertised benefits, thus I did. I'll report back on any gas-mileage improvement, but that was/is of secondary importance to me. Let's face it, when you tow a 27' RV with a 6.2L gas pickup, you know what you're getting into gas mileage wise! 8^)
 
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Old 09-15-2018, 09:16 PM
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DadVan, did you put the airtabs on the top of the RV also? For some reason, it had not occurred to me that they might go on the sides also.

Did you try towing with just the air wing and just the air tabs? Was there that much difference with both involved?

I'm an IT guy also. We usually have a very methodical way of arriving at a solution. I remind my guys "Don't let perfect be the enemy of the good." In the case of trailers, a little sway was too much for me.
 
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Old 09-16-2018, 07:08 AM
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HRTKD et al, Yup, the Airtabs are on both sides *and* across the roof. They're spaced the recommended 4" apart where possible. Supposedly I should place them in front of the wheelwells and other spots (think stuff on the roof), but not that far into implementation yet if ever. As to whether I've tried just the Airtabs or just the Aeroplus, I may test with just the former, but can no longer test without them. Having said that, the Aeroplus *really* (and I mean *REALLY) reduced the the bug splatter on the front of the trailer, so I empirically "know" it's doing something, even if it's only reducing washing and maintainance! However, that "lack of bug guts" would seem to be indicative of the airflow, in fact, being routed over the trailer rather than at it. Regarding "solutioning," whether IT or otherwise, I've learned that 80/20 applies to almost everything, but like you I'll try for at least 99/1 when I can.
 
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Old 09-16-2018, 09:10 AM
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How much did the airtabs run? Did you they come in one set amount or could you order based on linear feet to be covered?
 
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Old 09-16-2018, 11:38 AM
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Originally Posted by DadVan
R&T Babitch ...the BAT is as heavy-duty an F-250 4x4 as generally available. Camper *and* snow-plow packages, gooseneck prep, etc. ....
Never seen my name with a "t" in it before.
I'm usually over on the Excursion forum and from reading about 4x4 Excursions two of the wander issues people have is lack of a rear anti-roll bar and caster that is too light.
I've seem some very heavy duty trucks, box vans, buses, etc. that have rear anti-roll bars and it works very well on our 2wd keeping the rear end more under control.
Adding the weight of a trailer to a 4x4 Excursion seemed to accentuate steering wander issues when the caster was under 5 deg.

 
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Old 09-16-2018, 02:12 PM
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HRTKD et al, the Airtabs can be bought as a "kit" (that's what I did) or singly. I didn't use all that I bought, but figured I'd have a spare or two (or ten), as well as be able to address the misc. "stuff" if it seemed worth it. Google for them to get their pricing, would ya? I would feel more comfortable that way, as I don't want to sound like I'm selling 'em.
 
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Old 09-16-2018, 02:28 PM
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R&T Babich, no disrespect intended by the "T," I assure you. The forum sometimes has hideous lag when loading pages and/or auto-saving, and an extra character can sneak in on me. The BAT had the "Rear Stabilizer Bar" as part of the "Super Duty Camper Package, option 471," so I didn't need to go that route. I have brother-in-Christ at church that works at a Ford dealer/shop; he'd asked the chassis/suspension specialists about my isssssssssues, so I ended up having all that checked (although oddly enough, their original concerns were around the steering stabilizer, as they'd seen some earlier-than-expected failures). Based on your comments, I'll likely have the caster checked again when I rotate/rebalance the tires.
 


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