Coach wanders when Flat towing F-150 HELP!!!

[Rick McC]

Wife and I just purchased 2023 HR Vacationer 33C, 7.3L Gas, on F53 Chassis. Took our first trip of 175 miles one way.



Coach drives great without flat towing my 2013 F-150 with 192,000 miles on it.


When I tow the F-150, the Coach is all over the road, wandering left and right and I have to constantly correct the coach to keep it between the lines. After 175 miles, I was exhausted.


Before we left on trip I had the F-150 front-end checked and aligned to factory specs. My F-150 drives great; so I can't figure out the solution and need some help.


I'm using Blue Ox Tow system rated for 10,000 lbs...FYI the coach is rated to tow 8000 lbs...my F-150 weighs 6000,



The only solutions I can think of currently is to replace suspension parts if necessary, my shocks, struts, possibly coil and leaf springs, tie rod ends, ball joints....All my suspension components are original, probably way overdue for these items to be replaced, but would that fix the problem???...something with my F-150 is causing the Coach to wander excessively.....TY in advance for any advice you can give me....

[Steverino]

I'm sure others will chime in with more specific ideas, but I'd start with the basics (so as not to assume)...

If your tow bar has locking arms are they fully extended and locked in place?
Is everything else in the hitch / tow bar / base plate setup fully tight / torqued down?

Also, did you do your own install, or did a shop take care of it for you? If the latter, and since this is a fresh setup, why not take it back to them for evaluation?

Good luck - I'll be following with interest.

[weighit]

I was towing my Cadillac SRX behind a 34 ft Holiday Rambler Class A with the V-10. At first I was sure there was something I was doing wrong, wander all over the lane i was trying to stay in. Checked tire pressures, got weighed to set them, looked for anything worn or loose. Nothing found. It did drive totally better without that tow car hanging on the rear. Purchased and installed in the driveway a rear tracking bar. That fixed it, keeps the rear axle from ever so slightly sliding side to side causing the front to feel unsteady. In about 1 hour of work putting that bar into place fixed my tired arms and overall feeling of not liking that coach.
https://www.ebay.com/itm/31447916740...BoCi6MQAvD_BwE

[twinboat]

If the shop aligned your F150, the front end parts should be good, you can't aligne a front end with bad parts.

If the towing equipment seems in good shape, a rear track bar may be needed.

Get a friend to follow you while towing, to watch and film the truck, RV and tow bar while running down the highway.

Maybe that will give you an idea what's pushing you around back there.

[Shadow5501]

You have a couple of issues contributing.

First, your coach isn’t rated to tow 8,000lb. Towing capacity is the lesser of hitch rating or GCWR minus coach weight. Gross Combined Weight Rating is the total weight the manufacturer certifies for the chassis plus its tow. In your case, the coach can weigh up to 22k pounds and GCWR is 26k pounds. So a fully loaded coach can tow 4k pounds. To the extent the coach weights less than 22k rolling down the road, it can tow more than 4k pounds. But it’s unlikely you can tow more than 5k in a realistic scenario. Need to get the coach weighed in ready to travel state to determine its capability.

The second issue is that your coach has a short 208 inch wheelbase relative to its 34 foot length. There’s a lot of rear overhang behind the rear axle. This gives any mass on the back a very long lever with which to move the back of the coach around. This is compounded by towing a quite heavy Ford pickup.

As others have said you can probably get some improvement through aftermarket suspension upgrades, particularly on he rear suspension. But ultimately I think you’re gonna need a toad closer to 3k pounds than 6k to make it drive acceptably well.

[Rick McC]

Great questions, the answer is yes to all of the above questions. Thank you so much for the basics.

[l1v3fr33ord1]

Rick McC-

According to the specs for your coach:

GVWR (Gross Vehicle Weight Rating): 22,000 pounds
GCWR (Gross Combined Weight Rating): 26,000 pounds
Hitch Rating: 8,000 pounds

Please confirm these values for yourself, by reading them off the label inside the coach.

Here is the rule on flat towing:
The maximum flat tow weight is the lesser of (GCWR - Coach Weight) or the Hitch Rating.

Until you weigh your coach in its loaded condition you can't make the first calculation. If you did load your coach to the GVWR, then

GCWR - GVWR = 26,000 - 22,000 = 4,000 pounds

In that condition, your truck exceeds the maximum horizontal tow weight by 2,000 pounds.

It's fair to speculate that a toad weighing 3,000 to 3,500 pounds or less would give you less trouble. I wonder if someone would loan you a lighter toad for a test?

That said, if you keep the truck and load your coach so its weight does not exceed 20,000 pounds (to stay within the ratings), and have performed the "cheaper fixes," i.e.

- Set tire pressures according to the placard by the driver's seat
- Observe truck and towbar from the coach's rear window while underway
- Correct alignment on the coach front end, including "extra" caster if appropriate
- Add "quiet hitch" clamp(s) to take the play out of the hitch connection(s)

then adding a rear track bar, as others have suggested, is the next step, in my opinion.

[edit]I see "Shadow5501" addressed the weight issue while I was typing my message.[/edit]

[Rob_M]

Make sure that you get all the slop out of the hitch connections as that can let the towed wander back-and-forth. My coach is actually more stable with a towed behind it then without. I flat tow a 7000 pound 4wd Excursion.

When flat towing the weight of the towed vehicle should have very little effect on how the rig handles. There is almost no tongue weight and if the brakes are set up properly you should have no problem stopping it. The only issues you may have is climbing mountains.

[Rick McC]

Thank you so much that’s a great suggestion

[Rob_M]

AUTMATCH Hitch Tightener Anti-Rattle Clamp, Heavy Duty Hitch Stabilizer for 1.25 and 2 inch Trailer Hitches, Rubber Isolator and Anti-Rust Double Coating Protective, Black & Red https://a.co/d/hZjUu6y

[l1v3fr33ord1]

etrailer also carries a selection of

Towing Anti-rattle Hitch Clamps

There's at least one recent iRV2 thread on these, also.

[Isaac-1]

I am in the too heavy of TOAD camp, we have 2 TOADs a 4300 pound Jeep Cherokee, and a 2300 pound Toyota Yaris. When towing the Yaris I need to have the rear view camera on to know it is still back there, when towing the Cherokee it decreases my max comfortable driving speed by 5 or so mph as it constantly feels like the coach is trying to fish tail. Of course our coach is on a Workhorse P32 chassis not the Ford F53 so completely different suspension setup.

[Rick McC]

good sugestion..ty

[Dutch Star Don]

Too much toad weight......too short of a wheelbase!

Someone said you're towing 8000 pounds, but that is not the weight of the F-150. You're more in the neighborhood of 5500 -6000 pounds, which is really pushing your weight limits.

The "pulling" of that heavy of a toad on the back of the motorhome can really change the steering dynamics. Even my 42K pound DP steers/feels differently without the toad. It's subtle and not like yours, but I can feel it.

The trac bar that everyone mentions runs an arm from the frame rail to the rear end (axle) of the coach. As you drive, the rear of your coach body is moving left to right as you drive. As it rebounds, the front end moves to compensate. This is all multiplied by a short wheelbase. Adding the trac bar locks the rear end so there is no more side to side movement, consequently reducing front-end movement. If you're handy, adding a trac bar is pretty simple.

You don't say if this is your first motorhome, but one of the things you can try is to not steer it like a car. Rather than try to constantly stay in the center of the lane just ahead of you, steer father out in the distance. Pick a spot father ahead, like 75-100 yards and "aim" for that spot. This will reduce wandering. Also try to lock an arm/elbow on an armrest and control the wheel versus a death grip with both arms off of the armrests.