Towing Stability

I have the Pro Pride 3 with weight distibrution and have taken all the measurements when towing. The loose or sway feeling was when riding with my family in the car, not towing. We probably had about 950 lbs of people in the car with a payload of 1650 lbs. I called the guy who installed the tires and he recommended when not towing to decrease the PSI to 50. That might help.

The reason I went with the ten ply tires is because my tongue weight with the hitch is 752 lbs for the trailer tongue weight and then 195 lbs for the hitch, so 947 lbs. I was getting a lot of side wall flexing with the original tires so I went with the 10 ply truck tires as recommended by a truck company (didn't purchase from them, just took the recommendation).

So as I was saying, the wdh is working properly, all measurements are in line, just experiencing the lack of stability which was more concerning since I wasn't towing. I am going to adjust the PSI when not towing and then go from there and get the vehicle looked at if it continues. Thanks for any help.

Easy to confirm your WDH is sending weight to the front axle by weighing the combination before and after the trailer the trailer goes on the ball. It may be good but you're running your tires extraordinarily over pressure -- not for the tires but for the Expedition. Because they're dramatically overinflated they're only contacting the pavement in a thin center section drastically reducing traction especially laterally. Like the sketch I just posted. Like running on bicycle tires.

Without the weight of the trailer the tires are much less loaded which magnifies the effect of over inflation as even less tire tread touches the road.

Compare the weight capacity of the truck tires at 80psi to the weight on the axles. I'm seeing 3515 pounds per tire at 80psi.

Front axle gross axle weight rating: 3,550 pounds. Pair of tires at max pressure: 7,030.
Rear axle gross axle weight rating: 4,300. Tires 7,030.

Or 14,060 pounds for the whole truck -- my Expedition has a maximum allowable weight of 7,500 pounds and yours will be similar. Empty the Expedition weighs about 6,000 pounds. Inflating the tires to handle over 14,000 pounds will make it ride like a truck and be squirrely due to so little rubber on the road.

-- Chuck

That makes sense. I took them down to 50 PSI today and it definitely was better.

If it calculates like a sraight ratio then 50 would seem correct. My numbers are 6890 at 80 on the rear axle and 4280 at 50 PSI.

This was very helpful. Thanks.

It is pretty linear. A Cooper chart I found indicates their LT tire rated to support 3415 pounds at 80psi will support 2660 pounds at 50psi or 5320 per axle or 10,640 for the truck -- which is 3,000 pounds more than the permissible GVWR of 7,500. Appears safe to me. Keep an eye on tire temperature until you have some experience with this pressure -- and the rest of the Tire Jury here votes.

-- Chuck

Do you happen to have a link to that chart?

Try this. <--- that's a link. The 3415 pound capacity at 80 psi shows at the far left making me think this is your tire.

And this: https://tirepressure.com/tire-pressure-calculator

Edited: When I ran the pressure calculator (above) against my OEM P-metrics and LT tires of the same size (higher load rating though) it says the appropriate pressure for the LT tire is 50 psi -- just like our guesses and the chart shows for the same capacity. 50psi will ride a lot less truck like.

-- Chuck

I have a 2017 XLT EL with heavy duty tow package. I’ve been towing our Grey Wolf 23MK for two seasons now. Fully loaded it’s about 7,600lbs. I use an Equalizer WDH 1,000/10,000 model. The first couple of tows were hot garbage. I could feel the OEM tires rolling under them selves on long sweeping turns on the highway along with the crappy weak sidewalls on the OEM trailer tires. I ordered a second set of rims and load range E tires, Helwig sway bars and sumo springs. I also quickly replaced the crappy new tires on the trailer with new Goodyear Endurance with a higher load range.

When ever I tow I air up the tires I air up the tires to 80psi. (When I’m not towing. I reduce the air to 55psi) I also check the torque on trunion bolts/nuts too. I come to find that they do loosen a smidge over time. Even though I use jam nuts and locking nut. I’ve also adjusted/fine tuned the hitch multiple times while fully loaded trying to maximize the hitch ability to control sway and distribute weight.

Over all with those mods and adjustments. And really being aware of how I load the trailer. Most of the time I also fill the water tank with 40 gallons of water. I’m sure some syphons through the over fill tube. Anyways My Expy tows damn good. We have towed through mountains, snow, heavy rains, heavy winds etc. I can easily and comfortably tow at 80mph. No white knuckle steer with one hand. The only times I have issues is during extreme windy days.

I also got rid of those crappy OEM mirrors and installed nice tow mirrors that retain OEM functions.

And who doesn’t like pics?

Larry McNeil said:

Hi again, guys. Ok I think I have the sway thing squared away. Went with LT tires and Helwig rear anti sway bar with new Helwig FRONT anti sway bushings. (That was their idea - even supplied the bushings)

NOW, I am contemplating a lengthy road trip - likely 7000 miles over the next 18 months. The Expi has 76000 on it. I HAVE done specified service at the dealer all along - flushes, etc included.

What I am after are community thoughts on other preventives or enhancements before I start out. My concerns are basically centered on an unease that I am driving basically a f-150 and towing a 6000 pound airstream for a long distance, and up and down mountains. It will be basically freeway, so no EXTREAM grades, but still …

As a reminder, the rig is a 2017 King Ranch 4 X 2 with the 9000 # HD towing package. I use the Equal-izer 9000 # hitch. Trailer tires have been upsized to 16” Michelin truck tires and I run them at 50 #.

It should be a reasonably relaxed trip - doing 300 - 500 miles a day with additional ‘stay overs’ as we feel inclined.

Thoughts? Equipment I might further invest in? Early replacements? I have put some thought into just doing the shocks as a proactive step, for example.

Click to expand...

How long has it been since you had the trailer bearings repacked and/or replaced? I do mine every 3years/15kmi. And it might not be a bad idea to have the trailer brakes inspected while they’re doing the bearings.
Also, trailer tires should be replaced every 6 years…

Rosspack said:

I have the Pro Pride 3 with weight distibrution and have taken all the measurements when towing. The loose or sway feeling was when riding with my family in the car, not towing. We probably had about 950 lbs of people in the car with a payload of 1650 lbs. I called the guy who installed the tires and he recommended when not towing to decrease the PSI to 50. That might help.

The reason I went with the ten ply tires is because my tongue weight with the hitch is 752 lbs for the trailer tongue weight and then 195 lbs for the hitch, so 947 lbs. I was getting a lot of side wall flexing with the original tires so I went with the 10 ply truck tires as recommended by a truck company (didn't purchase from them, just took the recommendation).

So as I was saying, the wdh is working properly, all measurements are in line, just experiencing the lack of stability which was more concerning since I wasn't towing. I am going to adjust the PSI when not towing and then go from there and get the vehicle looked at if it continues. Thanks for any help.

Click to expand...

Just reading this thread - you may have a payload issue when traveling. You said in post 31 above that you have 950 pounds of family and 947 pounds of trailer tongue weight and hitch - a total of 1897 pounds of potential payload. That is a bit more than your rated payload. So if the family total when towing is the same as you reported when you were seeing the sway, you need to rethink things.