Does your Truck and trailer sway???

[HBarlow]

Just a guess here... ... ... .



Sway might be induced by tire overinflation because the tire's contact patch with the pavement is reduced. This might reduce traction adhesion and allow the tire to slip side-to-side under certain conditions. We've probably all seen that when a tire is overinflated for the load it is carrying the weight is carried on the center section of the tire and the outside edges may be barely in contact with the pavement.



Harvey

 

[plongson]

Well it turns out that the trip that prompted me to start this thread, I had 70 psi instead of 80. My thought was that nex time I would try 80. I can't believe that 10 pounds could make that much differance in my problem. I think it all goes back to the "YAW" that I described. If you take the wheel at highway speed, and sea-saw it back and forth, the truck does not go right and then left but instead piviots back and forth on an invisible center axis somewhere behind the cab. It really feels strange. When the trailer is attached, it is really amplified. I think this is the root or source of the problem. I checked the track bar today and it is very solid with no flex (58k and some miles). Tighting the sh**it out of the anti-sway made a big improvement. I wonder if it is the aftermarket "E" rated Michilins... .

 

[QRTRHRS]

plongson,



Still have the stock shocks? At 58K your about due for some good Bilsteins or Rancho's.



How are you loading your truck bed? You want that to be pretty well balanced out without to much behind the axle.

 

[R-N-R]

Tongue weight & tire psi calculations?

With the truck and TT loaded for a weekend trip, my CAT scale weights are:



Steer Axle - 3940

Drive Axle - 4760

Trailer Axle - 6480

Gross Weight - 15180



Does anybody know the calculations to determine tongue weight %, and optimal tire psi?



TIA,

Bill

 

[lizzyhermit]

just more input

see sig. below for the specifics but I have 50# in the fronts, 70# in the rear (Michelin E range OEM tires) and 50# in the four TT tires.

weight dist. looks like

13280 total

3680 rear

3880 front

5720 on the TT axles

no stability problems. btw, I hold the speed to 60-70 mph

 

[Badunit]

I tow a 25' popup camper. Below 70mph it is pretty stable. Above that and any little gust seems to set it swaying. I barely feel it in the truck, though. I just bought a friction anti-sway bar for it, we'll see if that helps on the next trip.

 

[R-N-R]

Found this formula in an old thread, seems kind of low.

 

[Mschevey]

19.5" rims and tires

I have the 19. 5" rims and tires. There is almost NO flex in the sidewalls. Reduced sidewall and higher load range (G). This makes it feel like a sports car. I expected the ride to be very stiff but it didn't seen to affect that part much. What I did notice the most was the responsiveness when performing lane changes, etc.



Mike