Originally Posted by srg12
Does this sound about right?
Sounds like a good start.
But it's just a start. Next step is to load both tow vehicle (TV) and travel trailer (TT) with everything that will be in them when on the road to the campground. People, pets, tools, jacks, food, drinks, bed clothes and other linen, pots and pans, dishes, cultry, at least enough fresh water to flush the pottie when on the road, full propane tanks, 30-amp extension cord, water hose(s), wheel chocks, clothing, etc., etc. Then go to a truckstop that has a truck scale (or CAT scale), fill up with gas, and weigh the rig three times:
1] TV and TT with spring bars installed.
2] TV and TT without spring bars installed
3] TV with WD hitch head, but without the trailer
Compute hitch weight.
The weight on the front + rear TV axles with trailer but without the spring bars attached,
minus the weight on the front + rear TV axles without the trailer, but with the WD hitch head plugged into the receiver.
Compute gross trailer weight:
Trailer axle weight without spring bars
+ hitch weight
Compute hitch weight as a percentage of gross trailer weight.
Hitch weight divided by gross trailer weight.
Goal is 12% to 13%. More than 13% is okay if properly distributed and if your TV has payload capacity to handle the extra weight without being overloaded over the GVWR of the TV. 10% to 12% is acceptable but will more likely result in trailer sway under extreme conditions, even with a good sway control hitch. NEVER
allow less than 10% under any conditions, and work hard to get it over 11%.
Compute percentage of hitch weight distributed off the rear axle of the TV when the spring bars are attached.
TV rear axle weight without spring bars minus TV rear axle weight with spring bars, divided by hitch weight.
Goal is 50% of hitch weight left on the rear axle (or distributed off the rear axle). Reasonable range is 40% to 60%.
You can adjust that percentage by loosening or tightening the spring bars. One chain length can make a big difference.
Compute percentage of hitch weight distributed to the trailer axles.
Trailer axle weight with spring bars
minus trailer axle weight without spring bars,
divided by hitch weight.
Goal is 25% (reasonable range about 20% to 30%).
Compute percentage of hitch weight distributed to front axle.
Weight on front axle with spring bars
minus weight on front axle without spring bars,
divided by hitch weight.
Goal is 25% (range 20% to 30%)
After you have the spring bars adjusted to distribute about 50% of hitch weight off the rear axle, if the weight distributed to the front and trailer axles is not reasonably close to 25% each, adjust the angle of the hitch ball to the coupler.
If you have to do much adjusting, then you need another set of scale weights to check your percentages again. (Yes, make friends with a CAT scale operator!)
Since you have all the numbers available, check for overloading.
Trailer axle weight should be less than the combined GAWR of the TT axles.
The weight on the 4 TV tires (GVW) with trailer tied on and spring bars installed should be less than the GVWR of the TV.
Gross weight of TV and TT should be less than GCWR of the TV.