Figure the impact of a battery bank on tongue?

[Fishalaska1]

Originally Posted by SmokeyWren

The only way you're going to know for sure is to weigh the rig three times on the CAT scale,

1] Truck only, no trailer.

2] Truck and trailer, no weight in the trailer's garage, and with the WD hitch adjusted to where you think it should be for that trailer with no weight in the garage.

3] Truck and trailer with loaded garage, and with the WD hitch adjusted to where you think it should be for that trailer with the loaded garage.

Compute the GVW on the two truck axles for each condition 1], 2], and 3] above.

2] minus 1] is the tongue weight of the trailer with no cargo in the garage.

3] minus 1] is the tongue weight (TW) of the trailer with a loaded garage.

Compare 3] to the GVWR of the tow vehicle to determine if you exceed the payload capacity of the tow vehicle.

4] Then for complete info to check the adjustment of your WD hitch, weigh the rig one more time, same as 3] but with the spring bars of the WD hitch disconnected.

Then compare the difference of weight on each axle group on the rig, with and without the spring bars adjusted, and compute the percentage difference the spring bars make. Your goal is 20 to 25% of TW distributed off the rear axle and onto the trailer axles. And another 20 to 25% of TW distributed off the rear axle and onto the front axle of the tow vehicle. That leaves 50 to 60% of TW remaining on the rear axle of the tow vehicle.

If you have more than 60% of TW remaining on the rear axle, then you need to tighten the spring bars a bit more. If you have less than 50% of TW remaining on the rear axle, then you need to back off of the tension on the spring bars a bit.

If you don't have about the same percentage distributed to the front and trailer axles, then you need to adjust the angle of the ball mount to the coupler. IOW, if you have 1,000 pounds TW, you want about 400 to 500 pounds distributed off the rear axle. 220 to the front and 220 to the trailer axles would be 440 total distributed off the rear axle, or almost perfect. But 120 front and 320 to the trailer would still be 440 distributed off the rear axle, but should need more playing with the hitch adjustment.

Then weigh the whole shebang again to be sure your adjustments worked.

I don't mess with adjusting the ball mount until after I get the correct weight distribution removed from the rear axle. Then after you have 50 to 60% of the total TW remaining on the rear axle, don't change the tension on the spring bars again, and instead worry about the angle of the ball mount to the coupler.

Yes, unless you are really good at estimating weights, you'll get to know the scale attendant really well before you get the WD hitch properly adjusted.

Yep. Whats a CAT scale visit now $20.00?

[ModestMonk]

Originally Posted by Fishalaska1

Yep. Whats a CAT scale visit now $20.00?

Nearest one to me is 2 1/2 hours away.

[Highway 4x4]

The shock load of a big bump could multiply the added weight by a factor of 5, just my guess. But the tongue and frame is designed to take more than the weigh ratings for that reason.

[drittal]

Our landfill let's us weigh for free.

[ModestMonk]

Originally Posted by Highway 4x4

The shock load of a big bump could multiply the added weight by a factor of 5, just my guess. But the tongue and frame is designed to take more than the weigh ratings for that reason.

If it wasn't secured, I bet you're right.
I would think ORV's frames would be worthy of that consideration.

[ModestMonk]

Originally Posted by drittal

Our landfill let's us weigh for free.

There's usually a waiting line there. Maybe I could come early or late some day.

[SmokeyWren]

Originally Posted by Fishalaska1

Yep. Whats a CAT scale visit now $20.00?

Cat scale prices vary. The last one I had done was at the Pilot Travel Center near Midland, and it was $10.50 for the first weight. Back in 2012 when setting up my WD hitch for my new TT, in Pecos at Flying J, I paid $9.50 for the first weighing, then $1.00 for a reweigh.

Why did I need a reweigh? Adjusting up the the WD setup during a towing trip to El Paso. So I weighed once with the spring bars tight, then reweighed without the spring bars.

Tongue weight per my TW scale: 650

Without spring bars:
Steer 3040
Drive 3880
Trailer 3480
Gross 10,400

With spring bars:
Steer 3280 so 240 added to front axle = 37% pf TW = too much

Drive 3520 so 360 TW distributed off the rear axle, leaving 290 on the rear axle = 44% of TW = not enough TW left on the rear axle.

Trailer 3620 so 140 added to trailer axles = 22% of TW = just right
Gross 10,420

So I needed to reduce the tension on the spring bars a bit to increase the weight on the rear axle, and adjust the angle of the ball to the coupler to distribute less weight to the front axle of the tow vehicle without screwing up the weight distribution back to the trailer axles.

There's a 20# scale error caused by rounding the weights on the three scale pads.

[Fishalaska1]

Originally Posted by SmokeyWren

Cat scale prices vary. The last one I had done was at the Pilot Travel Center near Midland, and it was $10.50 for the first weight. Back in 2012 when setting up my WD hitch for my new TT, in Pecos at Flying J, I paid $9.50 for the first weighing, then $1.00 for a reweigh.

Why did I need a reweigh? Setting up the the WD setup during a towing trip to El Paso. So I weighed once with the spring bars tight, then reweighed without the spring bars.

Tongue weight per my TW scale: 650

Without spring bars:
Steer 3040
Drive 3880
Trailer 3480
Gross 10,400

With spring bars:
Steer 3280 so 240 added to front axle = 37% pf TW = too much

Drive 3520 so 360 TW distributed off the rear axle, leaving 290 on the rear axle = 44% of TW = not enough.

Trailer 3620 so 140 added to trailer axles = 22% of TW = just right
Gross 10,420

So I needed to reduce the tension on the spring bars a bit to increase the weight on the rear axle, and adjust the angle of the ball to the coupler to distribute less weight to the front axle of the tow vehicle without screwing up the weight distribution back to the trailer axles.

There's a 20# scale error caused by rounding the weights on the three scale pads.

Ahhhh. Mine is a 5er so I guess I weigh truck empty and get front and rear axle weights? Then hook up and get front and rear axle weights on the truck and subract rear to get pin weight? Add them all to get combined weight? Add pin weight to trailer axle weights to get trailer weight?

[SmokeyWren]

Originally Posted by Fishalaska1

Ahhhh. Mine is a 5er so I guess I weigh truck empty and get front and rear axle weights? Then hook up and get front and rear axle weights on the truck and subract rear to get pin weight?

Not exactly.

Combine the weights on the front and rear axles to get GTW, with and without the trailer tied on. Subtract GTW without the trailer from GTW with the trailer to get pin weight.

If your 5er hitch is properly installed with the center of the kingpin about 3" to 4" in front of the center of the rear axle, then some of the pin weight will be on the front axle. The two CAT scale report will prove this.

Add them all to get combined weight?

No need to add anything. The CAT scale report with trailer tied on will give you gross combined weight.

Add pin weight to trailer axle weights to get trailer weight?

Right. But trailer weight is a useless number other than for estimating hitch weight when matching trailer to tow vehicle. When on the road, compare combined gross axle weight rating (GAWR) of the trailer to the trailer axle weight per the CAT scale report. Compare GVW of the tow vehicle with the trailer tied on to GVWR of the tow vehicle.

[Fishalaska1]

Originally Posted by SmokeyWren

Not exactly.

Combine the weights on the front and rear axles to get GTW, with and without the trailer tied on. Subtract GTW without the trailer from GTW with the trailer to get pin weight.

If your 5er hitch is properly installed with the center of the kingpin about 3" to 4" in front of the center of the rear axle, then some of the pin weight will be on the front axle. The two CAT scale report will prove this.




No need to add anything. The CAT scale report with trailer tied on will give you gross combined weight.



Right. But trailer weight is a useless number other than for estimating hitch weight when matching trailer to tow vehicle. When on the road, compare combined gross axle weight rating (GAWR) of the trailer to the trailer axle weight per the CAT scale report. Compare GVW of the tow vehicle with the trailer tied on to GVWR of the tow vehicle.

So I can get all this on a Cat scale with 2 weighs. One just truck and one with everything hooked up? The scale weighs each axle separately?

[SmokeyWren]

Originally Posted by Fishalaska1

So I can get all this on a Cat scale with 2 weighs. One just truck and one with everything hooked up? The scale weighs each axle separately?

The CAT scale has three pads. One for the front axle, one for the rear axle, and one for the trailer axles. The scale report will give those three weights, as well as the gross weight of the rig.

CAT is an acronym for "certified automated truck". The automated part means it's run by a computer, so it's simple for the computer to add the three weights and print out the gross weight.

The CAT scale is normally used by 18-wheelers, but it works fine for a pickup or SUV dragging an RV, cargo, or other type of trailer.

[Fishalaska1]

Originally Posted by SmokeyWren

The CAT scale has three pads. One for the front axle, one for the rear axle, and one for the trailer axles. The scale report will give those three weights, as well as the gross weight of the rig.

CAT is an acronym for "certified automated truck". The automated part means it's run by a computer, so it's simple for the computer to add the three weights and print out the gross weight.

The CAT scale is normally used by 18-wheelers, but it works fine for a pickup or SUV dragging an RV, cargo, or other type of trailer.

Cool, so just two weighs....truck full and ready and then whole rig completely full and ready?

[SmokeyWren]

Right,

[Fishalaska1]

Originally Posted by SmokeyWren

Right,

How do the pads work so they are spaced correctly for vehicles of different lengths? The pads move?