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Old 11-18-2018, 09:10 PM   #51
gearhead
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With the Pullrite Superlite you have the choice of how you mount the ball on the trailer. A bit forward for more truck to 5th cap clearance, or swing it around 180 degrees for less clearance. It's not much difference, maybe 3-4 inches.
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Old 11-21-2018, 10:34 AM   #52
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Originally Posted by 7Iron View Post
Yesterday I just purchased a 2018 6.7PS F350 SRW LB(176") CB...getting prep'd for a 5er, we currently have a TT

What I am struggling with is the impact on Rear Axle wt when you add a 6" aft lever (offsetting the pin 6 inches to the rear) . I am certain there is some physics at play, I just haven't noodled what.

To mentally test if impacted, I imagined a 60ft rear lever....(offset the pin 60ft), there would be a substantial reduction to frnt axle load and a significant increase to the rear axle load....what does 6" do? (what is the math...is it closer to 6lb, 60lb or 600lb impact)
One of the engineer guys will have to respond on this, but I'm pretty sure you dont have a 60 ft fulcrum. It will be at the axles, so closer to 40ish foot. If you move the connection point back, maybe that causes a second fulcrum? The Anderson guys should be able to answer this. I'd call them.
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Old 11-21-2018, 05:37 PM   #53
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The fulcrum is actually the truck rear axle. The formula to calculate the resulting force at the front axle is F1*D1 = F2*D2, where F1 = FA unloading, D1 = truck wheelbase, F2 = trailer pin weight (downward force), and D2 = hitch to RA distance. Solving for F1 = (F2*D2)/D1. Guessing a 5er weight of 15K# with a 3K# pin weight. Using your truck wheelbase (176”) and hitch 6” aft of RA, the resulting unloading of the front axle would be around 102#.
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Old 11-22-2018, 06:03 AM   #54
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Originally Posted by dbear View Post
The fulcrum is actually the truck rear axle. The formula to calculate the resulting force at the front axle is F1*D1 = F2*D2, where F1 = FA unloading, D1 = truck wheelbase, F2 = trailer pin weight (downward force), and D2 = hitch to RA distance. Solving for F1 = (F2*D2)/D1. Guessing a 5er weight of 15K# with a 3K# pin weight. Using your truck wheelbase (176) and hitch 6 aft of RA, the resulting unloading of the front axle would be around 102#.
And there you go. Thanks.
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Old 11-22-2018, 07:16 AM   #55
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I'll string line the bed pin later on to the center axle , the hitch looks near center . I know the goose box adapter extends 5 inches center to center forward . That extends the turning radius. Where is the weight being distributed with extended goose box?
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Old 11-28-2018, 07:17 PM   #56
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Originally Posted by gearhead View Post
With the Pullrite Superlite you have the choice of how you mount the ball on the trailer. A bit forward for more truck to 5th cap clearance, or swing it around 180 degrees for less clearance. It's not much difference, maybe 3-4 inches.
I tried the Pullrite and with the offset ball thingy it ended up messing with my Trailair rubber isolating pad on the pinbox. Crushed it at the front to the point that I was uncomfortable towing with it. Pullrite offered up a steel tubing spacer solution but all it did was nullify the rubber isolation pad. Stick with a good 5th wheel hitch and get some sort of truck crane attachment for your rear hitch to remove the 5th wheel hitch.
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