RCMAN46 wrote:
Cajun Bill wrote:
Okay sports fan, OP here. Got 'er done this morning.
Truck only:
steer axle 4400
drive axle 2920
total weight 7320
truck and fiver:
steer axle 4220
drive axle 5460
trailer axle 9720
total weight 19400
Note: people weight--driver 275 lbs. (no derog comments please)
gray and black tanks empty, fresh water--approx 15 gallons
fuel tanks 1/2 full (13 gal. diesel)
Other info---according to my truck manual, GCWR is 22,000 lb, so my 19400 is well within limits. Max trailer weight according to manual is 14,200 lbs and at 12,080, that gives me over 2k more carrying capacity and since the trailer has almost everything I normally carry except groceries and clothes. The most passenger weight I might have is an additional 460 lbs.
Now, what is my pin weight? 5460-2920= 2,540 lbs.???? And if that is close, am I within limits?
Your true pin weight is 2360.
You have a truck on the scales that weighs 7320 (4400+2920)
Now imagine the truck is still on the scales and you lower the trailer pin on to the truck. Now the truck weighs 9680 (4220+5460) You had to add 2360 to get the truck to weigh the 9680.
Believe what you want but your actual pin weight is 2360.
Your pin percentage is pin/trailer. 2360/12080=.195 or 19.5%. A little low for a 5th wheel to handle well and not chuck.
Your hitch must be a couple inches behind the centerline of the rear axle or there was no driver in the truck during the second weighing.
This is why it is important to know actual pin weight.
Another way to look at this. Truck and trailer weighs 19400 and the truck weighs 7320. That means the trailer weighs 12080.
The trailer axle weight was 9720. Pin =total trailer-trailer axle.
12080-9720=2360.
But to be accurate there can be no loading changes between weighing's. The same people, fuel or anything else has to be in the truck both times.
How do you come up with 2360???? Rear axle weight, empty was 2920#, With the 5th wheel hitched to this truck, his rear axle weight went to 5460....5460-2920 still equals 2540 pin weight...What type of math get's you 2360? 180# LESS than what is showing. Just curious as to if some type of new math is being used to determine pin weight now. Heck, I had a DOT weight officer at the scales with me while I was weighing to make sure I pulled on the scales correctly and he was doing the math for me, though I didn't need it, and My pin weight was truck drive axle weighed without 5er, then with 5er loaded onto the hitch...difference was pin weight weight....it's not new fuzzy math...still the same math as always...
My truck had steer axle of 5460, drive axle of 7200#...meaning my truck weighed, (with pin weight), 12,660#...which is 1,340# under my trucks GVWR of 14,000#....The trailer axle weighed 12,580#....total weight of truck and 5er were 25,240#...subtract 12,580# from that and it leaves you 12,660# of 5er, plus the 3340# of pin weight, gives my 5er a weight of 15,920#..numbers didn't change....still had 3340# of pin weight....no fairy dust, just basic math and a tad of common sense.
Also having owned several 5er's with GVW's of 12,000# and 14,500# and pin weights lighter than what you alluded to of 19.%, will NOT necessarily equate to "chucking" or the 5er "not handling well"....that's too much of a blanket statement to hold true.....
