Trying this out on my truck and 5th Wheel. There are a couple of terms I need a little explanation on. For both units they are asking for Steer axle and Drive axle. What are those? Are they found when I go to a scale? For the 5th Wheel they ask for Trailer axle weight. Would that be another term for my "advertised" dry weight? Thanks for any help on there terms.

Try this - truck - front axle = "steer" and rear axle = "drive". Trailer axle weight is as it is. But your trailer wheels/axles should be equal from left and right and the front pair and rear pair should also be equal.Perfectly clear??

Truck has a 'Steer Axle' (That's the Front axle) and a 'Drive Axle' (That would be the Rear Axle)5th wheel only has Trailer Axle. Forget that 'advertised dry weight'.When you go to scales you will want to get two complete weigh ins.1st weigh in...Drive truck with trailer hooked up onto scales (3 separate platforms)Truck front axle on front oneTruck rear axle on center oneTrailer axles on rear oneTell scale operator you are 'private'...they will weigh combo and then you pull off scales.Go to back of parking lot and drop 5th wheel.Go back onto scales with truck front axle on forward platform and rear axle on center on.Tell scale operator.........'private-reweigh'.They will weigh. Pull off scales.....go park and go inside to get weigh tickets.One will have the truck Front/Rear Axle weight and the trailer axle weightThe other one will have truck F/R axle weights.You then have ALL the weight numbers to figure out:Weight on truck F/R axles hooked up to 5vrThe 5vrs axle weight when hooked up to truckThe truck/trailer combo total weightWeight on truck F/R axles when NOT hooked to 5vr...plus trucks total weightThe difference in trucks rear axle weight when hooked up to 5vr and when NOT hooked to 5rv is the 5rvs 'Pin Weight'The 5rvs pin weight plus trailers axle weight will be the 5vrs total weight.You can then compare the various weight numbers to your trucks axle ratings, tire load ratings, GVWR, trailers GVWR and the trucks GCWRFAWR.....front axle weight ratingRAWR.....rear axle weight ratingGVWR.....gross vehicle weight ratingGCWR.....gross combined weight ratingRatings will be on door jam sticker, on trailers VIN Data Plate and on sidewall of tires.EDIT: Spelling...lack of some letters in words----keyboards fault :S

ramyankee wrote:Trying this out on my truck and 5th Wheel. There are a couple of terms I need a little explanation on. For both units they are asking for Steer(front) axle and Drive (rear)axle. What are those? Are they found when I go to a scale? For the 5th Wheel they ask for Trailer axle weight. As it says, trailers axle weight. Weight of the loaded trailer minus pin weightWould that be another term for my "advertised" dry weight? A figmant of someones imagination. This number is calculated based on engineering calculations. Not really worth a hoot except for something to put in the brochure in an attempt to sell unsuspecting people more trailer than their tow vehicle can handle.Thanks for any help on there terms.Based on the little information you have provided, I assume you have a 2500HD? That being said, you need to load it up like your going camping and drive to the scales. To that number add 250 pounds for a hitch, 350 pounds if you need a slider hitch. Now, look on the drivers door post for the factory published GVWR 9200 for a 2500HD and 9900 for a 3500 SRW. Subtract your scaled weight from that number. That is how much weight you can add to the truck before you exceed the manufacturers numbers.Back when I foolishly bought a Chevy 2500HD D/A it scaled ready to travel at 7500 pounds. Meaning I had about 1700 pounds of payload. I suspect your numbers will be similar.To make a best guess estimate for what fifth wheel you can tow, use 20% of the fivers GVWR as pin weight. In reality a 10,000 GVWR fifth wheel will have a pin weight around 2000 pounds. Does this make sense now?

MOST EXCELLENT post, OB.....pretty much covered it all:B

More Info......IF you don't have the 5th wheel and are trying to calculate what you can tow etc.Get the truck weights (F/R axle)The difference between trucks rear axle as weighed and the trucks RAWR will be the 'payload' available-------that will be trailers pin weight.Keeping in mind the trucks rear tire MAX Load Rating at MAX PSI (on sidewall).And the trucks GVWRThen you have a starting point....Look at the 5th wheels GVWR (on Data Plate) and using 20% of that number will give you a 'guesstimation' of what the 5vrs 'wet' pin weight would be.Typically you want at least 20% pin weight for good towing..lighter pin weights can result in 'chucking' (Actual pin weights can be higher than 20% but it's a good 'guesstimate' number without actually weighing)Example:Truck weighs 7000# camp ready (you, passengers, any stuff in cab, hitch(200#), and fuel) Front axle----3800# Rear axle---3200#Trucks RAWR is 6200#........so that leaves 3000# payloadTires are rated at 3200#/each (6400# total)Truck GVWR is 10,100#Trailer GVWR is 12,000#20% is 2400#So truck has enough payload (3000#) for the 2400# pin wetTrucks rear axle (Rated @ 6200#----weight is 3200+2400=5600) has enough capacity for the 2400# pin weight Rear tires have enough load capacity at max psi (Rated @ 6400#----weight is 5600#) for the 2400# pin weightTruck has enough GVWR (Rated @ 10,100#.....weight is 7000+2400=9400) for the 2400# pin weight>>>>>>>>>>>>DISCLAIMER><<<<<<<<<<<<The above is just an example of the math..numbers are made up to fit scenarioReal World numbers WILL be completely different

Term question re: weight calc/load estimate utility

Old-Biscuit
Explorer III
Jan 30, 2014
Truck has a 'Steer Axle' (That's the Front axle) and a 'Drive Axle' (That would be the Rear Axle)

5th wheel only has Trailer Axle. Forget that 'advertised dry weight'.

When you go to scales you will want to get two complete weigh ins.

1st weigh in...

Drive truck with trailer hooked up onto scales (3 separate platforms)
Truck front axle on front one
Truck rear axle on center one
Trailer axles on rear one

Tell scale operator you are 'private'...they will weigh combo and then you pull off scales.
Go to back of parking lot and drop 5th wheel.
Go back onto scales with truck front axle on forward platform and rear axle on center on.
Tell scale operator.........'private-reweigh'.
They will weigh. Pull off scales.....go park and go inside to get weigh tickets.

One will have the truck Front/Rear Axle weight and the trailer axle weight
The other one will have truck F/R axle weights.

You then have ALL the weight numbers to figure out:
Weight on truck F/R axles hooked up to 5vr
The 5vrs axle weight when hooked up to truck
The truck/trailer combo total weight
Weight on truck F/R axles when NOT hooked to 5vr...plus trucks total weight

The difference in trucks rear axle weight when hooked up to 5vr and when NOT hooked to 5rv is the 5rvs 'Pin Weight'

The 5rvs pin weight plus trailers axle weight will be the 5vrs total weight.

You can then compare the various weight numbers to your trucks axle ratings, tire load ratings, GVWR, trailers GVWR and the trucks GCWR

FAWR.....front axle weight rating
RAWR.....rear axle weight rating
GVWR.....gross vehicle weight rating
GCWR.....gross combined weight rating

Ratings will be on door jam sticker, on trailers VIN Data Plate and on sidewall of tires.

EDIT: Spelling...lack of some letters in words----keyboards fault :S
crabbin_cabin
Explorer II
Jan 30, 2014
Try this - truck - front axle = "steer" and rear axle = "drive". Trailer axle weight is as it is. But your trailer wheels/axles should be equal from left and right and the front pair and rear pair should also be equal.
Perfectly clear??

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