King Pin Weight

[sonofagun]

Followed a thread on EXPSD's new 5th wheel and I would like to pursue my questions about allowable king pin weight in the 2500HD. I'm looking at a 5th wheel (Mobil Scout) that has a gross weight of 13000# (no problem there). It has three slides and a king pin weight of 2318#.EXPSD figures his is around 2500#. That, on first look, seems ok too. BUT.... The truck has a gross vehicle weight of 9200# and a rear axle capacity of around 6000#. The owners info says the truck has a payload of 3300#.

SO>>>>>>>>>> If I do the following math:
3300# payload
- 2318# king pin
- 400# front of bed 42 gal. fuel tank
- 300# Me and the wife
- 200# 5th wheel hitch
- 100# manik grill guard, side rails and wind deflector.
That totals 3318# with nothing in the truck but us and nothing at all in the 5th wheel in the way of food, clothes, dishes, FISHING GEAR, etc.

How are you guys pulling your 5th wheels around without grossly over weighing your gross vehicle ratings? I know the factory fiqures are conservative but who wants to argue with the dealer if the Allison goes, or the insurance co. if we have an injury accident that one of us is responsible for? I can only cram so much stuff in the back to counter weight the king pin. What are your thoughts?

[4x4man]

Son of a Gun-

I would weigh your truck first full of fuel with your wife and you in it. This will give you actual weight information, then you can determine how much king pin wieght you can legally carry. I weighed my truck full of fuel with the wife and I in the truck, no 5er hitch (hadn't been installed yet) and the truck weighed 6572lbs. Subtract that from 9200 GVWR and it left me with 2628lbs of payload (where is my large payload now??). Maybe if I had a Reg cab with nothing in it (options) I could acheive 3,300lbs of payload. Estimate the hitch around 100-150lbs depending on what you get and you are left with around 2,500 lbs for king pin weight. Our 5er has a king pin weight of around 1,700 lbs. We have not wieghed the total rig yet, but estimate it to be around 10,000lbs loaded. GVWR of the trailer is 11,760 lbs.
I would weigh your truck first before looking at trailers if you are concerned about staying legal. The sales people will tell you anything to get your money. Be prepaired!!

Hope this helps.
Bob

[Diesel Dad]

I second the "weigh the truck" comment. We had a 2001 2500HD LT CC SB D/A with minimal aftermarket equipment. With 350 lbs. of passengers, fifth wheel hitch, roll-n-lock and running boards, the truck weighed 7400 lbs. leaving only 1800 lbs. for pin weight.

With the extra fuel tank, you may have less available payload. There are two other sources on info on what your truck really weighs. On the new vehicle information statement (NVIS) that you give to the motor vehicle licenser to register the vehicle for the first time, there is the actual weight of your truck leaving the factory. If you add the items you identified to the NVIS weight, it will be close.

The other source of payload info is the camper sticker in the glove box of your truck. It will list capacity of the truck including passengers in each seat at a weight of 150 each.

I bet you would be 500 to 1000 lbs. over GVWR as outlined.

Regards

[Maverick]

The truck can handle alot of pin weight. This is how my truck weighs out regularly with 3 vehicles on the 51' trailer.

Steer------4,380
Drive------9,480
Trailer---17,720
GVW-------31,580

A wimpy 16K is no problem. And yes I know my truck is a dually.

[David Utz]

Have a look at: http://forum.62-65-dieselpage.com/cg...=7&t=003908&p=

[ 10-03-2002: Message edited by: David Utz ]</p>

[Speedy]

The real issue you need to think about is the GCWR & braking, not whether the weight will handle it or not on the axle. If you ever had to do an emergency stop you had better have the trailer brakes cranked pretty tight. I have a similar setup to Maverick that I pull w/ 3500 once in awhile (my normal tow rig is a topkick/cat GCWR=65,000). I can tell you from experience if some little rice rocket pulls out in front of you w/ a 2500 loaded above 20K and you have to lay on the brakes it will be a very scary situation.

I am as bad as anyone to ignore what is prudent; but consider this. If you ever got in an accident and knowingly exceeded the GCWR you are at risk to one helluva lawsuite! And worse yet if someone was killed, you would feel even worse. It is better to be on the safe side, than push the limits!

So if you are going to tow a large trailer, get a 3500 or larger rig to tow it!

[sonofagun]

Here is the latest to this unending saga(with no answer):

Everything is weighed. The 5th wheel weighs 11,200# loaded. Truck weighs 7420# with me, 69 gal. of fuel and the 5th wheel hitch. Wife would add 125#. So far I'm not over the allowed combined. I will be over the 1780# left between the 9200# and the 7420# weight.

Trailer has hydraulic over elec. discs. Front of truck weighed 4180# versus 4670# axle cap. rear weighed 3240# versus 6080# axle cap. Since the axles will carry 10750# and GM says I can pull a 15800# 5th wheel you would expect an acceptable king pin to be to be 3160# (20%) to 3950# (25%). The GM literature says up to 3000# is the max. so obviously no one can haul a 15800# 5th wheel with this truck(assuming nothing else was in the truck by the way). So which is it?

If I go with axle capacity as the more reasonable number (versus the unrealistic 9200#) I can carry an additional 2840# in the bed. The king pin on this 5th wheel is 2300#.(Remember I can only have 1700# versus the 9200# GVW.)

I have Michelin 265/75s with a load capacity of 3400# each so no problem there either. I have 2500# airbags on the truck (versus JKs idea of an additional leaf). The trailer is only 31 feet long so there should be no stability problems that you might expect with a longer unit and a single rear axle.

Here's my ending decision:

10750# axle capacity
13600# tire capacity (6800#) on each axle

10750# allowable gross truck weight
truck weight -7500 actual, loaded.
leaves me 3250# in the bed. Can't go there so
going with the rear axle capacity of
6080#
-3340# actual rear truck weight means I still have 2840# for king pin and truck junk.
Long post but where are the holes?
Thanks for all the good input so far.

Bob

[Colorado Kid]

You're within all axle weight limits, tire weight limits and the Gross Combination Weight Rating. I think you're golden.

I've said before that I don't believe the GVWR means anything once you hitch up. If the truck is hitched to a trailer it's a combination. The axle and tire ratings (of course) still apply.

Happy trails!

[Diesel Dad]

Here is some more food for thought.

I had exactly the same problem with our fifth-wheel (Cardinal 31-2BHLE) and a Chevy Silverado 2500HD LT D/A CC SB. Our stats were:
Truck + passengers (2500HD) - 7400 lbs
Pin Weight - 2332 lbs
Total Trailer Weight - 10,912 lbs
Truck + Pin = 9732 GVWR

There is no way to take 500 lbs. out of the truck weight or pin weight. I considered removing the factory receiver hitch (60 lbs), removing the roll-n-lock (100 lbs) etc. And the pin weight of our trailer empty was 2100 lbs., so 2100 + 7400 = 9500 lbs -- we were 300 lbs. over the limit empty.

I'm sure that the truck would tow the load and stop it without too much drama, as long as you never have a blowout on a rear truck tire. The axle and brakes on a 2500HD are the same as a 3500.

That being said, we sold our 2500HD and bought an identical used 3500 at a loss of about $3K. We looked also at an F-550, but it was overkill for our needs.

The 3500 weighs 8162 with passengers etc.

Our reasons were:
1). Increase safety of having dual rear wheels. And yes, it really does tow better than the 2500HD.

2). Potential liability -- did not want to risk losing everything in an accident if being over the GVWR was deemed to be a contributing factor. There are 50 states and 10 provinces, hundreds of courts, could never be sure it wouldn't happen.

3). The risk of being stopped and fined or sent home for being over GVWR. Our neighbouring province, BC has done exactly this from time to time. Here is a link to the Insurance Corporation of British Columbia web site (they set enforcement policies for the province of BC):
http://www.icbc.com/FAQs/GVWR.pdf#Page2

South Dakota did this for a while. Others may start. The trend is toward increased enforcement, not less. GVWR violations are easy to catch -- GCWR violations are nearly impossible.

So, after biting the bullet, I'm happy to have the 3500. The improvements are:
1). The long box is easier, since I was able to get rid of my sliding hitch. I will also soon get rid of my extended pin box.
2). Room for the future. I have 900 lbs. to spare in GVWR for toolboxes, fuel tanks, bikes etc.
3). Better ride. The 2500HD is harsh when empty. The 3500 is much better except for big potholes.

In the long run, you may be happier with the trailer of your choice and a 3500. Just my opinion.

Our RV dealer also let us take a trailer like the one we were ordering over the weigh scales to get an actual dry weight and pin weight. Never the same as the brochure.

[ 10-04-2002: Message edited by: Diesel Dad ]</p>

[Vette Racer]

I know you will never look back if you go with the 3500. Everyone I know that tows with a 2500, even if they are not loaded heavy, talks about sway when towing. I can tell you that with the 3500, pulling a 38ft 5th wheel with 3200lb pin weight, this thing is great, no sway, even in heavy side winds, its right on down the road, period!!! If you have any question as to what to do,then you should go with the bigger truck.

[needbigtruck]

Based on what Diesel Dad said, I pulled out my registration. It says Wt/seats 8000 (registered in NYS). I never really looked at that before. The dealer registered it for me. So does that mean all I can legally carry is 1200lbs. I agree with Colorado Kid that GVWR doesn't mean anything when you are hooked to a trailer. What about Dodge with it's new SRW 3500. What is the GVWR of that truck. The brochure doesn't really say. Ford does the same thing with the SRW F350. If the brakes and axles on our trucks are the same from 2500 to 3500 then the load rating should be a combination of what each axle can carry, not some arbitrary number that GM can change just to go ahead of, or keep up with the competition.

[Diesel Dad]

GM has not changed the GVWR rating since the truck was introduced. GM now has the lowest GVWR ratings of the three manufacturers.

In the one-ton DRW, Dodge is now the leader at 12,000 GVWR and Ford has 11,500 GVWR. In SRW, GM is at 9200 and the other two are at 9,900.

The 700 pound gap in the one-ton SRW really looms large when towing a 5er since it translates into the weight of a bedroom slide.

Cheers.

[EXPSD]

Here is the numbers for my MobleSuite 36 foot fifth:
Manufacture dry weight per label inside 5th 12,219#
Actual weight, loaded ready for vacation, driver/wife in cab, but with little water, black, grey, or fresh. Duramax with about 25 gallons of fuel.
Steer axle 4280#
Drive 6260#
Trailer axle 11240#
Gross weight 21780#

Truck pulls, stops great and handles very well. It does sit down about 4 inchs when loaded, which if corrected may even take some of the weight off the rear axle. I do have Mich. 265s which are rated at 6800# per axle. Comments?

[sonofagun]

EXPSD,

You have the same issue I do, only a bit more so. Do you have airbags on your truck? I am most concerned about exceeding axle and tire load ratings. The rear axle is rated 6080#. I'm not over that but you are by a bit. I was suprised to note that my factory tires (E load rated) had a capacity of only 2778#. Ticks me off that GM would put tires on this truck that don't carry the axle load!. But that took me to the Michelin 265s with their 3400# rating. You might be able to move a couple of hundred pounds to the rear of your 5th wheel when you travel or pull the factory hitch if you don't plan to use it. I put a camping world clamshell carrier on the top of my trailer (rear) that will hold 150 pounds. That might help shift some wieght. It was pricey at $270 and add 43# by itself. I have 43 gallons of fuel in the back of my truck bed so that squeezes my load even tighter. I can always carry a bit less fuel.
A long bed dually won't fit in my garage and a new house is not an option!

I am gona go with what I have and see how see pulls to Utah this summer. My 5th wheel is only 31 ft long so I'm not going to have any stability problems in my opinion. I think I'm ok as long as I stay under the gross ratings. The airbags will bring the trailer level and they are a good investment.

Colorado, I'm with you. Thanks to all for their input into this very confusing (thanks to GM, F*** and D****) issue.

Regards,

Bob

[EXPSD]

I do not have air bags, but a local very reputable and knowlegable auto/truck spring manufacturer and installer recomends the Timbren Aeon Rubber springs. I am going to post on after market and see if others have experience with them.

[Viking]

EXPSD, I have the Timbrens on my vehicle. Very easy D.I.Y. They work well for my 1800# kingpin weight.

[sonofagun]

EXPSD, Viking,

Do the Timbrens allow you to adjust anything to compensate for weight differences like airbags do?
When empty I run my airbags at 5#-10# and they take some of the empty jolt out of the rear end. When loaded I run them up to level the truck. I have guages inside and a remote compressor so it all works from the drivers seat.

Good luck and good trailering EXPSD.

Bob

[Viking]

Timbrens are not adjustable.

When installed in place of the rubber bump stops above the rear axle there is approx a 1" space between the timbren and the bump stop plate on top of the axle. As load is placed in the bed, the timbren makes contact with the bump stop plate on top of the axle and it will then compress as the load is increased or a bump is encountered.

I suspect that airbags would give a smoother ride overall.