K3500 rear axle rating

[JetBoater]

Can anyone advise the REAR AXLE gross limit weight for my K3500 Dually with 4.10 and auto transmission?

My door decal is worn off, the glovebox decal with all cryptic info is undicipherable.

I am getting close to my GVW of 6000 KG.

I just ran across a local scale with nothing loaded yet except boat fuel... and axle weights were as follows:

Front Axle: 1530 KG (3373 lbs)

Rear Axle: 3480 KG (7672 lbs)

Boat Axles: 2240 KG (4938 lbs)


Tongue weight: 370 KG ( 816 lbs) Extended 4.5 feet from back bumper.


Truck and Camper with boat hitched totals: 5010 KG (11,045 lbs) no extra gear loaded.
GVW: 6000 KG (13,227 lbs)


Truck/Camper (alone)
Front Axle: 1690 KG (3,703 lbs)

Rear Axle: 3060 KG (6,746 lbs)







Thanks

[a5150nut]

Might try here http://www.ehow.com/list_7530369_199...uck-specs.html and download the manual. It should break down the specs.

Do you have a leveler hitch to distribute the load back to the front?

[greatwhite]

That momma is loaded!

Might be worth your while to invest in a set of helper springs or air bags to level that rear out.

I know when I was in BC the RCMP were pulling guys over because the rig "looked" overloaded.

I asked a friend who was RCMP and he told me low hanging tails/high nose and/or bulged tires were what they looked for when pulling over RV pilots to check weights.....

[JetBoater]

i have 1 ton packs with overloads.... airbags are 95 on one side, 100 lbs on the side showing.

I've booked an appointment at my local spring shop to install beefier overload springs, as I currently have 1 single which is horizontal at the moment.

I'll look up my manual and check weights as well.

[JetBoater]

No luck finding my K3500 manual... that toolbar was unhelpful.

Can anyone advise the K3500, extended cab, diesel, dually, auto trans, 4.10 ratio axle rating?

[jamesm]

If I follow your math, the boat/trailer combo scales at 2240 + 370 = ~2610 kg. Following the standard 10-12 % as tongue weight for a bumper hitch, you should be 261-313 kg tongue weight.

You are at 370, leaving a "surplus" tongue weight of 57-109 kg. This weight, applied behind the rear axle, actually removes combination weight from the front axle and transfers it to the rear axle. Note how the boat affected the front (steering) axle to the tune of 1690 - 1530 = 160 kg, even though your gross combined went up by 2610. Less steering traction for more weight can detour you onto the trail of tears.

The settings on my equalizer hitch get more aggressive (transferring forward) by adding washers or reducing chain links. Each pass across the scales shown here, over about a 45-minute period at exact same burb/trailer/loads, adds stiffness to the equalizer setup. Watch the weights move around. On my Suburban, the rear axle rating is exactly equal to the capacity of two 245-75-16 LR-E tires, 2 x 3042 lb = 6084 lb. The axle/springs here are stronger than the tires. I'm not sure how it works with your dually. Sample data from my rig, trailer empty weight 7920 lb, running across the scales to get my equalizer set correctly.

Front axle, Rear axle, Trailer axles, Gross, load/setup
3580 3740 0 7320 suburban only
2980 5680 6580 15240 No EQ, empty trailer (front axle loses 600, rear gains 1940)
3120 5460 6660 15240 6 washers, 6 links (front axle loses 460, rear gains 1720, trailer gains 80 of its own weight back)
3260 5260 6700 15220 6 washers, 5 links (front axle loses 320, rear gains 1520, trailer gains 120 of its own weight back)
3400 5100 6740 15240 7 washers, 5 links (front axle loses 180, rear gains 1360, trailer gains 160 of its own weight back)

I would suggest moving the boat back on the trailer, putting the boat spare tire on the front bumper of the tow truck, or as mentioned getting an equalizer (leveling) hitch. The EQ puts tongue weight on the front axle of the tow vehicle and the axle(s) of the towed rig. Most suggest trying to return the front axle to near the un-trailered axle weight. Note that airbags, overload springs, etc, do not MOVE any weight, they only give the APPEARANCE of "leveling." Note that leveling, in this context, is not the same as BALANCING. Level = who knows? Balance = safety.

[JetBoater]

Jamesm - you follow my math fine. The boat is already hanging off the back of the trailer, and trailer design does not allow me to shift it's axles forward.

The steering was fine... I really don't notice any difference between towing and not towing except the amount of foot on the pedal (heavy) up hills.

I agree with balancing the weight and have considered the EQ Hitch... it is a necessary next step if I can't balance weight with my unloaded gear, this was previously mentioned by a5150nut. I have avoided EQ Hitch as my extension already rides low to the ground, and the EQ bars will definitely drag driving onto the BC Ferry.



I have the camper off at the moment to deal with new overloads on Tuesday.

Still looking for axle weight limit.
Thanks all.

[DmaxMaverick]

I don't know the exact axle rating of your truck. You'll have to decipher (or post a pic of) your RPO sticker in the glove box. The rear axle rating will be listed.

At any rate, your rear axle weight is not the problem (I'm sure your RAWR is 8K or better), and it doesn't appear to be "sagging", looking at the wheel to fender clearance. Your tongue weight and hitch position is. That is where your sag is coming from. Your hitch ball position appears to be about twice the distance from the axle as is the bumper (about where a "normal" hitch ball would be located). This means, your tongue weight is equivalent to about 1600 pounds on the hitch. You aren't "sagging", you are teetering. There's your problem! This is too much for ANY V-5 hitch system, even with WD.

You'll either have to install a dedicated hitch system designed to accommodate the heavy/extended tongue condition, lighten the tongue weight, or move that hitch position forward.

Adding weight to the front to compensate will improve the appearance, but will cause sever "porpoising" (teetering on the rear axle).

Getting your hitch geometry and weight correct will get it off the ground, too. If you use only a WD hitch system, the gain in hitch clearance will more than compensate for the additional hardware under the tongue.

[JetBoater]

Hi DmaxMaveric - thanks for update on what my axle should limit at. I'll post the decal later...when I get onto my laptop.

Measuring the fender height off the ground confirms what you say.
With camper on and airbags at 100 lb., fender height is 36" (3 feet even).
With camper on airbags deflated, fender height is 35".
With camper off, fender height is 37"
With camper on and boat hitched, fender height is 35.5"

Severe teeter/totter or see/saw effect. I never had this issue with the lighter boats I towed... this one tipped the scale.

The truck does slightly appear back heavy without the boat, so I am going to go ahead with new overloads... the overload I have is a single spring. I'll have the suspension shop provide some input.

I also go ahead with truck weight distribution system and let you all know how it goes.

I was contemplating leaving the camper behind in lieu of a tent. Cheaper but not really great for a 9 day trip. I'd miss my fridge and dry accommodation should it decide to rain. An 11.'5 camper is nice, but not necessary to catch fish...lol.

Then i thought I'd have my first mate tow the boat with my Durango... which is my current plan 'B' to ensure we get there safely.

Thanks for all the input, it is appreciated. I'll post an update after the weight distribution is figured out. I just hope the girl can climb with all this weight over the island mountain passes. I know she will, just a little hotter and slower than I prefer.

[JetBoater]

Here are the decals from glove box:

[JetBoater]

here is the extension:













Braced/welded and chained for safety... it never had any issues with trailer tongue weights less than 400 lbs.

If I can't get a WD hitch to work satisfactorily, the extension becomes a simple camper step.

[DmaxMaverick]

Also......

A standard/common WD hitch system isn't going to work. You will still be over the tongue limit by nearly double with the system.

In my opinion, increasing rear spring capacity any further is an exercise in futility. With (current) overload springs, and airbags (at max pressure), you will gain nothing but a weak(er) link. Getting it to stand up more is not the problem. I don't suggest trying to fix a problem that doesn't exist. The problem is the distribution of weight, and nothing else. Typical airbag systems at full capacity can increase load capacity by 5,000 pounds and more. Also consider the stress on the frame. Adding (excessive) weight is one thing. Compensating for that weight increases that stress. I think you're asking for trouble.

That is LOOOOOONG. Long for a 400 pound tongue, let alone one at more than twice that. You could gain some advantage by shortening the extension as much as possible, which appears to be more than a foot. This could be VERY significant, reducing the extended moment by more than 25%. The stress load on that 2" tubing is probably over rated too, with 800+ pounds hanging on it. It's just too little hardware capacity than what you are demanding of it. Something's gonna break, and it might be the frame first. I don't see any safe, workable solution with your current configuration. Plan B sounds much more reasonable until you get the geometry right.

[JetBoater]

Hmm... OK, plan B is sounding better.

The boat may now get towed with my first mate's 1995 1/2 ton silverado as we can throw more gear in the back of his pickup rather than my Durango.

Fancy step I have... maybe I'll weld a barbeque mount on it to make it more useful...lol

Cheers.

[DmaxMaverick]

As it stands now, according to your first post weight figures, you are over the GVWR of the truck, with or without the boat. Your GVWR is 10,000 pounds (C7A). Your brake rating is also stated 10,000 (JB8). The individual axle rating is not stated, it only refers to the sticker that should be on the door. You can get a replacement from the dealer with your VIN. In any case, it won't be more than the combined rating of the OEM tires. The ratings should be stated on the sidewalls, use the "dual" value, which is always less than the single rating.

[JetBoater]

The Load E tires state 1260 KG Dual.. so is that per tire per side (x4) = 5040 KG (11,000 lbs) ?

My insurance papers state GVW of 6000 KG... so did a previous owner increase the GVW?

Anyway, if my brakes limit out at 10,000 lbs 4,535 KG.... it is a mute point. Time for a different truck...

I have no trouble stopping the truck, even down long mountain grades. I do have new brakes all around though..

[DmaxMaverick]

The Load E tires state 1260 KG Dual.. so is that per tire per side (x4) = 5040 KG (11,000 lbs) ?

My insurance papers state GVW of 6000 KG... so did a previous owner increase the GVW?

Anyway, if my brakes limit out at 10,000 lbs 4,535 KG.... it is a mute point. Time for a different truck...

I have no trouble stopping the truck, even down long mountain grades. I do have new brakes all around though..

If the previous owner did in fact, uncrease the GVWR, you would have registration/government paperwork declaring it, and would probably be required to have it declared on the outside of the truck (large characters: "GVW 6,000 Kg", or some such). Your insurance company isn't going to "certify" your trucks limits. The ins. co. probably has "inclusive classes", and your truck is probably in the range "up to" 6,000 Kg. Rusty (TDP member) could probably offer more detail on that. I'm not up on Canadian vehicle laws, but my bet would be, in any case, weight limits will be "of the lesser", when a weight conflict arises. And in almost every case in the U.S., a vehicle can not be rated higher than the OEM's original weight declaration. Some commercial use vehicles can be uprated, but it's a matter of money (taxes) and paperwork. I can't imagine Canada being any less restrictive in this case.

Good luck and stay safe, no matter how you get this figured out.

[DmaxMaverick]

Also, your insurance may cover up to 6,000 Kg, including cargo and trailer (GCWR). Better confirm that with your policy.

[JetBoater]

i made a visit to autoplan agent and they advised my vehicle type is classed as COMMERCIAL. I asked why, they couldn't advise me with any reason.
GVW(kg)Disp.(cc) 6000 KG
New weight (kg) 02793
I have always insured the truck for pleasure use only..
The Commercial limit (if driven for such things as work) is allowed up to 6 days per calendar month, and limit is 5001 KG GVW.

They couldn't advise me with GCWR... and provided a government number which is of course closed today.

I guess the payload over bare-bone truck weight of 2,793 KG is the thing to watch... so time to unload unnecessary items from camper. I won't be towing this tub behind it. The truck is always 3000 KG at the dump scale... so I have some weight left to play with..

Thanks for your input DmaxMaverick

[rustyk]

Rusty (TDP member) could probably offer more detail on that.

While "Personal Auto Policies" (PAP) are somewhat standardized in the U.S.by using ISO (Insurance Service Office) forms, states and insurors can tailor those forms to laws and underwriting guidelines. Trucks up to 1T (mfr's classification) can usually be insured on a PAP, without regard to GVW or GCVW. However, companies will require trucks used in business to be on a Business Auto Policy (BAP). Trucks rated over 1T have to be on a BAP, and GVW/GVCW is usually required. Exceptions to the weight requirement are motorhomes (All classes); some companies permit motorhomes (usually up to 26K GVW) on PAPs.

Bottom line: There is no universal answer, so check with your insurance agent, and confirm in writing.

[JetBoater]

Thanks Rusty, I wait for the BC government office to re-open Tuesday due to the BC Day holiday today. I'll see what they have to say.

The pressure is off at this point, I am towing the boat with my truck/canopy and leaving the camper at home. My first mate is driving his 20' Chevy motor home (1980's era).

I bought a truck and camper to avoid the extra vehicle expense... so either a smaller camper or 1 ton Duramax is in order. My wife wants a motor home so maybe that's the way to roll... My truck isn't worth much used even though I've repaired/replaced everything except the tranny and transfer case. It really is a let-down to know it doesn't have the capacity I require.

If I keep the camper, a swing out trailer tongue may be best for the boat trailer... adding a 4 foot coupler section won't be difficult.