Payload increase from axle and suspension upgrade?

[Alabama Mud Machine]

You can upgrade all you want, but that frame and bed are going to still be your limiting factors.

Sponsored

 

[PyrPatriot]

This is basically true everywhere. The placard is certified and can't be changed.

It CAN be done, just pricey

https://www.worktruckonline.com/145897/re-rating-gvwr-why-and-how-its-done

Also I'd want it more for my own peace of mind, not for any particular legality perspective. Even if by the book your placard says one thing, at trial your expert convinces a jury that reality has it higher.

For example, doing some searching it looks like Dana 60 axles have a GAWR of up to 6500lbs. That is double the Dana 44's 3100/3750 (front/rear). So say on the conservative side you have a GAWR of 5500/6000 with a Dana 60. For my JT Max Tow the GVWR is 6250, combined GAWR is 6850, 600lbs difference. If a combined GAWR would yield 12500, Load range E tires generally support 3200lbs each max, that's 12800lbs of support. A JT weighs about 4700-5000lbs. 12500-5000 = 7500lbs left. But that weight isn't what is on the axles, that 5000lbs includes the weight of axles, tires, etc. So with Dana 60 axles you should have AT LEAST 2500lb payload. I mean, F250s have 4500lb payloads, it's gotta be based on factors besides the engine. I'm not saying the JT with Dana 60s could have 2500lbs in its 5ft bed, but with Dana 60 axles surely you could load more up on the roof rack (reinforced/attached to the body/frame somehow) and bed overall. I'm not saying the engine could pull a 2500lb payload. But the vehicle could physically withstand having it and rolling along the road.

Or am I just completely wrong here?

 

[smlobx]

It’s threads like this that have me wondering if the Jeep engineers ever come onto this site for a good laugh....

 

[ALVagabond]

It CAN be done, just pricey

https://www.worktruckonline.com/145897/re-rating-gvwr-why-and-how-its-done

...

Or am I just completely wrong here?

I think you're technically correct. The article implies that it's really only done for commercial vehicles. And it's important to note that it's done by the OEM and changes the VIN. It's not something you can do yourself by throwing a suspension upgrade and/or axles.

 

[PyrPatriot]

It’s threads like this that have me wondering if the Jeep engineers ever come onto this site for a good laugh....

I wish they would. If only for folks like me to knkw they are wrong

 

[velogeek]

It CAN be done, just pricey

https://www.worktruckonline.com/145897/re-rating-gvwr-why-and-how-its-done

Also I'd want it more for my own peace of mind, not for any particular legality perspective. Even if by the book your placard says one thing, at trial your expert convinces a jury that reality has it higher.

For example, doing some searching it looks like Dana 60 axles have a GAWR of up to 6500lbs. That is double the Dana 44's 3100/3750 (front/rear). So say on the conservative side you have a GAWR of 5500/6000 with a Dana 60. For my JT Max Tow the GVWR is 6250, combined GAWR is 6850, 600lbs difference. If a combined GAWR would yield 12500, Load range E tires generally support 3200lbs each max, that's 12800lbs of support. A JT weighs about 4700-5000lbs. 12500-5000 = 7500lbs left. But that weight isn't what is on the axles, that 5000lbs includes the weight of axles, tires, etc. So with Dana 60 axles you should have AT LEAST 2500lb payload. I mean, F250s have 4500lb payloads, it's gotta be based on factors besides the engine. I'm not saying the JT with Dana 60s could have 2500lbs in its 5ft bed, but with Dana 60 axles surely you could load more up on the roof rack (reinforced/attached to the body/frame somehow) and bed overall. I'm not saying the engine could pull a 2500lb payload. But the vehicle could physically withstand having it and rolling along the road.

Or am I just completely wrong here?

Somewhat correct.

Up-rating a truck means the certifying company is liable if there is an issue that arises as a result of an inappropriate weight rating and serves nothing but the legal purpose. Normally, these companies are either up-fitters guaranteeing their own final product or will only work with common commercial vehicles in common commercial modifications. You swapping a Dana 60 off some 1980's one-ton is not a configuration they are going to certify as a one-off. There will need to be some degree of reputation and trust between the person and whomever modified the vehicle because again, it's all about legality and not what a vehicle is functionally capable of.

To be honest, I'm not even sure this is possible for a Class 1/2 truck (Gladiator being an extremely lightweight Class 2 I believe). Lowest I've seen this done was at the F-450 level when doing a SRW conversion and it's generally done to skirt legal requirements (e.g. seat belts for passengers in a van) or reduce taxes (lower GVWR = lower taxes).

While a Dana 60 may be able to hold 6000lbs, not every Dana 60 can hold that weight. Some are barely larger tubing than the Gladiator's D44. You would need to determine the GAWR of that particular model and then assume you've lost some due to fatigue if it's an older axle.

The powertrain is the least concern in all of this because it's intended to move over 11,000lbs. Doesn't matter if the payload is in the bed or on a hitch, the engine won't know the difference. This of course assumes you aren't running 35's on 3.73 gears and have regeared to get somewhere near what the Max Tow 31.5" and 4.10 combo puts you.

The greatest issue in all of this will be the suspension (arms and mounts) because they were not intended to hold this weight. You will need to reinforce the shit out of the frame around the spring perch all the arms and upgrading the steering wouldn't be a bad idea either.

 

[ACAD_Cowboy]

Mind you, you will never be heavier than the door tag, legally. Yes you could monkey around and shovel in a dana 60/80 setup and be bad-ass but then you'll be upgrading the shock and springs and steering gear and box and pump and then frame reinforcements and before you know it you could have just started with a Ram 45/5500.

Pause and take a deep calming breath and ask yourself: Self, how many axle shafts have I fractured since kindergarten? How many axle tubes have I bent up since high school?

If the answer is none, rejoice. You are not required to evolve past dana 30 or 44 due to living outside your means.

 

[PyrPatriot]

The powertrain is the least concern in all of this because it's intended to move over 11,000lbs. Doesn't matter if the payload is in the bed or on a hitch, the engine won't know the difference. T

But, wouldn't there be a difference in strain from moving a concentrated load vs a distributed load? A trailer might weigh 7650lbs but it's spread across a greater surface area than in a 5ft bed.

you could have just started with a Ram 45/5500.

But it would not be a Jeep

 

[velogeek]

But, wouldn't there be a difference in strain from moving a concentrated load vs a distributed load? A trailer might weigh 7650lbs but it's spread across a greater surface area than in a 5ft bed.




But it would not be a Jeep

No it doesn't matter as long as other factors like traction remain constant. The engine/transmission/transfer case aren't going to know the difference because they bear no load. Their sole purpose is to deliver torque to the ring gears and the only components that will know the difference are those which are load-bearing like the wheel hubs and axle shafts if not full float.

You would also need to keep in mind that putting weight behind the axle puts an additional factor of weight on the rear axle. Much like how you can get a 20,000lb trailer to have a 500lb tongue weight with proper loading, the axle is a lever. The further from the axle the weight is, the larger the factor.

So if you are sticking 2000lbs behind the rear axle, you're likely carrying much, much more than that on the axle itself.

 

[Blade1668]

This thread reminds me of the M35 family of vehicles AKA the 2.5 ton trucks it's rated for 2.5 tons off road, on "improved" roads it was rated for up to 5 tons.... Speed was not really consideration, over 45 mph or faster was not planned for. I do want one chopped back with a "trailer" bed but not likely to happen or need. . now if I hit the lottery "Oh H### yeah. it would probably be a D.D. for me.

 

[spazzyfry123]

It’s going to cost a lot of scratch for peace of mind. If you’re just looking for a “little” beyond the door placard, why don’t you just get a small, little trailer?

Or is this thread just an exercise of conversation?

 

[PyrPatriot]

It’s going to cost a lot of scratch for peace of mind. If you’re just looking for a “little” beyond the door placard, why don’t you just get a small, little trailer?

Or is this thread just an exercise of conversation?

Just for the exercise of conversation. And really my own curiosity. People upgrade axles to keep them from snapping during activities like desert racing, sand crawling, or when they put on 40” tires. So they are clearly stronger, and I want to know how does that translate to the truck aspect of the Jeep

 

[Ichthus]

Just for the exercise of conversation. And really my own curiosity. People upgrade axles to keep them from snapping during activities like desert racing, sand crawling, or when they put on 40” tires. So they are clearly stronger, and I want to know how does that translate to the truck aspect of the Jeep

the best answer is that it makes your truck more capable of accomplishing the work it was certified to do without breaking or causing liability issues...but does not truly increase the limits. Generally those people upgrading axles are doing so to avoid catastrophic failure caused by the increased loads from significantly larger and heavier tires, and terrain impacts. I think there’s a big difference between limiting susceptibility to trail damage and risking legal liability on the road

 

[Alabama Mud Machine]

Just for the exercise of conversation. And really my own curiosity. People upgrade axles to keep them from snapping during activities like desert racing, sand crawling, or when they put on 40” tires. So they are clearly stronger, and I want to know how does that translate to the truck aspect of the Jeep

It translates the exact same as it does for anything smaller than a 3/4-ton truck... Simply strength in handling more power, torque, and larger tires from beefier components. And no affect on payload, because the rest of the vehicle itself simply cannot handle any additional payload in stock form (factory frame/body, suspension, etc...).

 

[PyrPatriot]

It translates the exact same as it does for anything smaller than a 3/4-ton truck... Simply strength in handling more power, torque, and larger tires from beefier components. And no affect on payload, because the rest of the vehicle itself simply cannot handle any additional payload in stock form (factory frame/body, suspension, etc...).

Really? I would have NEVER thought the frame is the ultimate limiting issue. I figured axles and suspension would give first, as the bed is steel.

Well, there goes my vision of dropping in a bigger engine/transmission, new axles, upgrade suspension, and having an overlanding Jeep truck that can comfortably bring 500-1000lb of gear/food/gas/water after adding racks, bumpers, winches, external armor, etc. as it stands my Max Tow only would allow 1000lbs of gear, supplies, and occupants after adding bed rack, roof rack, steel bumper, and winches.

And when occupants are half that, well 500lbs isnt a lot of food, water, and fuel for extended trips into the wilderness

Sponsored