Replicating a HDPP Possible?
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 26
Likes: 10
From: Lake Forest, CA
Modifying your truck cannot raise it's legal GVWR. Re-certifying at a higher GVWR is possible, but it would require engineers, lawyers and testing and would probably cost quite a bit more than a new truck. So I suggest you forget about that route.
The obvious answer is buy another truck... but you DO NOT WANT TO BUY A NEW TRUCK. Well how about used one! LOL
There is a legal way to increase your payload but not your GVWR. Simply take stuff off the truck that you don't need.
The good news, your 2019 Max Tow likely has the same frame as the HDPP and it already has a 4050 rear axle / springs. Properly balanced you could put 2,000 in / on your truck and not exceed your axle ratings. Since you likely already have the HDPP frame (craw under and check) I see no issue from a flexing / breakage perspective. The only issue is that the softer springs of the Max Tow vs the HDPP will not control the weight as well. To fix this you could get the 600 pound / inch front coils from and HDPP and the HDPP rear spring pack (or, it's easier, cheaper and likely more effective to just add SumoSprings or equivalent in the rear). Get the HDPP shocks as well. That set up wont be legal beyond your current GVWR. However, it should handle the load as well as an HDPP from a physics perspective. I'm assuming that the sway bar on the two are the same but you may want to check part numbers to be sure. The HDPP sway bar may be thicker, if so get that too. Given that your truck is already as close as it gets to an HDPP without being one, it shouldn't be hard. For you, it should just be Springs, shocks, sway bar, wheels, tires. You still wont have the rear axle but I don't think you need it for a well balanced 2,000 pound payload.
The obvious answer is buy another truck... but you DO NOT WANT TO BUY A NEW TRUCK. Well how about used one! LOL
There is a legal way to increase your payload but not your GVWR. Simply take stuff off the truck that you don't need.
The good news, your 2019 Max Tow likely has the same frame as the HDPP and it already has a 4050 rear axle / springs. Properly balanced you could put 2,000 in / on your truck and not exceed your axle ratings. Since you likely already have the HDPP frame (craw under and check) I see no issue from a flexing / breakage perspective. The only issue is that the softer springs of the Max Tow vs the HDPP will not control the weight as well. To fix this you could get the 600 pound / inch front coils from and HDPP and the HDPP rear spring pack (or, it's easier, cheaper and likely more effective to just add SumoSprings or equivalent in the rear). Get the HDPP shocks as well. That set up wont be legal beyond your current GVWR. However, it should handle the load as well as an HDPP from a physics perspective. I'm assuming that the sway bar on the two are the same but you may want to check part numbers to be sure. The HDPP sway bar may be thicker, if so get that too. Given that your truck is already as close as it gets to an HDPP without being one, it shouldn't be hard. For you, it should just be Springs, shocks, sway bar, wheels, tires. You still wont have the rear axle but I don't think you need it for a well balanced 2,000 pound payload.
Weird how its possible to exceed GVWR but still be under the front and rear GAWR. Why do manufactures do this?
Senior Member
Joined: Sep 2018
Posts: 280
Likes: 51
From: Michigan
Weight Distribution
Just checked and YES it does have the HDPP frame.... adding up GAWR is a combined 7700 for my truck... Really think its dumb that the combined GAWR is 650lbs over the GVWR (7050).
Weird how its possible to exceed GVWR but still be under the front and rear GAWR. Why do manufactures do this?
Weird how its possible to exceed GVWR but still be under the front and rear GAWR. Why do manufactures do this?
I can place 100% of my remaining payload directly over the rear axle and just (but not quite) max it out.
On the other end of the spectrum, If much more than a third of my payload is over the front axle, I'd be over on the front. This isn't really practical, because the hood is way to flimsy to support much weight, so anything in the cab would put load on both the front and rear axles.
In practical application, this is a people [cab] vs cargo [bed] loading difference.
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 26
Likes: 10
From: Lake Forest, CA
Because they don't know where the weight will be placed in the vehicle when loaded.
I can place 100% of my remaining payload directly over the rear axle and just (but not quite) max it out.
On the other end of the spectrum, If much more than a third of my payload is over the front axle, I'd be over on the front. This isn't really practical, because the hood is way to flimsy to support much weight, so anything in the cab would put load on both the front and rear axles.
In practical application, this is a people [cab] vs cargo [bed] loading difference.
I can place 100% of my remaining payload directly over the rear axle and just (but not quite) max it out.
On the other end of the spectrum, If much more than a third of my payload is over the front axle, I'd be over on the front. This isn't really practical, because the hood is way to flimsy to support much weight, so anything in the cab would put load on both the front and rear axles.
In practical application, this is a people [cab] vs cargo [bed] loading difference.
Member
Joined: Jan 2018
Posts: 11,256
Likes: 1,770
From: Memphis, TN, Earth, Milky Way
Thread Starter
Junior Member
Joined: Sep 2019
Posts: 26
Likes: 10
From: Lake Forest, CA
I have not studied mechanical engineering academically. That is why I am asking these questions in hopes someone can respond that can provide constructive criticism, which people have. I do not appreciate the passive aggressive comment.
5 Year Member
Joined: Jun 2019
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“Wouldn’t it be great to swap in a 6.0 PSD into my 2.3 Ranger?”
”I guess so, Chief, but you just wiped out your payload cap and any semblance of utility with the weight of the axles and drivetrain piled onto that skimpy frame. But, it rattles a lot!”
Everything. That’s why these vehicles are tested years before they’re a twinkle in an owner’s eye. Bearings, hubs, frame, anything holding the vehicle together. You name it. I’m watching this episode of NOVA about why bridges collapse right now. The I-35 bridge in Minneapolis collapsed because a gusset plate was 1/2” thick rather than a full 1” thick. Too much weight on something that couldn’t handle it plus Mother Nature at work. It may last some time, but when it decides not to...
5 Year Member
Joined: Jan 2017
Posts: 905
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From: Quebec, Canada
Well, you got your answers already. The mechanical engineer I am says your thinking makes sense (as a constructive comment this time), however GVWR can’t be increased, even if you do all HDPP modifications, because the limitation is then a legal one.
Sorry buddy, to achieve that legally and safely, you’ll need a new HDPP truck. I’ve been in the same situation and made the move.
Sorry buddy, to achieve that legally and safely, you’ll need a new HDPP truck. I’ve been in the same situation and made the move.
Senior Member
Joined: Nov 2017
Posts: 901
Likes: 259
From: PA
Just checked and YES it does have the HDPP frame.... adding up GAWR is a combined 7700 for my truck... Really think its dumb that the combined GAWR is 650lbs over the GVWR (7050).
Weird how its possible to exceed GVWR but still be under the front and rear GAWR. Why do manufactures do this?
Weird how its possible to exceed GVWR but still be under the front and rear GAWR. Why do manufactures do this?
