payload capacity

short story to important question:

so I was havin a discussion with my dad the other day and talk in about how I'm gonna eventually swap out my leaf springs for better ones (mainly for lift but also the improved ride quality). During the conversation I mentioned how the new springs should increase the payload capacity of my truck. At this point he made an interesting argument that I hadn't thought of and have never seen discussed on here anywhere:

what is the payload capacity of our rear wheel hubs? this is important because the payload capacity of a truck is not just determined by the leaf springs (or rear suspension setup in general) but also by these hubs and as he pointed out, while there is a way to make the springs from a 1 ton chevy fit (or most of them) that wouldn't mean that our trucks could cary 1 ton of weight... the hubs probably can't take that

so the question: anyone know the rating on our hubs? I tried a google search and couldn't find anything..?

 

i would guess probably whatever the overall payload capacity of the truck is. same with everything else on the ass of the truck. there's also a reason why 1-ton domestics have heavier everything else underneath even if the body is the same.

 

hubs….
frame….
bed….
shocks….
springs…..
lugnuts…….
condoms…….


you won't know until you break it!!!!!!!!!

 

I remember reading it somewhere....isnt it like 1000 or 1200 or something?

 

I think y'all took my OP with the wrong connotation... I'm not saying my dad was wrong, I'd just kinda be surprised that the payload of the hubs is really only what the truck is rated at... I know that the payload capacity is based off all the parts on the rear end and that the hubs (and other parts) are going to limit it. My question is, does anyone have the exact specs on the hubs in our trucks? Like i said, I'd be surprised if they were truly only rated to handle the stock payload capacity rating and that toyota hadn't actually limited that with our underrated springs....

also, I didn't post this thread with the intention of upping my capacity, I was just curious. I know that many of the aftermarket spring packs have a higher capacity than our stock springs and I'm just curious to know what the true limits of my truck are in case I ever do need to haul something.. which I basically never do now..

 

this is really where my question comes from... I and many others have definitely overloaded our trucks and had them riding on the bumps to where the leaf springs were obviously outdone, but they still rode fine.. minus the harsh rear end obviously...?

 

my response was just meant to show a lack of surprise. as much as i love mine, it was designed wholly within a very specific set of parameters. as much as they cost, toyota isn't going to put more into them than they feel is necessary for the specific task. so agreed.

i'm guessing the beefier aftermarket spring packs are made, at least partially, to combat the fatigue of stock springs and therefore the "taco lean"?

 

i'min the same line of thinking as both of y'all^^ i'm not so much wanting to know for reasons of even getting to their capacity, I'm just curious to know what my true capacity would be with new springs in, obviously accounting for what the springs could take.. but sense there's no break down on each part there's really no way to tell I guess

 

I know of at least one Tacoma with premature rear axle bearing failure from being loaded on the bumpstops only occasionally for short distances. The rest of the time it was loaded within the payload rating. At 80K it needed the rear wheel bearings replaced. What it would take to actually bend or break something (frame, axle housing, springs), I don't know. It would be foolish to push one of these trucks to the point of failure.

The stock springs could be a bit stronger, but installing springs that make the truck appear to be level when at max payload eliminates a warning system of sorts. When the truck is squatted down and the nose is light, you know it's time to stop loading it with bricks. If you don't have that type of warning you risk failure of some other component, hopefully not at high speeds.

Toyota had a problem with their chassis cabs back in the 80's. From talking with a dealer mechanic from that era, the problem was that they were selling the chassis cabs to RV companies, and the RV companies were building them so heavy that they were overloaded before they were even packed for a camping trip. We are talking about wheels falling off the rig on the freeway. A recall was issued and the rear axles were upgraded to full floaters, but the root of the problem was customer (conversion company) abuse. Toyota no longer builds chassis cabs, that is one reason why.

A 3/4 ton truck has a full floating rear axle and a thick steel frame. Trying to treat a Tacoma with heavier springs the same way you'd treat a 3/4 ton truck is a very bad idea. A trailer with a good set of brakes on it is a better idea.

There is a 4Wheel camper forum on the web somewhere. It's easy to find with Google. Those guys are overloading there trucks by probably 300-500 pounds. I see them talking about extra springs, airbags, etc. I wonder about axles and brakes, longevity and safety. It's something I will not do. If you cause a wreck and hurt someone, regardless of any spring and brake upgrades, and your truck is 500 pounds heavier than the sticker on the door says it can be, you have a very big legal problem.

 

^^ very good point about the warning system!! something we've used in past trucks and I just hadn't thought about here... but again.. I really didn't start this thread because I plan to OVERLOAD or even reach the TRUE capacity of my truck, I just wanna know what it is, mostly for curiosities sake...

 

I'm trying to figure out what to do with upping the capacity of the the rear springs also.


I'm hauling right now, and the stock can't handle it. The trouble is if you get into the heavy duty leaf packs for loads like Dakars, you get too much lift, Dakars are about 2 3/4 inch lift. Great load handling, but that lift limits the down travel of whatever shock you have.


These expos and Deavers, they aren't load carriers, they're soft from what I've read. An AAL, I've heard they add another 500 lbs load capacity to the truck, depending on which AAL. I need load carrying, but as of now I can't figure out if the solution is an AAL or these Timbren hybrid airbags/bumpstops. The Timbren has been recommended and I'm leaning towards that.

 

this is EXACTLY (or partially) why I started this thread... some people are hauling with these trucks and trying to "up the payload" but are only upgrading their leaf packs.... while they seem to not be having a problem with wearing out the rear bearings I wanna know why.. Are our rear ends TRUELY rated at a much higher capacity and only limited by toyota with crappy springs or are people overloading their rears by putting on bigger springs that can take the weight while not upgrading anything else??

 

1280lbs for double cab SB 2014 model.
OP, what are you planning to haul with the truck? I would think our springs would fail and hit the bumpstops before you even have to worry about the hubs.

 

Here is an example of capacity.
http://www.youtube.com/watch?v=1yIR_5OSVXs

 

I've loaded one yard of gravel and moved it 10 miles a few times. That's about 2,700 lbs. Def not good for the truck, but it will do it. Just drive nice and easy. DCSB non tab.

 

Ive had 1900lbs of stone in the back of mine and it wasnt riding on the bumpstops, the AAL helped obviously.

So lets say that you have your truck loaded to max payload, 1200-1400lbs, whatever it might be.
When you start hitting bumps in the road, the force being put on the suspension system increases and decreases as the truck moves up and down. So in effect the load put on the truck is intermittently more than whatever you are carrying. (jump up and down with a full backpack) With that being said, the engineers at Toyota have to put components that are capable of stresses beyond the maximum recommended payload. If they didnt, you would bust your bearings a mile down the road on your first load. Now what are the maximum tolerances of all the components? Like Mick478 said, you wont know until you break it.

 

I believe the limiting factor on load capacity is not the hubs, wheels, tires, springs, etc.
It is the braking system. Toyota has calculated the maximum stopping distance with the brakes at full payload.
If you put 1000 lbs more than their max, your distance stopping from 60mph has changed( if you can stop at all). And if you have a trailer, they want it to have its own brakes. Try stopping with an extra 5300 pounds behind your butt.

 

I believe you guys are all so full of it yours eyes are brown. The single cab Hilux has a load capacity of 1390Kg, or 3064 pounds.

http://www.toyota.com.au/hilux/features/car-performance/payloads

Having had my tacoma side by side with a hilux, it is indeed the same axle, brakes, and bearings as the tacoma. It does, however, have a fully boxed frame all the way back and higher load capacity springs than a stock taco and a real metal bed.

 

Almost the same truck. The frame is identical from the cab forward, very similar curb weights, including suspension and brakes. This is interesting to note, because if one were to build a "severe use" tacoma it would be pretty easy. Plate the frame from the cab to the tail, add higher load capacity springs or airbags, and do work.

 

In my line of work we use MAWP (Max Allowable Working Pressure) on a lot of our equipment. It is usually set at about half of the actual failure point of the equipment. I would think that automotive engineers use the same sort of system. That being said, I wouldn't be afraid of adding some airbags to the rear suspension and carrying loads above the max capacity within reason.