Axles

[calewjohnson]

Picked up a new trailer yesterday, Outback 323BH... Great trailer, took it out for a shakedown cruise last night, and everything was great...going to go out again this next weekend....this week though, I will be putting an Equalizer hitch on and pulling some weight tickets to get some try weights of the trailer....with that being said, it has 4400lb axles, which only allows me 800lbs of cargo....not very much for the amount of room this behemoth trailer has inside. My question, is it worth it to change the axles? Would Keystone tell me if the frame is able to handle the weight? I know that if I do the axles, I will need to change the springs, and the tires. Anything else?

Thanks,
Cale

Edit: corrected model number.

[FastEagle]

calewjohnson wrote:


While I know I cannot legally change the CCC of my trailer, it would be worth it to me in the long run to drop a some cash on changing the axles and what not. I have some homework to do, but I will know more once I weigh everything this weekend. It is funny, I have two printed brochures and the web site and all three give different weights listed for the same trailer.

Cale

You have all of the correct information. Before the manufacturer ships the trailer to the dealer they are required to update and install the certification label, tire placard and CCC label. The hitch weight is a value determined by the manufacturer. In the newest regulations it plays a significant roll in determining GAWR & GVWR. This is a brief description: The hitch weight (as published) added to the combined GAWR weight (s) MUST be equal to or greater than GVWR. Those figures must be valid at the time of first sale.

Once the new owner takes possession of the trailer it's their responsibility to insure none of the published load capacities are exceeded.

FastEagle

[ktmrfs]

Airstreamer67 wrote:
I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

cargo capacity by federal regulations and TT mfg does not change as you move weight to the tongue. It's still part of the trailer weight.

Federal regulations for travel trailers states that the mfg spec for GVWR of a travel trailer is the max weight on the axles and tongue combined, not the weight on the axles alone. so to see if your over the trailer GVWR you need to weight tongue and axles.

However, in determining what axles to use, yes, mfg sometimes do assume a certain tongue weight so axle rating may be less than GVWR. However, fed regs for travel trailers say that unloaded tongue weight + axle or tire rating (whichever is lower) must be equal or greater than GVWR. And GAWR must the the lower of axle rating or tire load rating.

this didn't used to be the case. Case in point. One of the trailers in our RV lot has a 10,900GVWR with two 4400lb axles. let's see, 10,900-8800= 2100 lbs on the tongue + what is transferred back to the axles. so to not overload the axles at GVWR you'd need something over 2400lbs on the tongue. Humm.... don't know of even a Class V hitch that would take that!!

[69_Avion]

calewjohnson wrote:

69 Avion wrote:

Airstreamer67 wrote:
I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

Many manufacturers do exactly that. That is the reason that a 9,500# GVW trailer has only two 4,400# axles. In the OP's situation he appears to gain only 200# for the tongue weight. Having only 900# for the carrying capacity of the OP's trailer is very low. He can't even fill the propane, water and groceries without being over. I don't know why the manufacturer didn't use 5,200# axles with the appropriate frame. The cost difference is almost nothing.

I used to build equipment trailers and I would always rate them at the combined axle weight rating, not including the tongue weight. I would do this because of the number of people who won't read the GVW and if they did, they may not care. I used it as a margin of error for the operator.

Which, while I know I cannot legally change the CCC of my trailer, it would be worth it to me in the long run to drop a some cash on changing the axles and what not. I have some homework to do, but I will know more once I weigh everything this weekend. It is funny, I have two printed brochures and the web site and all three give different weights listed for the same trailer.

Cale

I think you are going the right direction. Don't get too excited until you weight it. If you are reasonably close to the gvw then use it and see how it works.
By the way, ALKO axles are real good. They used to be called "Hayes" as I recall.

[jmtandem]

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

They already have. Two 4400 pound axles will not support a gross weight of 9000 pounds unless the tongue weight is calculated into the equation and deducted from the remaining coach weight. If the tongue weight is about 13 percent of gross or 1170 pounds and 20 percent of that is redistributed back to the trailer axles or about 230 pounds the math says 9000 gross minus 1170 for the tongue leaves about 7830 pounds for the coach on the axles plus the redistributed weight of 230 or so for a coach net no tongue weight of about 8060 pounds on two 4400 pound axles that have a combined rating of 8800 pounds. This works out to almost exactly the same number as the manufactuer provided and leaves no cushion.

[calewjohnson]

69 Avion wrote:

Airstreamer67 wrote:
I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

Many manufacturers do exactly that. That is the reason that a 9,500# GVW trailer has only two 4,400# axles. In the OP's situation he appears to gain only 200# for the tongue weight. Having only 900# for the carrying capacity of the OP's trailer is very low. He can't even fill the propane, water and groceries without being over. I don't know why the manufacturer didn't use 5,200# axles with the appropriate frame. The cost difference is almost nothing.

I used to build equipment trailers and I would always rate them at the combined axle weight rating, not including the tongue weight. I would do this because of the number of people who won't read the GVW and if they did, they may not care. I used it as a margin of error for the operator.

Which, while I know I cannot legally change the CCC of my trailer, it would be worth it to me in the long run to drop a some cash on changing the axles and what not. I have some homework to do, but I will know more once I weigh everything this weekend. It is funny, I have two printed brochures and the web site and all three give different weights listed for the same trailer.

Cale

[69_Avion]

Airstreamer67 wrote:
I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

Many manufacturers do exactly that. That is the reason that a 9,500# GVW trailer has only two 4,400# axles. In the OP's situation he appears to gain only 200# for the tongue weight. Having only 900# for the carrying capacity of the OP's trailer is very low. He can't even fill the propane, water and groceries without being over. I don't know why the manufacturer didn't use 5,200# axles with the appropriate frame. The cost difference is almost nothing.

I used to build equipment trailers and I would always rate them at the combined axle weight rating, not including the tongue weight. I would do this because of the number of people who won't read the GVW and if they did, they may not care. I used it as a margin of error for the operator.

[calewjohnson]

Airstreamer67 wrote:
I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

Probably them being conservative and if we do bend an axle, then they can absolve themselves of any responsibility.

[Airstreamer67]

I always figure that my cargo capacity is increased by the amount of tongue weight that the tow vehicle carries, net of weight transfer back to the trailer.

My question: why doesn't the manufacturer calculate this when they specify the cargo capacity? Perhaps because of the variables regarding exactly how much will the tongue weight affect the cargo capacity. But not doing so surely shortchanges the actual net cargo capacity of the trailer.

[jmtandem]

remember, with a WD hitch you transfer some TV axle weight to the trailer axles. In my case, with 1400lbs on the tongue, I add about 400lbs to the trailer axles

Good observation and something most folks don't think about. I use 20 percent of tongue weight back to the TT axles as a rule of thumb. Weighing is always better.

[Cecilt]

Cale, funny you should say you are anal retentive. My wife's nickname for me is Lana. You know what that spells backwards 😉

[calewjohnson]

Cecilt wrote:

bound4fl wrote:
Start flaming me.

To the OP load up take off and have a great time. 2 or 3 hundred pounds are not gonna make any difference, just don't take a full load of fresh water. Have fun life is too short to worry about everything.

Amen. I have the same 323bh as Cale. I am not going to stress over a few hundred pounds. IMO, all weights are conservative. If they weren't and we did overload we would constantly be breaking axles and frames. No way in he$$ can this TT only carry 1000 lbs. or the enviable it will break the second you pull it out of your driveway. I am about being safe but I also take calculated risks( I don't consider overloading a few hundred pounds a risk by definition) but that is the English saying. Go camping, have fun and don't stress over the weight.

Thanks Cecilt...quick background on me....I am severely anal retentive...I fly in the Navy and limits and procedures have been ingrained in me over time. I concur with the few hundred pounds over won't kill anything, but in the plane, I know that limits are for safety, but I still have a little something-something if I get into a precarious position. Airplanes are engineered and made to crash land and still walk away....now, RV's, all new territory.. Even though I have only been doing this for three years, I find that the best is from the folks that have tested and tried the limits of these items, hence the questions I have and the wanting to re-engineer the trailer. Thanks!

Cale

[ktmrfs]

FWIW I'm pushing the 4400lbs alko axles on one trailer. so I talked to my local parts guy about just what the 4400lb axles are. After he talked to Alko, best he could tell, and what he though earlier is that the 4400lb axles use a 5200lb tube, 10" brakes instead of 12" like the 5200lbs, usually 6 lug wheels and a spindle/bearing different from the 3500lb or the 5200/6000lb axles, and 2200lb springs.

As long as you have 4400lbs with 6 lug wheels rated for 2800+lbs you can switch to 5200lb axles using the same wheels and get more margin and bigger brakes. 225/75 LRE tires have a 2800lb rating so they have some margin.

curious if anyone else has info on what the 4400lb axles are composed of.

With almost 4400lbs on mine with the WD hooked up, the tubes still have lots of camber in them, and after 20K miles tires are wearing evenly. so I guess the axles have reasonable margin.

[Cecilt]

bound4fl wrote:
Start flaming me.

To the OP load up take off and have a great time. 2 or 3 hundred pounds are not gonna make any difference, just don't take a full load of fresh water. Have fun life is too short to worry about everything.

Amen. I have the same 323bh as Cale. I am not going to stress over a few hundred pounds. IMO, all weights are conservative. If they weren't and we did overload we would constantly be breaking axles and frames. No way in he$$ can this TT only carry 1000 lbs. or the enviable it will break the second you pull it out of your driveway. I am about being safe but I also take calculated risks( I don't consider overloading a few hundred pounds a risk by definition) but that is the English saying. Go camping, have fun and don't stress over the weight.

[calewjohnson]

ktmrfs wrote:

jmtandem wrote:

GVWR (lbs/kgs) 9000 / 4082.4

If your gross is 9000 pounds, then you will have about 1170 on the tongue (13 percent of gross). Be sure to get spring bars that are up to that amount. That leaves 7830 or so on the axles. If your axles are 4400 pound axles you have 8800 pounds axle capacity and the math aproximately says that leaves around 1000 pounds for all your stuff and water. Water is 8.3 pounds per gallon.

It becomes a little more than just changing the axles. Tires and springs are an issue as well. You will need to be able to have the carrying capacity in the tires to match the new axles, wheels to accommodate the new tires/pressures and probably upgraded springs.

remember, with a WD hitch you transfer some TV axle weight to the trailer axles. In my case, with 1400lbs on the tongue, I add about 400lbs to the trailer axles combined. So for the above case estimate that you would end up with about 8200 on the axles, or 4100 each axle. Close but under the axle rating and even more margin with the tires.

I did get a call from the dealer and my Equlaizer hitch is in....that will go on Friday, super excited about that... So, to sum it up...load it, weigh it and as long as I am good on trailer axle weights and truck weights...press on. I usually don't carry a lot of water, usually only 10 gallons for flushing. The way I have always done it, our TH has a 100 gallon fresh water tank, I was always a little leery of putting almost 900lbs of water on the crappy looking straps holding the tank to the bottom.

Cale