3500# > 4400# Dexter Axle Upgrade

[Doppleganger]

We have a 2020 Apex Nano 187RB, Outfitter and Off-Grid packages. So, with all that added weight, we only have about 450lbs of cargo capacity with a 3800# GVWR. Haven't weighed it yet, but I'm sure we're overweight.



I downloaded the axle spec sheet from Dexter and was comparing the 3500# axle (which is what we have) with the 4400# axle. It appears they both use the same bearings and the spindles seem to be identical on the two axles. The only difference appears to just be the diameter of the axle tube. I'm hoping to be able to keep the 5x4.5 hubs and brakes of our current axle, and just transfer everything over to the 4400# axle, with a little heavier leaf springs. Don't want to go too much stiffer, as it would shake the TT around more than needed.


Has anyone one this upgrade before? Should be something I can do in the driveway with my plethora of floor jacks and jack stands.

[SeaDog]

Sounds like a great project take pics and let the forum know how it goes there may be others in your same situation that could upgrade without buying a new rig good luck

[Mike134]

I've changed an axle but not upgraded. Really easy to do. I'm guessing you'll need new U bolts.

[GXPWeasel]

Agreed, this sounds like a good project, and one that is also easily doable, with some mechanical knowledge, a good tape measure, and some patience.

[chaps2018]

Curious-are you expectIng the trailer GVWR to increase with the additional capacity provided by the new axle?

[BriaBeck]

Obviously it would...

[Mr Towed]

Originally Posted by BriaBeck

Obviously it would...

Not necessarily, from a legal standpoint. Things like the frame size are also factors in the GVWR. Certainly you will help your chances of not having weight related axle issues but if you actually wanted to be considered to have a higher GVWR that might take some doing, and I’m not sure what that would involve.

[BriaBeck]

Well, I'm only going to stick one foot into that mud hole... The "Legal" world and the "Real" world are often times independent of each other. If you don't believe that, just look at how the manufacturers are allowed to spec the axle/tire combinations on some of these rigs!!! Might be "Legal"... but sure as Hades isn't "Real World"!!!



I'll bet that if you compared the frame rail size on the OP's camper to the next bigger/heavier/more opulently equipped model, I'll just bet that they are the same size. Maybe not... but chances are that they are the same.



The OP's GVWR was likely limited primarily by the axle specified by the manufacturer of the camper.

[hobienick]

Originally Posted by BriaBeck

Obviously it would...

As you brought up in a later post, there is more to this than just the axel. The frame is a key factor. Not only the thickness of the material used, but also the overall design.

Part of the real world is cost. If it saves money to use the same material as the higher weight trailers but less of it, they will usually do that. Especially since it saves weight. Along these lines FR probably uses that same frames on multiple trailers so it may be OK.

Basically, you need to understand the system, not just a component. You can drop a 350 into a Jeep CJ5. If you don't upgrade the driveshaft it will not turn out well. I'm not saying it can't be done. Just make sure you are looking at everything.

[Mr Towed]

Originally Posted by BriaBeck

Well, I'm only going to stick one foot into that mud hole... The "Legal" world and the "Real" world are often times independent of each other. If you don't believe that, just look at how the manufacturers are allowed to spec the axle/tire combinations on some of these rigs!!! Might be "Legal"... but sure as Hades isn't "Real World"!!!



I'll bet that if you compared the frame rail size on the OP's camper to the next bigger/heavier/more opulently equipped model, I'll just bet that they are the same size. Maybe not... but chances are that they are the same.



The OP's GVWR was likely limited primarily by the axle specified by the manufacturer of the camper.

Totally agree, and agree that it is a worthwhile upgrade.

However the GVWR, in itself, is a legal term. I remember hearing that certain years the F-250 equipped a certain way was almost exactly the same as the F-350, basically with de-rated GVWR for legal reasons to stay under 10,000 pounds. But even in that case even if it is literally the exact same truck with a different badge doesn’t mean you can change the GVWR by changing the badge (or any other modification for that matter).

So while this modification will certainly improve the capabilities and safety factor of the trailer in question, I’m not sure what, if anything, can be done to increase the actual GVWR, which I guess would require a new capacities placard. If anyone knows that I’d love to know and I feel it would contribute to this conversation. I am curious because I have actually considered an axle upgrade myself, just to increase the “real world” cargo capacity.

[Asrabbit]

I had to do this same upgrade because my 3500# axle just could not hold the weight, and no I was not over weight at all, so no need to ask about that.

The 4400 # axle works with existing parts with the exception of the U bolts and plates.

My issue was that my 3500 # axle would flatten out and a tire on one side leaned in at the top. Again, I was not over weight, unless it was over weight from the factory, (which it was not). This happened when I first picked up the trailer with nothing in it. The dealer replaced the ordinal 3500 # axle with another 3500# one, which did the same thing. The 4400 # was a great improvement and I have never had issues with it.

[Asrabbit]

I should have added that the 4400 # axle is a 3 inch tube which is larger than the 3500 # axle. That is why you need the new U Bolts and plates. I changed out the axle my self. It was a very easy job. Lippert supply the axle to me as a warranty item.

[Larry-NC]

Originally Posted by Mike134

I've changed an axle but not upgraded. Really easy to do. I'm guessing you'll need new U bolts.

I'm thinking that new leaf spring brackets will be needed, with wider hole spacing to accommodate the new U-bolts. Probably a Dexter catalog item.

But I can't help wondering if that's the only thing that's needed to increase the safe GVW rating. What if the frame members are not sized to accommodate the increased load and they buckle on the first pothole the OP hits?

[BriaBeck]

Originally Posted by Larry-NC

I'm thinking that new leaf spring brackets will be needed, with wider hole spacing to accommodate the new U-bolts. Probably a Dexter catalog item.

But I can't help wondering if that's the only thing that's needed to increase the safe GVW rating. What if the frame members are not sized to accommodate the increased load and they buckle on the first pothole the OP hits?

Well, he's already overweight as he stated... they haven't buckled yet. The new axle isn't' going to change anything with that.



Again, those little $0.10 brackets that are welded onto the frame to attach the axles likely get used on every frame, from the lightest to the heaviest. I would be more concerned with the quality of the welds by far, rather than the strength of the bracket.



Me thinks some overthink things a bit and worry needlessly....

[Las Cruces]

On my Cherokee I replaced the axles 7K, up graded the brakes and added a Dexter E-Z Flex Equalizer system. I've never had a better ride with less worry.

[Doppleganger]

I'm just guessing we're overweight, since the dry weight of this doesn't leave much room for cargo. Haven't scaled it yet, though. But, I do know, there was someone else who asked FR about the chassis used on the 187, and a larger unit with a slide out, and they were indeed the same chassis. The other unit had a 4400# axle, and FR said that the 187's chassis would be able to support the weight when paired with the larger axle. Going from a 2 3/8" to a 3" tube will add strength and obviously the u-bolts and plates will need to change, and I'm wondering if going with slightly stronger leaf packs would be a good idea as well? I have been having tire clearance issues, which I'm pursuing a fix under warranty, as it's more than just a cosmetic problem. I'll add some pics here. The tire rub on the support happened at slow speeds, usually when corning in a neighborhood where the streets are not parallel with each other, and there's a grade next to a flat road, or maybe a slope for drainage, or something like that, that causes the suspension to flex.


Mechanically, this isn't an issue for me to do, I've got the tools to accomplish it, and have pulled an axle off my cargo trailer, and Bronco in the past.


Thanks for the info everyone!

[Larry-NC]

Originally Posted by Doppleganger

I'll add some pics here.

Those are interesting tires. I'll bet they are noisy.

I am not a tire expert, but I would not have expected to see tires like that on a non-drive axle.

[TheWolfPaq82]

Originally Posted by Larry-NC

Those are interesting tires. I'll bet they are noisy.

I am not a tire expert, but I would not have expected to see tires like that on a non-drive axle.

Or mudflaps.

[Doppleganger]

Originally Posted by TheWolfPaq82

Or mudflaps.

Mudflaps to help protect the plumbing. Used u bolts to clamp them to the 2x2 lateral tube. Pretty solid.

[Doppleganger]

Coachmen is now using 4400# axles on the 187rb.