Is your axle under slung or over slung?

cruza driver

Hercules
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On our Outback Expanda our axle is over slung yet in the brochure it states that Outback Expandas should be under slung :confused:

We have a 16.49-3 Outback which is a Dec 2010 build.

Today on the freeway I followed a brand new 2011mdl the same design as mine it had an under slung axle :(

I did ask my dealer about this the last time I was there yet they couldn't really offer any answer! I might have to give head office a call.
 

chartrock

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My 14-44-3 Outback (November 2010 build) is overslung. I toyed with the idea of underslinging it but I can only just reach the clips to unlatch the pop top now. If I swapped the axle it would raise the body by another 4"-5" and I would have trouble unlatching the top. I still may switch it, but I doubt it.

Paul
 

Moto Moto

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I also researched this online and through my dealer. So please excuse my third hand explanation, it may be a little off.

Its all to do with the axle rating and keeping the tow hitch ADR compliant.

The dual axle models have 2*1.5t axles and smaller leaf packs, therefore to get the 'outback' height they are underslung.

The single axle models generally have the 2t axles and much beefier/thicker leaf packs, there fore they are at the 'outback' height already and keep the over slung axle. If you under slung the axle on these models they would not meet standard height requirements, not sure if this is true, just what i was told. Bet they would match a typical 4wd with 50mm lift though.

I read elsewhere the camper models have the same issue, and if you had a swan for example with all the fruit, you would need to upgrade to the 2t axle and associated thicker leaf pack and an over slung axle to keep the hitch height legal. But these models also have a 50mm spring hanger to get some more height, just not sure if the Expanda's have this as well.

Now to add to the confusion, i have noticed some dealers offer the standard touring model with a few hundred dollar option to get the axle underslung to turn it into a rough road mid spec model. Much cheaper than the full outback option. They must be able to do this because the smaller diameter wheels keep the hitch height within regulations.

Have i confused you all yet?

My head hurts.....................:confused:
 

Bushman

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Well! to say the least, you can imagine I was a little more than don't be rude off when we got our Expanda "OUTBACK" home to find wasn't underslung, when the brochure states they are :mad: I phoned the dealer and asked why, he then mentioned coupling height regulations bah bah bah.

HHHMMMM my camper was underslung, I've seen a Sterling "Outback" Pop-top it was underslung and recently saw a StarCraft (full van) "Outback" also underslug :confused:

And as Cruza said sighted a current model brand new the same as mine and his, yep you guest it "UNDERSLUNG" :confused:
 

cruza driver

Hercules
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underslung.

The single axle models generally have the 2t axles and much beefier/thicker leaf packs, there fore they are at the 'outback' height already and keep the over slung axle. If you under slung the axle on these models they would not meet standard height requirements, not sure if this is true, just what i was told. Bet they would match a typical 4wd with 50mm lift though.





Have i confused you all yet?

My head hurts.....................:confused:

Yes my head hurts too! :rolleyes:

I would be curious to see where the hitch is located whether its on top of the drawbar or at the bottom after it has had a springover done by Jayco.
 

Moto Moto

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Has any one with an overslung axle tried to calculate the height of their hitch if they were to do an underslung conversion?

It would be easy to calculate the new hitch height if you underslung the axle (by adding the leaf pack thickness and the axle thickness to the existing hitch height, on level ground) . Wonder what that new measurement would be and if it was within legal tolerances?

There are two recent Jayco discovery outbacks in my area. The twin axle model is underslung, the single axle model is overslung, matching my theory before.
 

wizzerwazza

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Sep 20, 2010
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my 06 expanda outb ack (16ft) is overslung. for me its pretty well the perfect height for my vehicle. wouldn't want it any higher.

wizzer
 

Moto Moto

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Today i ordered a spacer/packer that raises the tow hitch on the van by 50mm. Jayco Canberra sell these for about $150. I have asked them to fit one to my Expanda ready for delivery time.

I plan on doing a 50mm lift on my Patrol soon so thought i would get this done now considering i am getting an "overslung outback". I'm worried to hitch height will be too low standard and i don't really want to run a drop hitch thingy.........................
 

chartrock

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G'day Moto. I have had the local Jayco dealer at Tweed Heads fit the 50mm block (actually 2 x 25mm blocks) to my tow ball receiver which means my draw bar has dropped by that amount and raised the rear of the van which was my aim. But as I showed in aprevious post, my Hayman Reese hitch hangs down too low. If only Jayco mounted the tow ball receiver on top of the drawer bar I could shorten the HR hitch.
http://www.expandasdownunder.com/showthread.php/52-Tyre-Loads

I'll take a photo of the mod tomorrow and post it up.
 

Moto Moto

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G'day Moto. I have had the local Jayco dealer at Tweed Heads fit the 50mm block (actually 2 x 25mm blocks) to my tow ball receiver which means my draw bar has dropped by that amount and raised the rear of the van which was my aim. But as I showed in aprevious post, my Hayman Reese hitch hangs down too low. If only Jayco mounted the tow ball receiver on top of the drawer bar I could shorten the HR hitch.
http://www.expandasdownunder.com/showthread.php/52-Tyre-Loads

I'll take a photo of the mod tomorrow and post it up.

Thanks Chartrock that would be great. Trying to avoid having use the big bulky hitches on the Patrol.
 

chartrock

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Here are a couple of pix of the draw bar 50mm lift.

DSCN3827.JPG DSCN4363.JPG DSCN4362.JPG DSCN4360.JPG

Before the lift
 

cruza driver

Hercules
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Today i ordered a spacer/packer that raises the tow hitch on the van by 50mm. Jayco Canberra sell these for about $150. I have asked them to fit one to my Expanda ready for delivery time.

I plan on doing a 50mm lift on my Patrol soon so thought i would get this done now considering i am getting an "overslung outback". I'm worried to hitch height will be too low standard and i don't really want to run a drop hitch thingy.........................
It will be interesting to see how it comes up, I run a lower drop hitch and it is lower than I'd like but so far it hasn't posed a problem. My Cruiser is lifted around 2 1/2'' and the drop tongue is 75mm.
 

chartrock

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Theoretically the hitch should only go up the height of the axle........shouldn't it? :confused:

Cruza, the bottom of the axle is on the top of the springs when overslung, you move it to the underslung position and the top of the axle is under the bottom of the springs, so the chassis has been raised the height of the springs plus the height of the axle.

I hope that makes sense. :(
 

Moto Moto

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Gotta love this forum!

Hey Cruza, i know you run a treg/trig? coupling, I have been told the spacers should work with that and the Hyland (that i have ordered) as well:cool:
 

cruza driver

Hercules
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Cruza, the bottom of the axle is on the top of the springs when overslung, you move it to the underslung position and the top of the axle is under the bottom of the springs, so the chassis has been raised the height of the springs plus the height of the axle. I reckon the blocks look like an ideal solution to the low hitch height

I hope that makes sense. :(
yep it all makes sense as with a underslung axle the hitch height is raised, compared to an overslung axle.
 

Peter D

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Jun 12, 2011
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Brisbane
I'm confused (and currently have my wine goggles on, so beware!).

If you undersling the axle, won't the problem be that your hitch will then be around 4 inches higher than it used to be, and likely be too high for the height of the ball on your tow vehicle? So won't the objective then be to lower the height of your hitch, not raise it?

(The family has recently gotten a 17-56 non-OB, and after scraping a wide new gouge in the seller's driveway with the underslung spare tyre carrier as we left (the difference between his Navara suspension and our Pajero suspension - his only left light gouges in his driveway), the idea of raising the suspension gained new relevance with me. And ours has a top-mounted hitch, and I haven't seen any aftermarket way to lower the hitch height on a top mounted hitch.

First post. Hi all.)