Suspension Off Set Axle Banter thread

mikerezny

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Sep 11, 2016
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#2
you cannot just rotate your axle , your brakes won't work and alignment will be out, Don't Do It.
Hi @Drover,
thanks for the very detailed step-by-step guide.

I have a question:
Would it be possible to both rotate the axle AND swap it around (Left to Right)? If I understand this correctly, brakes would then be in the correct position.

cheers
Mike
 

Drover

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#3
No the set up would still be wrong. These brakes have a right, left, front, back and top, bottom configuration including the backing plate and gravity plays a part in them working as well I believe. Swapping the spacer from bottom of axle to the top is an easy fix, a spot weld on it is more to keep it in position when fitting everything together than being an integral part of the units integrity, the U bolts are whats holding everything together so they require to be done up properly and tension checked every so often, you could infact gaffa tape the spacers in position and drop the spring onto it and all would be good.

Hope that explains it okay, I know it doesn't work in theory and in practical, I tried some short cuts that weren't once upon a time.
 
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Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
#4
I must also point out before doing this, on a level pad measure the height of your tugs towball from the ground then measure the height of your vans tow hitch when level, add 90 -100mm to it because your tugs tow ball will need to be 25mm higher than the vans, so just see if it's possible to get this extra ball height on your tug first.......tugs ball as a rule of thumb should be around 25mm higher than the van to give a reasonable chance of being level when hooked up.......extra height of van is determined by width of spring pack and width of axle...................

Well done @Drover !! Very explicit instructions and I love the "SAFETY' bit. One cannot be too careful when fully under several hundred kilo of suspended weight. And yes, altering the axle does give more clearance to the body, but the straight axle is STILL the lowest point. And a lot of people forget underslinging the axle will affect the height connection to the tow/hitch point. @mikerezny , as you have the same van as me, I will send you some piccies of what it looks like from underneath. getting ready to go bush on Monday, so will be checking underneath on Saturday.
 

Boots in Action

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Mar 13, 2017
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#5
Hi @Drover,
thanks for the very detailed step-by-step guide.

I have a question:
Would it be possible to both rotate the axle AND swap it around (Left to Right)? If I understand this correctly, brakes would then be in the correct position.

cheers
Mike
Hi @mikerezny , @Drover "may " not be quite correct in what he says as applies to our (mine at least) Penguin. From the attached photos, it seems that the beam axle has an offset section welded on to it, and this has a square plate welded onto the end of it. This square plate has 4 holes in it, through which 4 studs from the wheel backing plate protrude. This enables the square plate on end of axle to be attached to wheel backing plate and stub axle with 4 bolts. See photos.

From looking at my van, I can see that the whole beam axle has been able to be rotated 180 degrees without any problems. The protective cover for the wiring now faces the rear of van (instead of on front of axle) and wiring has been rerouted to be behind the beam axle. No changes made to brakes or parking brake position as they are on the wheel backing plate, not the axle!! Also note that there is a small plate between the axle and the leaf springs which are now ABOVE the axle instead of being BELOW. The springs and the "U' bolts now face upwards, not tied below the springs and axle.
Height.JPG
Pin.JPG
Pin.JPG
Plate.JPG
Setup2.JPG
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This small plate is welded onto the beam axle and has a locating pin attached to it. This steel pin positively locates the leaf springs ( see photo of top of pin through springs) which are held fore and aft by shackles.

This van has definitely had the axle rotated 180 degrees and the springs placed above axle to provide greater body clearance. From the pictures, it looks like the offset on the axle has now reduced axle clearance by the thickness of the offset, but body has been raised by the same offset plus the different positioning of the springs. Just as well I have pictures of this, otherwise nobody would understand it at all!!! Other photos show that the body of van now has at least 540mm clearance at step point , which has necessitated us using a small foot stool to help getting in and out. Big bottom step!!! Generally speaking, there is now a lot more BODY clearance than before, but height of beam axle may be slightly lower. Not good for going over humped tracks, but great for entry and departure over deep dips/gutters.

I now wait for @Drover's comments on this setup. Probably different on Expandas and never as good as OB. But you cannot have everything!! I hope this helps all members understand the term "under-slinging the axle/s" and its benefits for greater body clearance. Cheers
 

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Drover

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#6
If you read the OP you will see its stated that it applies to STRAIGHT axles.........you don't have a straight axle, I think if you pull the drums off you might find a few other things changed. And since this thread is for underslinging straight axles I'm not getting into some banter about bent ones.
 

Drover

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#7
Can't help myself, the locating pin you mention is actually the centre bolt of the spring, found on all spring sets, the small plate is called a spacer, required to allow room for centre bolt, the big plate the U bolts goes thru is called a fish plate.....and with an off set axle they are designed for the stub to be about the height of the spring so the gain from the set up being under or overslung isn't great mostly...........the backing plate holes are offset so brake fits one way unless you drill a new set of holes......from your pics it seems you have a left hand brake set on the left hand side so nothing changed, might be a factory set up.........not mistaken at all, thank you.
 
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Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
#8
If you read the OP you will see its stated that it applies to STRAIGHT axles.........you don't have a straight axle, I think if you pull the drums off you might find a few other things changed. And since this thread is for underslinging straight axles I'm not getting into some banter about bent ones.
Steady on @Drover , this area is way outside my area of expertise. Only intended to show how mine is set up and that it was very different to the one you were explaining about a "straight axle". I was not aware that the axle on my Penguin was considered a "bent axle", hence my mistake there. Each person has a field of specialised expertise (mine is electrical/solar systems) and I thought that you would straighten up my thoughts on this. You took the bait well and truly and I am thankful for the information you have provided in correcting me. What I was really looking for was your thoughts on this sort of setup. I guess you have done that now. Please read the first sentence in my post again which refers to "as applies to our (mine at least) Penguin" and "may not be correct". No disrespect ever intended.
 

Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
#9
Can't help myself, the locating pin you mention is actually the centre bolt of the spring, found on all spring sets, the small plate is called a spacer, required to allow room for centre bolt, the big plate the U bolts goes thru is called a fish plate.....and with an off set axle they are designed for the stub to be about the height of the spring so the gain from the set up being under or overslung isn't great mostly...........the backing plate holes are offset so brake fits one way unless you drill a new set of holes......from your pics it seems you have a left hand brake set on the left hand side so nothing changed, might be a factory set up.........not mistaken at all, thank you.
Hi again @Drover , thanks for the information on the proper names and fitting of plates, spacer and centring pin for springs. I did not know what to call them and tried to explain them "as I saw it". Fortunately, the photos allowed you to at least see what I was trying to talk about. Not known if it was a "factory setup", as when I purchased the van nearly 3 years ago, I thought that under-slinging the axle would be a good idea for the areas I was going to explore. Arranged with a well known caravan repairer at Brendale to do the modification I requested, and that is how it happened. Needless to say, I have found it very satisfactory and several other "smaller" van owners have asked why my van sits higher than theirs. Others have wanted to purchase an OB version but were unable to tow the extra weight or were cash short. They thought that what I had done was a possible alternative that might enable them to at least reach some of their proposed destinations without suffering body damage on creek crossings etc.

Now is the time for me to sit down and have a good think of what you have explained, so that I have a better idea of how this modification may affect other members on this forum. "May not be correct" in relation to "bent axled Penguin" is NOT SAYING YOU ARE WRONG on straight axled other vans.
 

Drover

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#10
The change in height by moving an off set axle would only be in the 10 - 15mm range, they were made to keep the vehicle low, use smaller wheels so the axle was out of the way, with axle underneath the spring a 50mm axle with a 50mm stub welded on one edge means the axle stub is in the same line as the spring pack which is possibly 50mm, there fore the thing making the height movement is the 10mm spacer block, if I wanted to increase the body height I would chuck the off set axle and fit a straight axle............Changing tyres/wheels would change the heights also.......................of course the bigger the difference in spring pack/axle thickness does vary the height gain or loss.

If you pop a brake drum off and look at the workings of the brake you will see why they only work on one side, rotation, gravity and angle of the dangles dictate it, interestingly the electric brakes won't work in reverse, well not real well anyway.

I dare say your caravan fella rolled the axle, removed and swapped the backing plates so the drums would be in the correct position, if it all works for you and your happy then it's the perfect set up.........a bigger spacer block would increase your height if needed...

I rise to "Bait" easily at times, also you can see the reason why I stated applies to straight axles, I suppose I should also note that these Off Set axles are also called Overlay Axles......maybe a thread on Off Set axles would be better.
 

Boots in Action

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Mar 13, 2017
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Ferny Grove, Queensland
#11
The change in height by moving an off set axle would only be in the 10 - 15mm range, they were made to keep the vehicle low, use smaller wheels so the axle was out of the way, with axle underneath the spring a 50mm axle with a 50mm stub welded on one edge means the axle stub is in the same line as the spring pack which is possibly 50mm, there fore the thing making the height movement is the 10mm spacer block, if I wanted to increase the body height I would chuck the off set axle and fit a straight axle............Changing tyres/wheels would change the heights also.......................of course the bigger the difference in spring pack/axle thickness does vary the height gain or loss.

If you pop a brake drum off and look at the workings of the brake you will see why they only work on one side, rotation, gravity and angle of the dangles dictate it, interestingly the electric brakes won't work in reverse, well not real well anyway.

I dare say your caravan fella rolled the axle, removed and swapped the backing plates so the drums would be in the correct position, if it all works for you and your happy then it's the perfect set up.........a bigger spacer block would increase your height if needed...

I rise to "Bait" easily at times, also you can see the reason why I stated applies to straight axles, I suppose I should also note that these Off Set axles are also called Overlay Axles......maybe a thread on Off Set axles would be better.
Thanks for the reply @Drover , I now have a greater understanding of what was involved by caravan mech at Brendale. I guess swapping the backing plates was something I was unaware of as it all looked so easily done from underneath and there was no evidence that anything had been done to the backing plate/nuts. When I had the van serviced recently by a mobile caravan servicing guy, I did notice that the position of the magnetic coils, so that when braking is applied, forward movement of the wheel (brake drum actually) pulled the primary shoe away from the anchor pin and forced the secondary shoe rearwards against the common anchor, thus jamming it against the brake drum. I am aware of how drum brakes work on a car having had lots of experience in that area. Fully understand now why just rotating backing plate would NOT work. Still a bit mystified as to how I gained so much extra height as never had to use an extra foot stool to get on/off the bottom step of van steps previously, but also noted how a bigger spacer block would increase height if needed.
I for one would be interested in your thread on Off Set or Overlay Axles and how Underslinging may change the dynamics in towing a van.
 

mikerezny

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Sep 11, 2016
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#14
Hi @Boots in Action,
many thanks for taking the time and effort to take the photos and give such a detailed explanation. Very much appreciated.

I have taken and attached a couple of pictures of the axle on our standard touring Penguin. Comparing your pictures and these we should be able to determine how your Penguin was raised and what the effect would have been.

Correct me if I am wrong, but on comparison, it would seem that your complete axle assembly was simply moved from being above the springs to below the springs. Considering that the protection stripfor the electric brake cable is still in the original position, there has been no other rotation etc.

So, the process seems to have been:
undo the ubolts, electric cables, and handbrake cables,
undo the spring shackle and remove the complete axle assembly,
grind off the positioning plate from the bottom of the axle beam and re weld it the top of the axle beam, and
reassemble

If that is indeed the case, you should be able to see some marks on the bottom of your axle showing where the positioning plate was ground off.

If this is all correct, the total lift you achieved should have been the width of the spring assembly plus two times the thickness of the backing plate.

The only other slight difference is that the welds for your backing plate are North-South whereas on mine they are East-West.
However, my original axle assembly was subject to an ALKO recall and was replaced by the dealer prior to delivery. I remember them saying that they
had to grind the positioning plates off the original axle and re-weld them onto the new replacement assembly. So, Penguins coming out of the factory may be welded differently.

What do you think?

My how times change. When I was 17, I had a Holden FJ, then an FC. Big deal then was to replace the 15" wheels with wider 13" ones, put in lowering blocks on the rear and cut a turn or so off the front springs. Then other tricks to the rear to reduce axle tramp and swaying. Oops, I am off-topic again!

cheers
Mike


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Drover

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#15
That's interesting all the off sets I have come across the stub is 180 deg to yours @mikerezny and thats the biggest weld on a spacer too boot also explains the lift on boots' van.......it certainly would give you around 50mm lift......... The brake line wouldn't get hit by the chassis if hitting a monster hole would it ?

It's amazing they have so many variations of doing things.
 
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Drover

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#17
It probably won't just the angle of the pic, I think I might start a collection of Axle set up pics, the diversity is quite wide for individual basic sets, can be quite interesting to see the variations though i don't think rolling an off set a full 180 to bottom of axle would be a good idea with the stub hanging down, just looks like the stress on the components would be way overboard.
If you set yourrs up like @Boots in Action has his I wouldn't bother removing the spacer just place a new one in the same position on the other side of axle, as I said before it positions the spring while fitting but if things get loose the movement breaks the centre bolt anyway, you know as you start to crab down the road......

Oh and don't worry about things hitting underneath, Murphys law decrees it will hit the wheel, much more effect than banging the axle.......really empty the cupboards then.

Redid this thread to reflect the direction things have gone and made a new straight axle slinging thread., so you can rabbit on about off sets to your hearts content.............Drover aims to please...
 

bigcol

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Nov 22, 2012
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#18
I have only ever seen "off set" axles like these on Compressor trailers (and bobcat trailers, and Genset trailers etc) I thought they only used them on industrial set ups - for long life of abuse type thing
 
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