Jacking points

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21 Apr 2018 09:46 #1 by tcgreen
tcgreen created the topic: Jacking points
Hi,
I have been looking at what jacking points to use with a hydraulic jack. The oka manual indicates the underside of the round axle tube. Has anyone had any problems with the jack slipping off the round tube?
Also, the jack point for the front drivers side appears to be the bottom of the "C" at the end of the axle tube. Is this correct?
I am still getting to know my new oka. Appreciate the advice.
Cheers
Tony

Tony & Chris
Oka 334 motorhome.
Cummins 6bt, 4L80e auto, Nissan transfer.

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21 Apr 2018 10:42 - 21 Apr 2018 11:12 #2 by dandjcr
dandjcr replied the topic: Jacking points
Tony, yes, bottle jacks with a small round head can easily slip off a round surface (or a flat surface at an angle). Don't use the C section on the front axle, it's not flat and can be covered in oil.

I would suggest you acquire a saddle, something like this:



It's a US made item from Safejacks. They are available from ProQuip in Oz, but you could easily weld up something similar. It's strange that bottle jacks are ten-a-penny but they all have just a small round head. I couldn't find any similar saddles from the usual local suspects.

I jack under the spring mount when possible, on the axle tube between the U bolts using a jack with a saddle, and use axle stands for additional safety. Very rarely can you jack under the chassis, it's too far from the ground.

You also need a heavy duty jack 6-10 tonnes capacity preferably, Normal car jacks (1-2 tonnes) are not adequate for a 5+ tonne vehicle.

If you have or plan to get a Hi-Lift jack, which can be very useful for getting out of a tricky situation, there are jack points on the front and rear bullbars, if fitted, but I found them awkward to use effectively, and it's difficult to raise a wheel off the ground using them. So I added hi-lift jack points to sides of the bulbars, see here. .

You can also lift a wheel using a hub adaptor which fits over the hub and can be raised using a bottle or hi-lift jack (handy for debogging or when you can't get a jack under the axle), but then you can't remove the wheel without using an axle stand and lowering the jack.

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
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Last Edit: 21 Apr 2018 11:12 by dandjcr.

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21 Apr 2018 12:20 #3 by Tony Lee
Tony Lee replied the topic: Jacking points
If you intend using the jacking points on the front bull bar, you will actually need two high lift jacks if you choose the wrong one to use.. First one lifts OK but when you try to change the mechanism over to lower mode, you might find it hard up against the bull bar so then you need the other jack to take the weight off the firt jack so you can slip it out. Very clever design.

I used David's suggestion which is much smarter - except that neat and tidy is too much trouble so instead of a neat rectangular hole, mine is just cut out with a hole saw.

Tony

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21 Apr 2018 18:52 #4 by Holmz
Holmz replied the topic: Jacking points

Tony Lee wrote: ?..
I used David's suggestion which is much smarter ...


This?
www.oka4wd.com/images/pdfs/techdocs/AddC...%20Jack%20Points.pdf

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21 Apr 2018 20:13 - 21 Apr 2018 20:18 #5 by Tony Lee
Tony Lee replied the topic: Jacking points
Just on the front of course since I have no bumper bar on the back.

I've tried the hole I cut and seems to be no deformation as it takes the weight although the round hole is smaller than David's cutout.

I have tried lifting on my living quarters sub frame at the back and seems to be OK.

One big problem is the height of the OKA and although my jack is extra height and supposedly a heavy frame, I don't think it would take much of an 'upset' when the load is on to end up with a banana'd jack

I would suggest NOT to use the original lifting point on the passenger side front bar as you WILL end up with a vehicle in the air and no way of lowering the jack.

Tony
Last Edit: 21 Apr 2018 20:18 by Tony Lee.

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22 Apr 2018 10:25 #6 by tcgreen
tcgreen replied the topic: Jacking points
Thanks guys for all the helpful info. I feel I am on the right track now.
Cheers
Tony

Tony & Chris
Oka 334 motorhome.
Cummins 6bt, 4L80e auto, Nissan transfer.

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22 Apr 2018 17:06 - 22 Apr 2018 17:21 #7 by OKA in Africa
OKA in Africa replied the topic: Jacking points
My thoughts on the topic:
A standard hydraulic jack works well for me in most cases (changing the tyre), which I use to push up the round axle. Until now it never slipped but I always use an additional vehicle jack under the axle as a safety precaution in case it slips. When I had a flat I was always at reasonably flat terrain or able to roll a couple of meters to a flat location.

However, the hydraulic option does most likely not work anymore if you are bogged down. I do try to avoid this under all circumstances. Apart from a winch and tow strap, I have a long high lift jack and of course my most efficient recovery device - my spade.
Luckily I never needed to use the high lift jack until now but would use it as displayed in the pictures below.
But ... using it this way is highly dangerous and could result in serious injury. Furthermore, I did realize that the weight of the OKA is actually to high for the use of a jack. I do weight around 90kg and do barely manage to push the high lift jack handle down despite loading it with my full body weight.

The "nose" of the high lift jack does fit perfectly into the groove of the rim, but (again) this is dangerous and could slip off easily. It is obviously a big advantage if you can attach the jack to the wheel since you do not have to lift the vehicle out of its springs and it is still a project of mine to build a simple "axle hub/high lift jack adapter".

The adaptor would consist of a solid piece of iron pipe with a piece of rectangular bar welded to it. The pipe would fit over the axle hubs and the bar would fit into the jack. The concept of the adaptor is shown via the first of the helpful links to this topic:

dandjr.wordpress.com/2010/12/24/recovery-and-maintenance-gear/
www.oka4wd.com/forum/manuals-tools-faste...-jack-hydraulic#8958
www.oka4wd.com/forum/oka-maintenance/1078-hi-lift-jack#4878


Thank you and best regards

OKA #327 in Africa
www.oka4wd.com/forum/members-vehicles-pu...47-oka-327-in-africa
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Last Edit: 22 Apr 2018 17:21 by OKA in Africa.
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22 Apr 2018 22:51 - 25 Apr 2018 08:41 #8 by dandjcr
dandjcr replied the topic: Jacking points

OKA in Africa wrote: it is still a project of mine to build a simple "axle hub/high lift jack adapter".

The adaptor would consist of a solid piece of iron pipe with a piece of rectangular bar welded to it. The pipe would fit over the axle hubs and the bar would fit into the jack. The concept of the adaptor is shown via the first of the helpful links to this topic:

dandjr.wordpress.com/2010/12/24/recovery-and-maintenance-gear/


OIA, here's a link to a better version of my Recovery Gear article. Damn you Photobucket!

I had one of the red hub adaptors you mentioned but it failed at the worst moment during a debogging exercise, couldn't support the weight and buckled. Fortunately there was enough meat showing so my screw jack still worked. But I also needed my hi lift jack as well.





After that I got a much stronger hub lift adaptor (made by a mate of mine, thanks Dave and David) along the lines you proposed. The orange packing section allows it to be used on the front hubs as well as the rear.



The square receiver fits the Hi Lift jack (in pieces being overhauled) and also a standard 50mm tow hitch so I can also use normal jacks.





I agree a high lift jack does require a LOT of effort to operate using the Oka jacking points but is a bit easier with my side jacking points. And you do need a solid base for soft ground.

The shear pin (below the handle at the bottom of the short pitman link) should break if the load (from the handle!!) gets too high. The jack then stays where it is and won't fall down so it's a good idea to carry a spare overhaul kit. Otherwise I don't know how you'd get the Oka off the jack. You could probably use any bolt/tent peg to temporarily replace the shear pin if necessary (not recommended), but the official shear pin has a specific breaking point to protect the jack from overload. I've never reached that point.

The biggest danger I've encountered with a high lift jack, is not when raising a load but when lowering it. As the top climbing pin releases and the lower one engages, the vehicle weight causes the handle to shoot upwards surprisingly fast if not properly under control which can catch you under the chin, or worse (it's happened to me). This more likely when using the jack at a low level, like with the hub lifter. Never lean over the handle, always pull down from the side or behind the handle.

Here's the warning statement from the Hi Lift jack instructions:



The other danger is from the spouse, who I got to hold the handle at exactly the right point while I fitted a replacement suspension pin, but then forgot to tell her she could let go. She was displeased.

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Last Edit: 25 Apr 2018 08:41 by dandjcr.
The following user(s) said Thank You: OKA in Africa

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23 Apr 2018 04:58 #9 by Holmz
Holmz replied the topic: Jacking points

dandjcr wrote:
...
After that I got a much stronger hub lift adaptor (made by a mate of mine, thanks Dave and David) along the lines you proposed. The orange packing section allows it to be used on the front hubs as well as the rear.
...


Do you have dimensions? ID or OD of tube and thickness?

The small 'screw jack' looks handy for tight spots. Is there a name for them?

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23 Apr 2018 06:35 #10 by outyonda
outyonda replied the topic: Jacking points
doo the maths

hi lift jack 900 kg
OKA tyre load capasity 1500 kg per corner + suction + beer + wine !!

leave hi lift jack on scrap heap ware they belong

OKAs 091, 093, 094, 113, 346x6 & 405

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23 Apr 2018 07:05 - 24 Apr 2018 19:06 #11 by dandjcr
dandjcr replied the topic: Jacking points
Brett I think you're being a bit too harsh on Hi Lift jacks.

Yes they can be dangerous in the wrong hands but so can any other lifting/pulling/pushing device. Eg, they can be used as a rudimentary winch or pusher, but when using it that way your standing in exactly the wrong place if something fails. Safejacks sell a range of safety devices to make jacking safer, some of which could be emulated at home.

In the several times we've got stuck, our Hi Lift jack has been the primary (but not only) tool to help us out. And to lift the Oka a metre or so in the workshop to place it on chassis stands to remove springs or axles, I don't know any other commonly available method, other than a Bobcat, forklift, front end loader or similar. Using a winch to lift is possible but sounds even more risky.



I certainly wouldn't rely solely on a Hi Lift jack for remote travel but I wouldn't be without it either.

Holmz, I'll check the hub adaptor dimensions for you.

Our screw jack has an interesting history. Janet's father found it on the side of the road in the UK about 50 years ago, some truckie had left it behind.

It's a heavy, very solidly built, 3 tonne, dual acting screw jack made in Birmingham in 1929 in the days when things were built to last. When we left the UK in 1974, the jack came with us on our overland trip and has been our main lifting device ever since.

Hydraulic jacks may be lighter and a bit easier to use (I have a couple of bottle jacks and a trolley jack), but I would trust my screw jack a lot more than a hydraulic jack to stay up when I'm under the Oka placing axle stands, and it has a huge 10 inch lifting range.

It also works horizontally (or upside down), as when pushing an axle with a broken spring back into alignment.


David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
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Last Edit: 24 Apr 2018 19:06 by dandjcr.

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23 Apr 2018 08:03 #12 by mort
mort replied the topic: Jacking points
Hi Brett,
I am not sure which Hi lift jack you are talking about, I have one rated at 3175 kg and one at 3850 kg. I guess if I had located in the exact spot with one in front and rear I could lift the OKA off the ground and I do recall seeing one in Holmz OKA rated at 3200 kg so maybe you dont have a genuine one.
I have a spare if you want one.
Martyn

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23 Apr 2018 15:34 #13 by dandjcr
dandjcr replied the topic: Jacking points

Holmz wrote: Do you have dimensions? ID or OD of tube and thickness?


Holmz, the rear hub is nominally 120mm diameter and the front is 105mm.

The hub lifter tube has ID of 123mm (probably a 5 inch stock size) and it's all 5mm thick. The packing piece was chosen to fit the front hub.

The square tube is 55mm square inside.



The length is 120mm and you don't want it too deep, you need the jack to lift as close to the wheel as possible. A purist would probably cut slots in the rear to fit around the wheel nuts but my old red lifter did that and needed the wheel turned so the lifter was more or less vertical.

The strength is in the quality of the steel tubing and the welding, and if I was making another one I'd fit front fillets like at the rear. Cast iron would not be a good idea...

Note the notch inside the top of the tube for the strengthening rib below the Hi-Lift jack nose to fit, and the slot at the back of the top for the lip of the jack. The hole in the side is for the tow bar pin and can also be used to secure the Hi-Lift jack (probably unnecessary).

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
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23 Apr 2018 16:00 #14 by OKA in Africa
OKA in Africa replied the topic: Jacking points
Dear David,
very interesting design! Do you have some more dimensions on the adaptor, I am thinking of getting one made for myself?
Did you use the adaptor during an actual debogging situation, how did it perform? Do you have some pictures of the jack attached to the adaptor?
I understand your point of having the jack as close to the wheel as possible to reduce leverage/momentum forces. However, I would assume that having the adaptor a bit loger to "extend" the hub would make it easier to get debogged, i.e. the high lift jack stand would not be so close to the wheel were I would have to dig later and insert stone/wood material to support the wheel/traction later?

Thank you and best regards

OKA #327 in Africa
www.oka4wd.com/forum/members-vehicles-pu...47-oka-327-in-africa

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24 Apr 2018 05:54 - 24 Apr 2018 06:15 #15 by dandjcr
dandjcr replied the topic: Jacking points

OKA in Africa wrote: Dear David,
very interesting design! Do you have some more dimensions on the adaptor, I am thinking of getting one made for myself?
Did you use the adaptor during an actual debogging situation, how did it perform? Do you have some pictures of the jack attached to the adaptor?


OIA, the original design was done by Dave/David in Perth after my red lifter collapsed, but I added the suggestion for using a tow hitch/normal jack as an alternative lifting method to a hi lift jack. In a workshop a trolley jack with enough reach could be used for a quick wheel raising without having to scrabble under the Oka.

There's no technical reason why the lifter couldn't be longer (as it effectively is using the tow hitch method) but moving the lift point outwards would put more stress on the lower edge of the hub unless it was a tight fit, and that might mean fitting and removal would become more difficult (I expect the round tube to be pulled a bit out of shape/oval during a real life operation).

I haven't tried it yet, but I can't see why a high lift jack couldn't be used sideways under the tow hitch extension, although it would be less stable.

Also note that the front hubs are smaller and with thinner walls than the rear (I'm told, haven't checked that) and therefore more susceptible to stresses. Being bogged is bad enough but breaking a front hub would be worse.

But no I haven't had to use it in an actual bogging situation yet but I have tested it in my shed and it worked fine. In our real bogging experience I used the original hub lifter/screw jack and hi lift jack both at the same time to alternately lift the Oka body and wheel, (which is why I needed the lifter to be useable 2 ways). That spread the load/reduced the stresses quite well on jacks and operators, although soft ground was a problem (but I guess you never get bogged on firm ground).

No other photos yet, but once I get my hi lift jack back together I can take some. I put the basic lifter dimensions in the above post for Holmz, what additional dimensions do you need? The cutouts/slots will depend on the jack model and you could probably think of some more adornments, such as a bracket to attach the lifter to a wheel stud(s) for stability and a flat base on the bottom. Then you could jack directly under the lifter for more lift, although top lifting (pulling up) is safer than pushing.

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Last Edit: 24 Apr 2018 06:15 by dandjcr.

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24 Apr 2018 15:56 #16 by Holmz
Holmz replied the topic: Jacking points

dandjcr wrote: ...

No other photos yet, but once I get my hi lift jack back together I can take some. I put the basic lifter dimensions in the above post for Holmz, what additional dimensions do you need?
....


I though afterwards, I could have measured my hubs... ;(
Going to the metal shop this weekend, and busting out the welder at some point after that.

Should I bring it to a stick man, or just TIG it?

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24 Apr 2018 16:32 - 24 Apr 2018 19:09 #17 by dandjcr
dandjcr replied the topic: Jacking points
Quote: Should I bring it to a stick man, or just TIG it?

Don't know Holmz, I'm not a metallurgist and only an amateur welder.

But the whole weight of one corner of the Oka (1-2 tonnes) will be hanging on the welds so they need to be strong. Mine was designed and built by a professional welder serving the mining industry, and who knew exactly what it was for.

The lifter could be reinforced with a strap welded around the whole thing but with professional welding that shouldn't be needed.

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Last Edit: 24 Apr 2018 19:09 by dandjcr.

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24 Apr 2018 21:09 #18 by Holmz
Holmz replied the topic: Jacking points
TIG should be good, and I found a few filler rods that are recommended.
So I'll see if those tube diameters are available at the shop and then have a go.

Also steel I do OK on as well as Aluminium using TIG, so I should be OK with it.

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25 Apr 2018 12:34 #19 by OKA in Africa
OKA in Africa replied the topic: Jacking points
With the design displayed I would not worry about stressing the rear hubs to much. When I changed by broken rear side/half shaft I saw that the hub drum itself is pretty solid, it has to carry all the turning load from the shaft to the wheel. I do not expect the rear hub to deform under load when lifting with the adaptor.
However, the front wheel hub is designed differently and I want to open the hub and check the thickness. There is another concern I have about the front wheel hub apart from the thinner hub wall. I think that hub lock assembly mounted at the end of the front wheel hub would brake or at least deform when using the adaptor. My lock assembly is slightly misaligned with the hub itself. Using the hub adaptor in the designed way would probably shear off the lock assembly under load.
Maybe this could be solved with an adaptor metal tube only that long that it will only cover the hub and not the hub lock assembly.
Maybe I am over cautious here, any thoughts on that?

Thank you and best regards

OKA #327 in Africa
www.oka4wd.com/forum/members-vehicles-pu...47-oka-327-in-africa

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25 Apr 2018 12:57 #20 by mort
mort replied the topic: Jacking points
Hi OIA,
I would agree with the rear it is alot stronger and add the axel end with the bolts it would be almost impossible to damage and yes the front could be an issue especially the lock but how strong the rest is I have not considered but now that I will make one I need to satisfy myself.
Martyn

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