Bottle Jack Cradle?

[Ol’ Timey Manual SWB Guy]

I find it weird that a major USA bottle jack manufacturer (US Jack) and a major USA axle-cradle manufacturer (Safe Jack) don’t seem like they’ve coordinated to qualify a domestically-sourced solution at the scale of a JL axle. Sorta frustrating, tbh. I’m surprised the Army hasn’t required it.

According to this .pdf (Column F), the shaft diameter on a hi-lift 5-ton jack is 1.375” and the down-tube of a Safe Jack cradle is only 1.25” ID.

I mean… maybe they fit together??? Maybe the lifting pad (button) is slightly smaller than Column F.

But you think these two firms would work together and qualify a solution.

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[Ol’ Timey Manual SWB Guy]

Related: this custom 3D printed bottle jack screw collar is genius. It purports to keep the threaded shaft centered under the load, thus keeping the lifting pad square against the underside of the collar assembly. No rattling or shifting. Smart.

But I’m not buying $500 worth of parts just to see if they happen to work together correctly, rather than being 1/16” off on either side.

Has anybody tested these bits all together?

 

[TNriver]

Related: this custom 3D printed bottle jack screw collar is genius. It purports to keep the threaded shaft centered under the load, thus keeping the lifting pad square against the underside of the collar assembly. No rattling or shifting. Smart.

But I’m not buying $500 worth of parts just to see if they happen to work together correctly, rather than being 1/16” off on either side.

Has anybody tested these bits all together?

The Power Mountain Tallboy Off-Road Bottle Jack comes with a steel adapter collar.

 

[azwjowner]

So 37s, half that is 18.5, minus 2 inches for axle.you need a jack that collapses to 16 inches, and then goes up to 22.

Or you jack up the axle a bit, put a small 4x4 block under the flat tire, let off the bottle jack and reset. Then it’s plenty of travel.

 

[CloakedWillys]

I ended up using a bottle jack that I had aro9und and welding this to the top. Ends up fitting in the back tray.

https://www.swagoffroad.com/products/swag-bottle-jack-axle-cradle?_pos=5&_sid=618f96400&_ss=r

 

[Dadgummit]

I looked into the bottle jacks as a more compact solution to Hilift Jacks. What I finally found is it really does not matter what extensions you buy or blocks of wood you use you need to make sure of one thing. You need to look at the amount the jack extends, which is usually 5-6 inches, and compare it to your side wall of your tire. The jack's stroke must be longer than the sidewall is high and you cannot add in extensions nor can you add in the screw thing at the top of the jack. .

If you get a flat tire and put the bottle jack under the axle tube and the jack has a 6 inch stroke you are only able to jack it up 6 inches and if the tire has a 7 inch sidewall you will be able to get the old/ flat tire off of the jeep but you will not be able to get the new tire onto the hub because the Jeep will still be too low. Stock rubicon tires have over 7.5 inches of sidewall and there are very few bottle jacks have a stroke that long.

If you have a sport model with the car tires it may work but not if you have larger tires not so much. All the extension in the world will not help you with this unless you play a musical chair game with jacking it up, using a jack stand to hold the jeep in the new position, put an extension on the jack and jack it up again.


As an alternative this one looks pretty interesting though I have not tried it yet: https://www.amazon.com/gp/product/B0D63QN5JC/ref=ox_sc_saved_title_5?smid=A29MUERPS76DU9&psc=1

 

[Jay_NM]

This is really intriguing. A bottle jack and jackstand combination.

https://www.amazon.com/gp/aw/d/B003ULZGFU/ref=cart_bc_item_title_1?smid=ATVPDKIKX0DER&psc=1

 

[THAW]

If you get a flat tire and put the bottle jack under the axle tube and the jack has a 6 inch stroke you are only able to jack it up 6 inches and if the tire has a 7 inch sidewall you will be able to get the old/ flat tire off of the jeep but you will not be able to get the new tire onto the hub because the Jeep will still be too low. Stock rubicon tires have over 7.5 inches of sidewall and there are very few bottle jacks have a stroke that long.

While bottle jack ram stroke can be limiting, the above statements are geometrically incorrect. The entire axle doesn't drop by the amount of the tire sidewall (unless both tires flat). In the case of a single flat, the farther along the axle away from the flat tire, the smaller the drop (i.e. the undamaged-tire end of the axle effectively doesn't drop at all). So, a bottle jack placed in the center of an axle tube doesn't have to lift the axle by the amount of the tire sidewall to level the axle (because the axle moves in an arc whose center is roughly at the hub of the intact tire, and the arc radius at the flat tire is longer than the radius at the jack).

The quoted post is actually the second misleading one on the subject; the "math" of the first misleading post implied an axle drops all the way to the ground on the flat-tire side, as if there were no wheel/hub-assembly.

 

[Dadgummit]

Your use of geometry though it is correct in a perfect world you are "misleading" the OP in that you forgot to mention that your Geometry hack to get an extra inch of travel is far less stable/safe. The further toward the pumpkin you place the jack the heavier the load the jack is carrying because you are lifting both sides of the jeep instead of just the side with the flat. I am not worried about the jack its self because they have several tons of capacity however when you are essentially lifting most of the entire rear of the jeep with a bottle jack that only has a few inches square of base, you have a less stable set up than if your were further out toward the tire. People have lost limbs from unstable jack set ups, If this works for you that is Awesome and I wish you the best, however I like my limbs, I have had them since I was a kid

 

[Terrymo]

I’m confused where the idea that a bottle jack can only lift 5-6 inches comes from. The taller the jack body, the more travel the ram has generally, Then there are double ram jacks. I would let all the air out of the tire and see how much room there is under the lift point, and buy a jack and cradle based on this. Or maybe I’m just lost in the math here.

 

[azwjowner]

I looked into the bottle jacks as a more compact solution to Hilift Jacks. What I finally found is it really does not matter what extensions you buy or blocks of wood you use you need to make sure of one thing. You need to look at the amount the jack extends, which is usually 5-6 inches, and compare it to your side wall of your tire. The jack's stroke must be longer than the sidewall is high and you cannot add in extensions nor can you add in the screw thing at the top of the jack. .

If you get a flat tire and put the bottle jack under the axle tube and the jack has a 6 inch stroke you are only able to jack it up 6 inches and if the tire has a 7 inch sidewall you will be able to get the old/ flat tire off of the jeep but you will not be able to get the new tire onto the hub because the Jeep will still be too low. Stock rubicon tires have over 7.5 inches of sidewall and there are very few bottle jacks have a stroke that long.

If you have a sport model with the car tires it may work but not if you have larger tires not so much. All the extension in the world will not help you with this unless you play a musical chair game with jacking it up, using a jack stand to hold the jeep in the new position, put an extension on the jack and jack it up again.


As an alternative this one looks pretty interesting though I have not tried it yet: https://www.amazon.com/gp/product/B0D63QN5JC/ref=ox_sc_saved_title_5?smid=A29MUERPS76DU9&psc=1

Or you carry a 4"x4" block of wood (has various purposes) and shove it under the flat tire after you jack it up, then reset your jack, and continue. 30 seconds maybe?

 

[Gorilla57]

I got one of the Sprinter van bottle jacks. If I remember right, it’s 11” compressed and 25” extended. And it has a curved saddle built in. Got it for $75 off eBay and now they are $125 and up. Perfect for the JL.

 

[THAW]

Your use of geometry though it is correct in a perfect world you are "misleading" the OP in that you forgot to mention that your Geometry hack to get an extra inch of travel is far less stable/safe. The further toward the pumpkin you place the jack the heavier the load the jack is carrying because you are lifting both sides of the jeep instead of just the side with the flat. I am not worried about the jack its self because they have several tons of capacity however when you are essentially lifting most of the entire rear of the jeep with a bottle jack that only has a few inches square of base, you have a less stable set up than if your were further out toward the tire. People have lost limbs from unstable jack set ups, If this works for you that is Awesome and I wish you the best, however I like my limbs, I have had them since I was a kid

I agree stability is critically important for safety. But, there's no practical stability difference between the center of the axle tube (at ~3/4 total axle length) and it's end next to the hub; the same caution is required at either position.

Personally, I use the Safe Jack clamp-on base plate, which makes my setup much more stable than the small base of most jacks (of any type).

I also carry 2 bottle jacks for versatility and enhanced safety.

 

[Terrymo]

I got one of the Sprinter van bottle jacks. If I remember right, it’s 11” compressed and 25” extended. And it has a curved saddle built in. Got it for $75 off eBay and now they are $125 and up. Perfect for the JL.

If it’s not too much trouble and you have time could you post some actual measurements and pics of the jack

 

[Medsker]

Or you carry a 4"x4" block of wood (has various purposes) and shove it under the flat tire after you jack it up, then reset your jack, and continue. 30 seconds maybe?

This is good in theory and will work most of the time. In my case though, my last flat was when I put a railroad spike through it. As I would jack up the axle the tire would just fill up with air and reinflate. This left me no room underneath the tire to shove a 4x4 under it.

I know most people aren't going to get a railroad spike through their tire (I was on the transcontinental Train Road in Western Utah) but a blown sidewall would have the same effect. I never tried your "4x4" method when I had my flat but it would have been hard to get one under there without someone else's help and I was alone.

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