Flat

[Fishhunter]

Prolly a dumb question but...do you lift the weight of the camper off the truck before jacking the truck up...never had a flat in all my travels and was just wondering

[JoeChiOhki]

Buzzcut1 wrote:

Kayteg1 wrote:

JRscooby wrote:

Kayteg1 wrote:
10 tons?
I wonder what it takes to bend the axle?

What does it matter? The jack can't put any more force than what the axle weighs, no matter the capacity..

It does matter when you put the jack under the axle pipe, like most of us do. When you have axle overloaded and lifting it in the point that was not design for it- something will give, just like Titanic broke on several pieces as it could not hold its own weight hanging in the air.

If your axle cant take a jack lifting up a little more than half the load that it normally carries down the road then I would say you are driving junk. Seriously we are only talking 4-5000 pounds.

The difference is in pressure to area applied. Your spring perch transfers the load across the curvature (the strongest part of the tubular structure ) if the axle tube.

With a smaller bottle jack you're concentrating all that weight into a much smaller contact patch, which increases the psi being applied and can damage the tube potentially.

In terms of total weight, that part is moot, the psi at the contact patch is the critical bit.

If you look at most factory jacks, they use a cradle which spreads that contact patch out into the curvature of the axle tube, reducing the total psi, but they are generally only rated fir lifting an unladen truck, not one with a full load in the bed.

[Buzzcut1]

Kayteg1 wrote:

JRscooby wrote:

Kayteg1 wrote:
10 tons?
I wonder what it takes to bend the axle?

What does it matter? The jack can't put any more force than what the axle weighs, no matter the capacity..

It does matter when you put the jack under the axle pipe, like most of us do. When you have axle overloaded and lifting it in the point that was not design for it- something will give, just like Titanic broke on several pieces as it could not hold its own weight hanging in the air.

If your axle cant take a jack lifting up a little more than half the load that it normally carries down the road then I would say you are driving junk. Seriously we are only talking 4-5000 pounds.

[jimh406]

I started carrying a 12 ton bottle jack a few years ago. I would use it instead of the factory jack, but the real answer is I’d probably just call AAA if possible.

One of the reason I bought a 450 is for the 19.5 tires which I feel are much tougher than a normal tire. Hopefully, it means no flat.

[kohldad]

Just use the factory jack. Used it on loaded truck, loaded flat bed trailer, among other things. Only time I can remember changing a tire with a bottle jack was on the road when my single axle dump was overloaded with 11 tons in the bed. The 8-ton bottle jack said that was about all it was going to pick up but did get the job done.

Besides, I don't really have the room to carry an extra bottle jack. Space is all taken up as it is and I'm already heavy enough.

[Kayteg1]

JRscooby wrote:

Kayteg1 wrote:
10 tons?
I wonder what it takes to bend the axle?

What does it matter? The jack can't put any more force than what the axle weighs, no matter the capacity..

It does matter when you put the jack under the axle pipe, like most of us do. When you have axle overloaded and lifting it in the point that was not design for it- something will give, just like Titanic broke on several pieces as it could not hold its own weight hanging in the air.

[specta]

That settles it. I'm getting a 15-ton bottle jack. :B

[Buzzcut1]

I carry a 12 ton bottle jack. Blew an inner dual at night on I5 with my loaded horse trailer in tow and 4600# lance in the bed. I chocked my wheels and jacked the rig up. No unhooking the camper. ( no way I was going to be out in traffic with a foot to the fog like messing with fastguns and locks). Had the spare on and was on my way in 45 minutes (including unbolting what was left of the dually fender).

[JoeChiOhki]

JRscooby wrote:

Kayteg1 wrote:
10 tons?
I wonder what it takes to bend the axle?

What does it matter? The jack can't put any more force than what the axle weighs, no matter the capacity. But lifting 12,000 lbs with a 6 ton jack is more of a workout than with a 10 ton jack.
Don't think it matters much on little stuff but I once bought a truck that had about a 2 inch round hole in the bottom of the axle housing. Pulled the Diff, found the piece. Somebody had put a jack under the flat part of that 20,000 lb rated axle.

On my tool truck I carried a 2 foot long piece of truck frame too put under my jack if needed. Overkill for RV, but if I needed to lift the end of axle that might have 30,000 on it while setting on dirt I had a place to start.

Somebody mentioned the miles you haul a jack, and don't use it. Best if you keep the jack upright, even when not in use.

10 ton jacks usually also tend to have a larger contact patch on the axle tube than the smaller 6 ton jacks do. Ergo why I mentioned the high heels effect, where weight concentrated into a very narrow contact patch can create excessive PSI on that point and in the case of an axle, possible cause a deformation in the form of a flat spot in the tube or concavitation.

In this case, the difference is between putting a chunk of 12,000lbs on the contact patch the size of a quarter vs an old school silver dollar.

[JRscooby]

Kayteg1 wrote:
10 tons?
I wonder what it takes to bend the axle?

What does it matter? The jack can't put any more force than what the axle weighs, no matter the capacity. But lifting 12,000 lbs with a 6 ton jack is more of a workout than with a 10 ton jack.
Don't think it matters much on little stuff but I once bought a truck that had about a 2 inch round hole in the bottom of the axle housing. Pulled the Diff, found the piece. Somebody had put a jack under the flat part of that 20,000 lb rated axle.

On my tool truck I carried a 2 foot long piece of truck frame too put under my jack if needed. Overkill for RV, but if I needed to lift the end of axle that might have 30,000 on it while setting on dirt I had a place to start.

Somebody mentioned the miles you haul a jack, and don't use it. Best if you keep the jack upright, even when not in use.

[Kayteg1]

10 tons?
I wonder what it takes to bend the axle?

[JoeChiOhki]

I just use a 10 ton hydraulic bottle jack with a wide contact patch (to not create the high heel effect on the axle tube), some 2x6 boards and jack it up directly beneath or as close to the spring perch as possible.

[jaycocreek]

They have bottle jack adapter saddles for axles making it safer for those that want them..

[Fuller_Johnson]

Couple years ago I was going up to the UP with my 95 Dodge Dually and a tandem trailer loaded and went through a sealcoating operation and picked a couple screws in the outside dual. Didn't know anything was wrong until I stopped for fuel and smelled Hot Rubber. Just took the factory jack from under the seat, Jacked it up and changed the tire. Threw the old tire on the trailer and went the rest of the way. Factory jack picked up the truck, Camper and tongue weight just Fine.

[JimK-NY]

When I had Rickson ship me 19.5 wheels and tires, I wanted a good jack to use for the install. I had a difficult time finding anything suitable. The typical bottle jack has a small cylinder for lifting. That would not be safe for lifting a round axle. I finally found a jack with a cradle but it is huge with a large base. No way would I have space or want to carry it for the rare chance that I might need to change a tire on the road.

Can anyone recommend a suitable jack or modest size with a cradle for secure lifting? Even then I would need to think twice. In 10 years and 100k miles, I only had one flat and AAA changed that for me.

[JRscooby]

jaycocreek wrote:

specta wrote:

Hemi Joel wrote:
I carry an 8 ton bottle jack and some wood blocks. I've changed tires a few times on the road. I just leave the camper on the truck, I don't lower the camper jacks, chock the other wheels, put the bottle jack under the axle tube as far outboard as possible, change the tire, lower the truck. Never had an issue with that method, never saw a need to do it any different.

Best answer so far.

This^^^^^...I've changed way more than my share of the inside dually of a loaded logging truck in some tuff places this way...It just works..

The issue is most bottle jack (IMHO, best idea) is you must be under the vehicle to work the jack. With the wheels off, this is a real safety issue. That is why I say pull the flat up on block first. Gives more room to work jack, less work for jack to do, and if the jack slips you have more room after the fall. Once the weight is off the block, remove it and the flat. You know you can put the spare on without more jacking.

mkirsch wrote:
In my case I used the tongue jack of the trailer I was towing in conjunction with the 2-1/2 ton floor jack I keep in said trailer to change the flat I had a few years back.

A floor jack can be great; Don't need to be under to operate, and lots of travel to lift high enough to easily change. The issue is most times you need to change a flat you are missing a major part needed, the floor. Look at the way the lift platform goes up. It travels in a arc. Not a issue on a smooth floor, because the base rolls under the lift point as it goes up. But on even something as hard of asphalt, or rough surface concrete, there is a very real chance the lift pad will slide on load instead of the base rolling.

This discussion is good, might point out problems you don't know you have. IMHO, everybody that drives should pick a nice day to learn. With what you have in the vehicle, can you loosen the lugs? Can you chock a wheel to jack another up? Know where to put the jack? Can you lower the spare to ground, move the pickup, or do you need to drag it out? My point is know what you need to do to change the tire so you don't need to learn in the dark, cold, rain with traffic going by.