Why not jack trailer under the spring plates?

[opnspaces]

For years people have asked where to place the jack in order to jack up a travel trailer. And people always say do not put the jack under the spring pack. This has bothered me for years because it doesn't make sense to me. Now I'm not an engineer by any means. But could somebody please explain why under the spring pack is bad? I mean look at the pictures below. In an under slung axle the entire weight of the trailer looks to be on two very small u-bolts. Am I wrong? It seems that the u-bolts are holding the weight. If the thin u-bolts are holding the weight.and the spring is on a thin perch welded under the axle; How is jacking at that point going to be a problem?


And in a travel trailer with over slung axles putting a block, or even a floor jack under the axle seems like it would be okay. The axle tube is thick enough to hold the trailer in the air with the u-bolts on top. Are we saying the tube is thinner on the opposite side of the axle tube?

[Grit_dog]

opnspaces wrote:
For years people have asked where to place the jack in order to jack up a travel trailer. And people always say do not put the jack under the spring pack. This has bothered me for years because it doesn't make sense to me.

That info is only propagated by the rvnet peanut gallery afaik.

[opnspaces]

Well at least it's good to know that I'm not alone in jacking from the spring pack.

[valhalla360]

red31 wrote:
I find the frame easier to access than what is behind a wheel.

But twice as high, so more likely to have the jack tip over.

[valhalla360]

rdhetrick wrote:
one of the bolts holding the springs could fail.

If one of the U-bolts fail when jacking on the plate, something was already seriously wrong. The forces on those bolts when you hit a pothole at 65mph are likely dozens of times higher than slowly jacking up an axle.

Now if the axle is below the springs, you may run into an issue of finding a nice flat area to lift as both bolts and axle are round.

[Veebyes]

15 years of jacking under the bottom spring leaf right next to the axle. Can't imagine doing it anywhere else except when needing to change a spring pack.

Simple & safe. The bottle jack is lifting at a flat surface.

Lifting under a U bolt is asking for trouble.

[StirCrazy]

wa8yxm wrote:

fj12ryder wrote:
I believe if you do some checking, it's the manufacturers that say not to jack up the trailer by the axles and use the frame instead. But, IMO, that is a simple CYA. If they said it was okay to use the axle, then some nimrod would end up jacking in the middle of the axle so they could lift both sides, or some other moronic reason, and then complain when the axle bends: "But it said I could use the axle to jack up the trailer. It's not my fault".

You know what sir.. I think you just NAILED IT.

Yup. And I've read stories that fully support the "Then some nimrod..."part of your post.

does it spicificly say for changing tires and such, or when they talk about jacking from the frame are they talking about for leveling/stabalizer blocks.. I don't ever remember anything about jacking to fix a flat or what not but I'l double check, may have glossed over that section thinking " who doesn't know hot to jack a tire for changing"

[Dutch_12078]

I've been jacking up various trailers, including OTR trailers, for over 60 years. About the only times I don't use the spring pad is one, when the springs are what I'm servicing, and two, when the jack doesn't fit under the pad due to a flat or blown tire.

[wa8yxm]

fj12ryder wrote:
I believe if you do some checking, it's the manufacturers that say not to jack up the trailer by the axles and use the frame instead. But, IMO, that is a simple CYA. If they said it was okay to use the axle, then some nimrod would end up jacking in the middle of the axle so they could lift both sides, or some other moronic reason, and then complain when the axle bends: "But it said I could use the axle to jack up the trailer. It's not my fault".

You know what sir.. I think you just NAILED IT.

Yup. And I've read stories that fully support the "Then some nimrod..."part of your post.

[Mike134]

Lwiddis wrote:

Sounds like the same 'internet' rumors that get passed down from generation to generation.. 🙂

Mitch

Forums are the 2022 version of the advice you used to get at your favorite saloon.
If you think it's any better because it's from the internet I have some real estate to sell you.

[MitchF150]

Lwiddis wrote:
If under warranty and you Jack from springs when manufacturer says no and something goes wrong…no coverage.

Well, any 'warranty' can be denied for any reason... So, in the end, do whatever method works best for you and your situation...

If you are unsure, or unable to physically do this, probably best to have some sort of 'road side assistance' coverage so you can just call someone to do it.. 😉

Sounds like the same 'internet' rumors that get passed down from generation to generation.. 🙂

Mitch

[Pbutler97]

Lwiddis wrote:
If under warranty and you Jack from springs when manufacturer says no and something goes wrong…no coverage.

If you do anything expecting to have coverage under warranty, good luck with it.

If the manufacturers worked as hard at building RVs as they do at coming up with all the red tape in their warranty documents, no one would need a warranty.

If you have an issue with frame, especially if its LCI, they'll claim overload before anyone even looks at it. If your roof leaks they'll claim lack of required maintenance. When the pleather furniture peels they'll refer you to the manual where it states its only meant for "part time" use. They're good at denying warranty claims and have decades of experience screwing the buyer.

[Lwiddis]

If under warranty and you Jack from springs when manufacturer says no and something goes wrong…no coverage.

[MitchF150]

I know this is all about jacking rigs with leaf springs... That's why I like my torsion suspension setups I've had on the only 2 rigs I've owned for the last 20 years..

This is my old 2003 Prowler Lynx TT. What you don't see in the pic is the jack stands on either side on the frame as well. The bottle jack is just there to get the tires off the ground initially and then I put the stands under and release the jack so it's just there to jack up again to remove the stands..

Anyway, I've done the same on the Rockwood, I've just gotten a larger bottle jack cause I needed more extension on the pistons..

And NO, the frame is NOT bending... It's just the way the picture came out.. 😉

Mitch

[Alan_Hepburn]

I've never heard anyone say not to use the spring perch; on the contrary I've always heard to use the spring perch as opposed to using the axle tube itself.

[red31]

I find the frame easier to access than what is behind a wheel.