Placing a jack under an I-beam axle...?

I saw a post the other day of a car equipped with a drilled I-beam axle that had a floor jack positioned under the center of the axle.

Over the years, I've done it myself on my own ride (not drilled) and I'm wondering if anyone can tell me if they'd ever bent their axle and thrown the camber off.


JOE

 

I'd like to know also...bttt

 

ive seen alot of axles with what seemed like excessive camber that i always related to just this fact, maybe sitting for a long time on a jack or stands
no proof though

ive stuck a few in a hydraulic press and bent them in the middle

the roads are flatter now days i believe, so you dont need the same camber as ford put in them to compensate for the curvature????

 

I have jacked mind many times by the axle and not bent anything. I'm guessing the cast axles like Magnum would be more prone to that, rather than the forged Henry Ford steel originals?
Would be nice to know if it does happen though!!
Doc.

 

I sure hope not,,I've done it many times,,,it sure takes a lot of heat and a press to strighten one when it's bent, HRP

 

If the axle would bend from being lifted with a floor jack, then it would also bend from driving on a bumpy road.

In both cases the weight of the car is the only load on it.

 

the drilled 32 heavy beam in my 28 doesn't care where I stick the jack. They are TOUGH.

 

If it bent from that, it would have killed its first owner by 1933 at the first unexpexted pothole it met...there wouldn't be any left to vex this generation.

 

I kinda disagree. When the car is on it's wheels it's weight is divided by 2. On a jack it's weight is on one point. I know putting a penny on a phonograph arm to keep the needle from skipping will increase the pressure to a point that it will ruin a record, due to the same phenomenon.

Also, the geometry is different from the wheel to the spring perch (maybe a foot) than it is from the axle's center to the perch (about 2 feet).

I know from dirt racing that "weight jacking" is jacking one corner of a car higher than the rest. This places more of the car's weight on that wheel, so raising the car on a jack places more weight on the raised end... I'd think.




JOE

 

I straightend a model A axle on a 70 ton press, I had to go about 1/2 in. before it wouldn't spring back, and that was in the opposite direction as you would if jacking it up.

 

Actually a good question............I have done it but never thought of this.

 

Been using the jack in the middle of the axle on both the 32's tubular axle and the 31's beam axle - both SuperBell - for some time now.

I only leave the weight on the center long enough to get the jackstands under.

So far, no probs.

 

Mine is an original Ford dropped by Dago many years ago. I drilled it, 1" holes spaced 2" on center. I have jacked it up many times from the center and to date no perceptible changes in the axle or camber.

 

Never bent mine and the Anglia axle is VERY thin and spindly

 

They are very tough, with alloy steel and elaborate heat treat. I think only suspect part that could bend without enough violence to move things a LOT would be the end areas of hot rod dropped axles, where the heat treat has been destroyed by the heat necessary for the bending.

 

My Dad (long gone now) was a frame/suspension man for about 50 years. He bent beam axles pretty much on a daily basis in order to effect correct alignment.
In a lot of cases this was done as part of the collision repair and almost always in conjunction with his having to straightening the frame. It was also necessary on some cars/trucks from serious driving abuse such as bad roads, service use of trucks/pick-ups, etc.
NORMAL driving on modern roads that are infinitely better than the roads "back then" is extremely unlikely to damage a beam axle, nor is jacking up the front of a hot rod that typically ways 3,000 lbs or less (not all of that weight carried on the jack, either).
If your gonna do the Baja 1000 with a beam axle your gonna have problems!!!! Otherwise, unless the strength of the axle has been compromised to the point of being so week as to be at risk of bending under normal conditions, I doubt you will have any worries with a floor jack.

Rich

 

Geez . . . got to thinking . . . dangerous, I know, but, if the axle was bending with the jack in the middle, maybe those killer potholes we hit once in a while are straightening it back out?

Course the trick is to not jack the car up until you hit a pothole so that it all comes out even.


I note that the Arizona highway folks measure potholes by depth and length.

I measure em by how many lanes or parts thereof the 32 moves over.

Sumbitch . . . we were headed north weren't we?

 

If your axle bends from a jack being under it, your holes are too big.

 

The force you put on it while jacking it up is nothing to big right? If it bends while being jacked up it should explode when driving.

 

If you have EVER watched an alignment sop do thier work on one,,, you will never worry again about simply jacking it up. They chain near the perches and jack up the center and you can see EVERYTHING straining to move it.

 

I think I gave my drilled Magnum the test. Hit a piece of lumber at freeway speed last year & sent the car several feet airbourne (felt like 6 feet). Blew one front tire but the axle was ok. Can't say the same for the 4 pc hood, cowl or the upper shock mounts that tore out of the frame.

 

Forgive me .... But isnt the fact the axle is attached to the spring ( rather than a solid mount ) going to reduce the load that is being applied ? And the fact the whole front end is acting as a lever and displacing weight further down the frame in the first place ?
So really the only way it could happen is maybe in a drag car after standing it on its arse and bottoming out the front spring on returning to terra firma ......

 

Do you realize how many people here have no idea what you're talking about?

 

To be clear... I was asking about drilled axles.

To reiterate what I brought up earlier, the forces on a car that is in normal use and stance are much different than the force applied to a single point under the center. Also, the curvature of the axle allows it to "spring" downward in the center under normal use... the opposite might apply when force is applied to the bottom of that curve.

I have never had a drilled axle, nor have I ever drilled one. That's why I'm asking.

I'm in the metal fab/repair business and I see bent and distorted metal all the time. Things are possible.
After all... it's ONLY metal...


JOE

 

Meaning...?





JOE

 

I do understand what you are saying , And I am making the point that the weight is still supported by the spring and the front end to the point where it attaches the frame ....

 

I don't know... weight is weight. I don't think the load on the axle or the spring will change regardless of where the pressure is applied from below (on the two wheels or on the jack)
I think the only difference the spring makes in this equation is when the jack is let down and if it were to bottom out on the jack.

I think if you put the jack under one wheel it will raise one wheel slightly before lifting the car, but under the center I think it will pretty much take the whole front end up.

Maybe I'm wrong... I guess I'd have to jack up my car to see how it acted.


JOE

 

You need to buy a second floor jack, that way you can place one under each spring pearch and safely jack up the front end.

 

Ha ha ... But no , your not thinking outside of the circle .... You could change the head on your jack to one that lifted at two points a couple of feet apart !

 

I'd say he ment, Put a penny on a record player arm to keep it from skipping.

As for Bending an axel from lifting it at it's center with a jack ?
They rest on the center all the time at the spring pirch, and receive a shock load from bumps in the road.

They have to be able to withstand hitting a hole with one wheel only ( or uneven stress ), the leverage created by the length of the axel from the wheel back to it's center would be enormus compaired to lifting with a jack.

If your going to have a problem or bend the axel... I think it will be when your on the road carring more weight ( driver +) and hitting the common big pot hole.

We were talking about a car on a buggy spring, weren't we ?

If it's with parallel leafs ? I can see your point, but still the axel stresses would be much greater under road conditions than lifting with a jack.