Placement of jack for lifting

[sepezlover]

Ok, am I correct that that vertical plate with the D-shaped holes is the axle mounting plate? That what it looks like the jack stand is on in Splitrock's picture. I put my jack on that, in between the wheels, and the plate bent. What am I doing wrong?

[Splitrock]

Right place, wrong jack me thinks. Get a bottle jack. Your jack has to be on concrete and free to roll as it goes up and down.

[sepezlover]

Thank you, now it makes sense. It warped because the jack couldn't roll as the trailer tipped. How big a bottle jack does it need to be? I assume they come in more than one size. And any ideas on how to bend back the warped plate?

[barts]

Even the smallest hydraulic bottle jack will lift your trailer.... my 12 ton jack laughs lifting less than 2500 lbs, which is what our tradewind weighs per side.

How much of the plate is bent?

- Bart

[Inland RV Center, In]

Originally Posted by dorfgog

Ok, am I correct that that vertical plate with the D-shaped holes is the axle mounting plate? That what it looks like the jack stand is on in Splitrock's picture. I put my jack on that, in between the wheels, and the plate bent. What am I doing wrong?

Attachment 122586

Look at the back side of the axle mounting plate, where it's welded to the bottom of the frame.

The welds do not need to make a complete "seam", but back then, all to many times the distance between the welds were 8 to 10 inches. That then allows the axle mounting plate to bend in those areas, since there is no additional strength added to that area.

Usually, when the absence of weld is the problem, "C" clamping the frame to the axle mounting plate, in those areas, will bend the plate back into position so that it can be welded to prevent the same problem at a later date.

If you don't weld it, it will get worse, in time.

Andy

[Alan3940]

Does anyone have a picture of the correct jack placement on a late model tandem axel?

[tpi]

This is not my picture, got it thru google image search. The jacking is the same on late model trailers. It is very easy to lift trailer using bottle jack on axle mounting plate.

[halimer]

The above photo is how they do it at Jackson Center.

[2airishuman]

really?

wasn't how they jacked the 34 ftr,

or any other trailer in the service bay during my visits.

well, during my 2dozen visits.



with picture proof directly from the j/c shop floor in post # 42 below...

Originally Posted by Alan3940

Does anyone have a picture of the correct jack placement on a late model tandem axel?

this lengthy thread may help U (or just muddy the issue)

http://www.airforums.com/forums/f457...tml#post428907

there is also a picture/drawing in the a/s owners manual.

while is is rumored here that the factory folks and manual writers are wrong and don't know HOW 2 jack...

i tend to believe that they DO know jack on this issue.
________

the green 'bottle' pic above is right here too, in that thread.

while mr greeeeen is technically a mechanical screw jack,

which have been used 4 over a 100 years in construction, railroads, house leveling and so on...

SELDOM (never really) are they used to 'jack' autos, trucks, OR rvs.

the bar used to rotate the head is long and heavy and usually will not clear the wheels or other dangly bits.

so typically a hydraulic jack is used to LIFT,

and the bottle/screw is used 4 a safety stand, or long term support after lifting.

and in that application it becomes a jack STAND, like the more common ratcheting variety.

cheers
2air'

[sepezlover]

Here are some pics of the damage to the axle mounting plate. The other side is similar. The main thing, it seems to me, is that the shock absorber mounting bolt is tilted upwards. Is there anything I can to to try to bend it back straight, or just leave it alone?

[Inland RV Center, In]

Originally Posted by dorfgog

Here are some pics of the damage to the axle mounting plate. The other side is similar. The main thing, it seems to me, is that the shock absorber mounting bolt is tilted upwards. Is there anything I can to to try to bend it back straight, or just leave it alone?

That bend in the axle mounting plate won't hurt the shocks at all.

Andy

[sepezlover]

Originally Posted by Inland RV Center, In

That bend in the axle mounting plate won't hurt the shocks at all.

Andy

So, Andy, as long as there is no separation between the mounting plate and the frame, should I just leave it alone?

[Inland RV Center, In]

Originally Posted by dorfgog

So, Andy, as long as there is no separation between the mounting plate and the frame, should I just leave it alone?

Of course.

Don't look for a problem, when there is none.

So the axle mounting plate is bent, so.......... It not hurting anything.

Andy

[sepezlover]

Yaaaaaa, good news for once! Thanks to everyone for the help