how do I use a 4x4 to support the front end?? (Page 2/2)
fierosound JUL 24, 10:43 AM

quote
Originally posted by imacflier:

Does anyone see a problem with placing the support beam across the forward (just aft of the front tires) yellow rectangles labelled Frame/Body Contact Hoist?




I have always put jackstands in those locations and the car is not going anywhere. A 4x4 would be redundant.


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Dennis LaGrua JUL 24, 12:02 PM
As for the picture of the railroad trestle, yes they sometimes use wood but those are specially cut 12 x 15 beams. At professional shops you never see wood used to support a car? The OP is free to do it his way but I would recommend going with what the pros use....steel.
pmbrunelle JUL 24, 01:26 PM

quote
Originally posted by Dennis LaGrua:

As for the picture of the railroad trestle, yes they sometimes use wood but those are specially cut 12 x 15 beams. At professional shops you never see wood used to support a car? The OP is free to do it his way but I would recommend going with what the pros use....steel.



Professional auto repair shops are in the business of repairing many different cars... hence they drop the cash on an off-the-shelf lift, because they don't want to waste time figuring out how to lift cars.

The Saturday mechanic at home has more time than money, and maybe just one car to lift, so the solution space is different.

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Larry, to make sure we understand what you want to do, does this diagram accurately represent what you have in mind:

[This message has been edited by pmbrunelle (edited 07-24-2020).]

imacflier JUL 24, 02:05 PM
pmbrunelle

Yes! That is EXACTLY what I intend....with the rear tires on a ramp.

Larry
cvxjet JUL 24, 02:22 PM

quote
Originally posted by dremu:

The smart ass part of me says "How are you going to get a big honking truck like a Blazer or a Bronco under a Fiero?" (You said "4x4" ...

-- A



I read your line and thought of......



I just find convenient places to use my (Safe) jack stands....wider is better.....I usually lower it till it is on them (But the jack is still close) and then grab the car and pull/push on it to test solidity before sliding under- Mainly afraid if it fell that my hard head would damage my car!

[This message has been edited by cvxjet (edited 07-24-2020).]

pmbrunelle JUL 24, 03:12 PM

quote
Originally posted by imacflier:

pmbrunelle,

OK, since it looks as if you have the skills and data for analysis: what about using RMP Hot Rolled Steel Channel, 2 Inch Width x 1 Inch Leg Length, 1/8 Inch Thickness (3/16 inch Thickness is also available). It would sure cut down on the bulk....and since I have rain for a few days....

TIA,

Larry



I guess you want to put the widest flat face against the bottom of the car? Too small... what else do you have laying around? Square tubes maybe?
imacflier JUL 24, 09:20 PM
pmbrunelle,

Since my tech training all lies in aerospace electronics and nuclear power, I absolutely do not know know diddly about statics....I seem to recall that is the term....but mebbe not!

And I absolutely do not intend to challenge or offend you (a lesson learned the hard way as a program manager dealing with my project engineer).

Still, it is counter-intuitive that a 4x4 beam which has been demonstrated to sufficiently support the heavy end of the car is insufficient for the light end!

So, lets start again: it is clear you understand what I want to do. What size/shape of structural steel (still seeking compactness!) would you recommend that I use? I am gonna have to buy it anyway, so I would druther buy the right stuff!

Very warm regards,

Larry
pmbrunelle JUL 25, 12:49 AM
Usually the 4x4 in the rear is touching the floorpan for most of its length, with the spaceframe directly above the jack's lifting pad. In this case, the supports are off to the sides, and not directly underneath the spaceframe. Therefore, I feel that the two situations are not comparable, so we cannot use our experience with one situation and apply it here. Also I am a bit conservative with my suggestions because I do not want to be responsible for giving a bad recommendation resulting in death/injury.

I will look into the suggestion for a steel piece tomorrow. It is not the kind of exercise I want to screw up doing late at night.
pmbrunelle JUL 25, 11:46 PM
For steel, I suggest a 4" square tube, 1/4" wall.
Maximum span: 90"

A bit of head-scratching will be required to figure what how the beam should be supported by the jackstand (or other support).

You may need to weld something to the bottom of the beam to make sure it doesn't slip on the jackstand.
imacflier JUL 26, 08:38 PM
pmbrunelle,

Thank you so very much for all the efforts.

Since I will save no bulk, and spend more, by using steel, I will simply give up on using a beam and try and work around my jackstands (sheesh).

Thank you again....and all who contributed,

Warm regards,

Larry