clokker

iTrader: (2)

Yeah, but they're pros and have been Board certified in jacking procedures.

Just like open heart surgery...it's fun to watch but don't try it at home.

BLKTOPTRVL

Of course, the pictures are not made to show the jack positions. The pictures are generated to describe the underside parts.

The red and blue markings are just the opinions of the poster as to where the jacks should be used, I would go with the jack positions as are actually used in the photos.

FC3Sdrift

iTrader: (5)

when your using a car lift you are sappose to put the arms on the 4 lift points on the pinch welds
its the same on every unibody car
in that picture the car is on a lift

Don49

iTrader: (3)

Those aren't stands, they're the lift pads from an above the ground lift. They are properly placed.

RADsRocket

Didn't anyone tell you that METAL on METAL slides! You have to use a BUFFER/SOFTNER such as a piece of soft wood such as a piece of 2x4 or something similar between the jack head and the cross member. A piece of thick rubber also works well such as a piece of tire tread.

Aaron Cake

iTrader: (1)

If I ever see a shop using the pinch welds to lift up one of my cars (in the rare occasion that they will actually see a shop for things like an alignment) then the result is me yelling at the service manager and then taking the car to another shop.

In my opinion, the only time it is acceptable to use the pinch welds to lift a car is if you need to do something that requires wheel removal, thus making it impossible to support the car by it's wheels. And only then if the factory designed lifting points are used, with the appropriate lifting blocks to protect the car.

I'm still pissed at all the hack-job mechanics over the years that have totally destroyed the pinch welds on my RX-7 so that by the time I bought it, the pinch welds were flattened and rusty.

classicauto

iTrader: (3)

Actually no.

Its what people do but its not right for the following reasons..

a) Its a uni body car. You are bending the frame of the car by lifintg from the rockers/pinchweld since the "frame" is intergrated into those pieces. Albeit a very small change, it can be a significant one on an older vehicle where rust is present (ie. 98% of FC's)

b) Pinchwelds minimally consist of 3 layers of sheetmetal spot welded together. Thats 3 pieces of 20 gauge steel....2 of which are not even vertical to provide the most rigidity....and you believe that to be the ideal (strongest) point to lift from as opposed to 1/8" boxed subframes?

c) The subrfames/diff are designed to keep the power of the vehicle from twisting the BODY apart. You are bypassing they're purpose by just going right ahead and bending the body.

Finally, if you're unsure about this, take your factory jack and stick it where its designed to slip into the groove on the pinch weld. Jack one side completely off the ground. Set it down. Now look at the spot you jacked and tell me whether or not its been dented at all. Not whether the mark is small, or whether its hard to tell, whether it marked it at all.

You can use a floor jack on the diff/subframe and not make a ***** in their armor all day long.

To me, and most other professionals, those are good reasons for not using PW's to lift.

black_88

isn't it possable to harm the diff mounts when useing the diff to jack the car up. seeing as how old the rubber is and then the full weight of the car is put on those three points it seams that in whould hirt the diff mounts.

FC3Sdrift

iTrader: (5)

I hear ya there i've hadto stop lots of retard shop monkeys tryin to jack my mx-3 up by te sub frame wit a floor jack and on the pinch welds

thats what i'm fixing on my rx-7....i'm goin to get rid of any rust aound the pinch welds and weld i some new metal in to strengthen them up i want the body to be solid

lax-rotor

iTrader: (1)

Just out of curiosity, how does one repair the pinch weld areas if they are bent over and shot to hell.

FC3Sdrift

iTrader: (5)

i'm goin to try and weld in some new plates vertically and tie it ack together with some new sheet metal over whatever is left of the old metal after i pick away and sand blast it


i dunno know how it will turn out
i weld on the Chevy truck frames so i can weld good
i just hope i can make it stronger and not screw it up

NZConvertible

You don't even have to do that. The lifting pad on any decent jack will have raised edges with cutouts that if properly positioned with prevent the crossmember from being able to move across it.

Aaron Cake

iTrader: (1)

Mazda sells the rocker panels and inner structure of that area. The easiest thing to do is cut out the old part and weld in new. If you are good at sheet metal fab, then you can make the parts yourself.

MmSadda

iTrader: (2)

oh, it's ON!

btw, you ask good questions for a new guy, fc3sdrift

lax-rotor

iTrader: (1)

Guess it's time for me to start practicing welding now. *Gasp*

88rxn/a

iTrader: (6)

my poor uni-body has some nice dents in it from jacks

alexdimen

iTrader: (13)

Sometimes it isn't possible to get the arms to the subframe, especially on cars with a short wheelbase. It also depends on the lift. If done properly, lifting on the pinch rails has no effect on them or the rest of the car.

The reason pinch rails get fucked up is from a floor jack being used on one side of the vehicle. First, the jack isn't just taking up 1/4 of the weight of the car. It ends up being much more than that. Second, it will push the rail at an angle as it gets up higher.

That's not to say I would ever use the pinch on a heavier body, like an F150 anything...

NZConvertible

My car's been lifted (on a proper shop lift) by the pinch welds many times and they're fine...

SpeedOfLife

iTrader: (16)

if the jack has a slot like scissor jacks do then it won't bend the pinch welded part, however most jacks in peoples' garages aren't like that.

NZConvertible

Nobody's saying to use a floor jack on the pinch welds, but shop lifts are fine. The weight is evenly distributed and the lifting pads have thick rubber protectors.

FC3Sdrift

iTrader: (5)

thanks ....i'm new to this forum not to cars lol

ninjai

when dropping out the rear subframe, where should the rear jack stands be placed?

I was going to place them on the pinch welds with possibly some rubber in between to protect the body a little bit more. Is that sufficient?

Aaron Cake

iTrader: (1)

When dropping the subframe, there aren't a lot of choices. Your only real choices are the pinch welds or frame rails. Between the two, the pinch welds (at the factory jacking points) is the less evil. Use cloths or a wood block to keep the stands from damaging the welds.

Terrh

iTrader: (7)

I have noticed over time (having jacked the car up at least dozens, and possibly a hundred + times) that the front area of the "framerail" (the two blue circles in that picture) is probably not ideal for jacking, as mine is starting to dent in slightly. In addition, (and I have no idea if it's seperate or not) but it's pushed in enough that you can notice the carpet is not perfectly flat along the floor anymore, it actually is pushed up a tiny amount on top of where the framerail is.



There are several other areas to place jackstands, and jack the car from.

I'm not sure I'd trust the tow hooks to jack from, as they're
A: not a tow hook (but a tiedown point), B: not designed for it, and C: I've ripped one of mine off, just pulling the car. (using it as a tow hook, when it isn't one)

The tiedowns (in the front) are held on by 3 bolts, and I'm not sure I'd trust my life under one, even for an instant while placing a jackstand.

schmol

For a quick tire or wheel change up front, I'll use the tow hook and for the rear, I'll us e the diff. But when I plan on keeping the car up in the air for a extended period of time, I'll still use the tow hooks to jack the car up, but will place jack stands onto the round part of the front control arms and the same placement of the stands on the rear.

As for using ramps, I place a 12" long 2x4 a 1/3 of the way up the ramp then drive up on the wood which allows the front valance to clear the ramp itself.