240z Jack points

[87mj]

According to the owners manual, we are suppose to be able to jack up a 240z at the jack points along the rockers.  I did this back in the late '70s with my '73.  Then I tried again in the mid '80s on my '72.  They were both unrestored cars that lived in northern Indiana.  The sounds that were produced by thin rotten 20 gauge steel still haunt me to this day.  I am sure the titanic sounded similar as it went down.

My current car is a mint condition '71.  Its frame is as solid as the day it came off the line.  Still, I am reluctant to use the jack points.  Honestly, I am reluctant to even try.   240z sheet metal is very thin. 

In the front, I jack up on the reinforcement on the front axle.  On the rear, I jack it up at the rear dif using a hydraulic jack and a block of wood as an insulator.

My son claims the rear dif is aluminum and that I am asking for trouble by using that as a jack point. But that is how I did it with my other two 240z's. Do any of you 240z owners jack up your cars at the jack points or do you jack them up at that axles as I do?

I am not sure but I think this question only applies to 240z owners.  They thickened the steel on the 260/280z if I recall correctly.

Thanks

 

[Jeff G 78]

On a hoist, I'll use the rocker pinch flanges, but even on a rust-free Z, I use the same points you do.  The diff isn't the best place to lift though since it stresses the mustache bar bushings.  If you have poly bushings, it shouldn't do any damage.  As for the diff, only the rear cover is aluminum and there is zero chance of damaging it.  The mounting bolts are in shear.

[SeafireXV]

There are six factory approved jacking points on a Z. The four points on the rocker panels, the front chassis cross member for lifting the front wheels, and the diff for lifting the rear wheels. As long as the  body is not rusted to the point of failure there are no problems with using the diff as a jack point, and you should never lift the car using any other jacking points.

[87mj]

I have seen 240z's sitting on hoists where the host stands are sitting on frame rails right behind the wheel wells.  I would hesitate to do that too.  Anyone else?

Edited December 31, 2015 by 87mj

[Zed Head]

There are actually ten support points ID'ed in the FSM.

Edited December 31, 2015 by Zed Head

[rossiz]

why not use the frame rails? i always use the hydraulic floor jack under the front cross member and at the rear i use the diff mount, then i set the jack stands under the frame rails.

am i doing something wrong??

[Jeff G 78]

The rails on pretty much every S30 are dented for just that reason.  You'd think they would be strong enough, but they are not.  They will crush if used to support the car.  Even on rust-free cars, the rails are weak.

[HuD 91gt]

Am I the only one who can't understand the manual diagrams?

 

The front I use the crossmember.  The back, i've always used the small, let's say 2" wide frame rains which run to the sides of the car from the diff area.   But yes, mine are dented

[Jeff G 78]

Yeah, the pics are too grainy to tell where the jack stand points are.  I put jack stands right at the LCA pivot point of the front crossmember and the rears on the crossmember just outside the front diff mount.  I angle the rear stands to match the angle of the control arms.

[rossiz]

yes, my rails are dented - i figured a PO used a hydraulic bottle jack and put the jack head right in the middle of the flat part of the rail without any wood or metal to spread the load. my jack stand support cradles reach around so the support is on the corners of the rails, using the vertical part of the metal vs. the horizontal. hasn't been an issue for me, but again this is support, not jacking... my floor jack has a wide disk and i always put it under the center of the car to lift (front crossmember, rear diff support) and don't ever jack from a corner of the car. the reason is that i notice when the car is up on stands the body flexes enough that the door seals hit the the body trim up at the top - the car basically bends about 1/8" or so. it straightens out when it's back on the wheels, but i never wanted to lift one corner for fear of introducing a twist into the body. never had a car do this before, but just assumed it was the thin sheet metal and lack of full frame. is this common w/these cars, or should i be worried? there isn't any rust in the body or rails that i can see.

[Mark Maras]

 

 Yeah, they flex a lot. Almost all Zs show signs of it above the quarter windows. The tell-tale crack in the paint. I did notice in my original that after bolting in a rollbar the rear seemed stiffer. Never did brace the front. That's where it really needed it. 

[Carl Beck]

Thin sheet metal does not equal “weak”. It equals “lightweight” if anything. The 240Z body doesn’t flex because of thin metal.

 

Uni-body flex is more a matter of the exact design of the structural components, the specific grade of steel used and how well it is all welded together. There is a good reason  Race Cars are “seam welded” for example.

 

Agreed that rust damage to structural components can weaken the uni-body.