Captain caveman

I was working underneath my car today pulling out my alternator and noticed these two beams on my car. The first pic is on the right of the car and is rusted through. The other pic is on the opposite side of the car and is heavily dented. Are these beams part of the chasis. If so, should I be pretty worried about this then

Fast240Z

I believe that is either your subframe or a support brace.

lww

Yup, those are the floor rails. They are boxed for added rigidity, but there really isn't a 'frame' on these cars. That's why they call them 'uni-body' construction. All the panels interlocked together provide the support rather than a dedicated rigid frame. With the exception of the engine bay. (The motor is mounted to a rigid sub-frame) This type of construction also contributes to a certain amount of flex in the body of the car.

Go to http://www.datsunzparts.com/ and you can buy just the rails for $80 or you can get the floors and rails together for $299.

With as much rust in that rail, I would pull up your carpet on that side of the car to make sure it hasn't rusted through to the interior.

Skully

haha looks like you went under my car and took a pic!!! awsome...

Captain caveman

it's only the rail that is damaged. I just put new carpeting in last week, so my floor pans are just fine. That's interesting though, I didn't know about uni-body until now. Thanks

Another thing, when I'm jacking this car up what's a safe spot to put the jack at? In the front I've been putting the jack under a beam under the front to get under the engine bay. What about on the side of this car?

Bleach

The factory manual says to put the jack on those main 'frame rails' but they also say you have to put a 2x4 under the car to spread the weight out a bit. Someone put a floor jack directly on your rails there and dented them. The same was done to my car but mine is a little less rusty.

The 2x4 should be about 1 foot long or longer. 30+ cm for Skully.

ZedZilla

pretty much the same as my car as well. might even be a bit better. i think I got me a couple of "go faster" holes (thats cool speak for rust holes for all you lucky southerners) down there as well. frame rails bend like cardboard...i just left them there for looks for now until i change them

I used a 2x4 2 feet long to try and spread the weight as Bleach says...it helped a bit. What I found worked out better then the regular jack was the rolling hydralic jack placed past the floor rails where the front frame rails connect to the firewall area (hard to explain i guess) and where the rear suspension mounts join the rigid mounts. when up high enough you can place jack stands at appropriate areas to support the car. Lifted the car up on all four using that when I was working on the suspension, brakes etc