When exactly did rear sway bars begin being installed on 240's? I had thought they started with 260 (74 in USA). These two '72's I have here have me confused. One has nothing in the rear. The other has a rear-oriented sway bar installed AND as I was lurking around underneath noticed the brackets for a front-oriented bar are installed. Just the brackets (you know, the two pieces of metal welded to the frame, one with a slot for the retainer and the other threaded). So here's my questions:

A. Why would these (front-oriented) brackets be installed (they look EXACTLY like the ones on a 280)?

B. I am assuming both a front-oriented and rear-oriented sway bar would use the same holes in the control arms for end placement. BUT: If a custom sway-bar end rod could be created (and it seems easily possible if opposing deflection is not an issue) could TWO sway bars be installed on a 240? Would the geometry oppose each other? How much fore-to-aft deflection occurs at the sway bar mounting points? If there is a measurable amount of aft-deflection occuring at the rod ends of a rear-mounted end point and a measuable amount of deflection occuring at the ends of a forward-mounted end point, obviously they would fight each other and create an unsurmountable stress point at the rod ends.

Kinda thinking out loud.......any thoughts?

steve77

Wasn't there a US aftermarket rear anti sway bar kit available at one time which was mounted rearwards? Without thinking too deeply about the subject, it seems that it makes no difference theoretically whether a bar is mounted to the rear or front. Either way the bar reacts to suspension movement in the same way.

BTW, the stock anti sway bar mounts are entirely inadequate, they flex significantly under working loads.

I believe they were made standard somewhere in the 72 model year. My 73 had the front mounts but no bar, but the one 72 I have here has an aftermarket rear mounting bar on it. Don't know about the other one in the backyard and it's too wet to go crawling under it to see...

The front mounting bars are the ones the factory put on, the rear ones are the aftermarket supplied bars. Nissan Comp had both depending on whether your car had the front mounts or not if I remember right....

No sense in having two... two small ones aren't going to act any different than one... it's the size of the bar that matters.

Guess we could do a little detective work with Vin numbers and see about when the front mounts were put on the chassis, as the production changes on zhome doesn't say anything about the rear sway bar.

... it's the size of the bar that matters.

That's what she said.

are we saying that we dont need both(at same time) sway bar in front and the back of the car?

No, "we" are saying two in the rear makes little sense. One on either end is fine if you choose the sizes correctly and don't overdo it and get bars that are too big on the front or rear as it will adversely affect the handling.

I used to own a 1973 240Z, HLS30-150712 (mfg 3/73) and it had no factory supplied sway bar mounts in the rear of the car at all. I have always thought that rear sway bars (anti-roll bars) became standard from the factory on early model 260Z's. There were various after-market kits available to add rear bars to 240Z's (both front or rear oriented varieties) as early as 1975.

My '73 (Mfg date 1-73) had rear sway bar mounts, but no rear sway bar.

--John