Rear Strut housing replacement or not

[Homepup]

I'm in a weird situation. I ordered new rear struts for my 1973 240Z (which has been all original on everything I've touched so far) but noticed they don't fit exactly (diameter of the strut housing is larger and the strut nut that came with the new strut is too small). After comparing to a spare rear suspension I picked up, the struts fit on that one fine.

I'm guessing that someone must have swapped in a 280Z rear suspension at some point (there's number on the outside, Nissan 55303 N4600 AMPCO Japan) and the spare one I have on hand is the actual one for a 240Z.

I'm now debating, do I return the struts I just ordered and pickup some new 280Z struts that will fit (since I've already rebuilt the brakes and seem fairly certain that the rear bearings are ok) or swap out this one for the spare 240Z rear suspension (but I'm not sure of the condition of the rest of the parts in it and I'd have to change both sides obviously but only have the drivers side removed currently)?

Are there any downsides to leaving it as a 280Z rear suspension? I notice the strut housing is almost 2 inches higher along with being a larger diameter. I haven't looked to try and identify if the differential was also swapped but welcome hints on how to do so easily. Any issues if it was still a 240Z diff with the 280Z suspension? Would seem odd that someone might swap in a 280Z diff but leave it the original 4-speed transmission.

[Zed Head]

11 minutes ago, Homepup said:

I notice the strut housing is almost 2 inches higher along with being a larger diameter.

That does sound like the 280Z strut.  The strut towers in the body of the 280Z are taller than the 240Z's.  I've never heard of anyone doing that swap, seems like there would be very little suspension travel and the springs would be designed for more wight.  The back end would be higher.

If you look closer you might find more modifications.  Cut springs maybe.  The shocks might be fully compressed already.

I'd guess that you'd be better off resintalling the 240Z suspension.

Here's a link to the parts page.  Not much interchange.  p.s. you can tell an R200 from an R180 by the rectangular block of metal under the drain plug on the cover.

https://www.carpartsmanual.com/datsun/Z-1969-1978/axle/rear-suspension
 

Borrowed this from a recent BaT listing.

[Homepup]

Thanks for the reply. I agreed and went ahead and moved the new brake pieces I'd just put on the old 280Z suspension over to the new 240Z suspension. It was like doing 3 brake jobs at once by the time I removed the old brake parts too. Ugh.

So my differential does not have that little rectangular block below the drain plug. Does that mean it's an R180 (I'm guessing by what you described before)?

[dutchzcarguy]

4 hours ago, Homepup said:

little rectangular block

??

I see the difference bij looking at the rearside.. (Very easy to see by looking under the car from behind!) When you see cooling ribs it is a R200 the one without is a R180.  (Please correct me if i'm wrong..)

[Zed Head]

Cooling fins are on the CLSD R200's.  The open R200's just have the plain covers.

[Terrapin Z]

R200 is wider and more round. R180 is more rectangular. 

 

 

[dutchzcarguy]

17 hours ago, Zed Head said:

Cooling fins are on the CLSD R200's.  The open R200's just have the plain covers.

Then i have some news for you (guys..)  My 280zx is a original The Netherlands delivered (EURO) Car.. and it has a original to it R200 with cooling fins on the back!

I'm not sure about my other 2 280zx's i had but they had the same 200's under them as far i know..  (I could look at old pic's but i'm not bothered..)

[dutchzcarguy]

I was curious and took a look in my 280zx service manual.. and YES! The R200 has a special European rear cover!  It's has the ribs for extra AUTOBAHN cooling! 🙂 

[Zed Head]

That's pretty "cool"!   Can you take a picture of the page and post it?  I assume that it's in English?

[Zed Head]

@Mike

Edit - but now it has come back.  Strange stuff.  Probably uncipherable.

This thread has disappeared from the Activity page.  It should be one of the top ones since I posted three hours ago.  But I can get to it through the Notifications links.  Weird.

Here's the latest on the Activity page.  CO's five hour old post is top of the page.  

Edited September 6, 2024 by Zed Head

[dutchzcarguy]

Zed Head..  I just loaded my pics yesterday to my computer that where on my phone and i didn't make a pic of it so it's not on my pc or phone..

If you really really want a picture. you send me a pm with your mobile phonenumber i send you a whatsapp with as much pics you like of the service manual!

( It's a pic of the rear axle with everyhing on it and in the right lower corner it says near a little pic of the euro back cover: "european only"

[dutchzcarguy]

After i posted this, it's on the homepage the number one topic Zed!  (I don't know if it was in the top12 as i went to notifications first and posted the above answer

Oh.. btw almost all my service manuals are in english.. i got only one about the injection system from a 280zx in Dutch!