The axles on the ends of the CV shafts are the same as the short stub axles used with "u-joint" half shafts.  Here's a picture from 1983.  They call it a universal joint, some call it a CV, apparently it's not really a true "CV", yadayada...  They show the same diff with both types of axles.  It's the Rear Axle and Rear Suspension chapter.  So if the diff is the problem, you'll have the same issue with the short stubs.  Easy to test though.  You'd need to unweld that adapter also, or swap the hubs.

Bummer that you're having this problem.  Can't emphasize enough the need for taking good solid accurate measurements though.  No offense, but you still haven't measured the distance to the diff groove and compared it to the distance to the shaft groove.  Everything centers on those grooves and that circlip.  The concept is shown in the picture.  Numbers, numbers, numbers....

You might find that you can swap open R200 parts in to the CLSD diff.  Maybe you can just fix the diff.

If you have the time and patience it might be worthwhile to remove the open diff and set the two diffs side by side.  Then you can see the circlips and how they work and where they sit and pop some axles in and out of the open diff.  Maybe you'll have an "ah ha".

Thats what I am going to do. Look at the open diff, look at the clips in the open diff and compare. Maybe nissan gave more the wrong clips. Thanks for the pic. I'll let you know what I find. 

So I pulled the diff from the parts car and looked at it closely. It all makes sense and I can see the clip and groove. The lsd unit in the other diff does not have the clip groove at all. That lsd unit must be different. 

Weird.  I noticed that the grooves didn't seem obvious in your pictures.  But they didn't seem that obvious in mine either.

jmortensen knows a lot about diffs.  He might have some thing to share..

@jmortensen

It's dead obvious in the open diff. Let's hope someone can identify it. The case number on my open diff is the same as the lsd, but clearly the internals are different. I spun it to see if it had any markings, but nothing. It also does not look like the factory clsd from nissan. 

Interesting.  Maybe there's a diff that uses bolt-in axles like those for an R180 that will swap in to an R200 carrier.  Are those holes in the center piece threaded?  I asked that earlier when I thought it might be an R180.  If they're threaded, the threads would have had a purpose.

Edit - never mind, I see that that's just the end of the other axle.  Weird thing that you have there.

Edited July 4, 20177 yr by Zed Head

Yeah no threads like the r180. I really hope someone can help identify it. Sorry of pulling it from the case top look for a party number, I don't know what else to look for.

Here's my latest guess - somebody transplanted a CLSD from the front axle of a 4x4.  Looks like they had a variant of the R200 with a side tube to hold the axle.  No need for clips.

http://www.nissanpathfinders.net/forum/topic/40656-r200a-vs-r200awhats-the-diff/

I found it while searching for "R200 side gears", which came up with a bunch of stuff.  Maybe you can swap those side gears.  Worth searching.  Otherwise, I think you're kind of screwed.  It looks like one side of these might use a clip though, but who knows what other variations are out there.

You might take it to a local 4x4 shop.  Those guys break so much stuff that they know their diffs inside and out.

Here's the short axles.  No grooves in the splined section like ours.  Not really sure how they're held in unless they moved the clip grooves out off of the splines. to where you had put your clips.

 

You should just install that open diff, clip the CV axles in and run it for a while.  The LSD is nice but you won't really get the benefits unless you're up at 9/10ths, or driving in the wet, or dirt.  The IRS of the Z's really locks the individual tires down.  People report spinning two tires more often then not, with open diffs.

The CV axles were used on turbo and 2+2 280ZX's.  Generally thought to be stronger or at least more durable than u-joint half shafts.  Maybe smoother too.

Your only issue might be gearing, to match your transmission.