Swapping the diff mount.
 

Pictures . . .

I had an annoying time finding a quick resource on the best way to accomplish this on the ZX, and neither the Haynes or the factory service address it. I found some accounts saying how it was best to drop the fuel tank for clearance, others saying to drain the fluid so you can remove the diff cover. And as per usual, most of the advice having subtle differences pertaining only to the S30.

Thankfully, none of that is necessary. I took some pics of the process today. Not enough to be a super detailed DIY, but plenty to get people pointed in the right direction.

After taking off the 2 10mm screws that hold the gas tank guard flap in place, you can get access to the 3 big nuts on the mount itself, they're all 22mm. The bottom bolt can be pretty tough, so use a deep socket, 1/2" drive, and a decent breaker bar.
https://dl.dropbox.com/u/25396429/pi...iffmount01.JPG

Don't take them off just yet, just loosen them. Lifting the bottom of the pumpkin slightly with a jack might make it easier, as it'll take the weight off the nut on the long through-bolt. It'll also hold things steady while you take off the next bolts . . .

Next up, undo the 4 long through bolts that attach the diff to the rear crossmember. They're all 17mm, and it'll take a little creative wrenching to hold the top nut in place while you break the lower ones free. Again, go 1/2" drive on them, they should be pretty tough to crack.

With the differential still supported by a jack, take off the three 22mm nuts on the diff mount. Lower the jack slowly, and it'll rock downwards. Some wiggling & angling towards the front of the car, and you'll have enough clearance to pull the mount off and put on the new one:
https://dl.dropbox.com/u/25396429/pi...iffmount04.JPG

Don't tighten the 2 nuts on the new mount all the way yet, leaving a little wiggle room helps when lining it back up. Jack up the diff slowly while pushing forward by hand, and get that stud through the new mount - it may take a few tries. Once it's through, thread the bottom nut on partially.

Play with the jack to find the best height to reinstall the 4 long through-bolts . . . and torque everything down to the settings in the service manual, obviously.

https://dl.dropbox.com/u/25396429/pi...iffmount05.JPG

Hope this is helpful to someone someday . . . :shrug:

Thank you so much. I just picked up a 76 280z and I need to do this. :icon_super:

Welcome to ZDriver! :006:

Just an FYI, this is for a 280zx. The 280z setup is different. :D Download the FSM from www.xenons30.com/reference

I just removed mine. Loosened everything as described but my pumpkin would not tilt back for the life of me. What am I doing wrong.

Eventually pulled the rear diff cover and with a lot of effort managed to wiggle it out. I have no idea how I am gonna be able to reinstall everything.

Was your props haft perhaps removed for this? Something is holding my diff parallel. I did remove those 4 long bolts on the diff yes.

Only thing I can see different is that my car is jacked up and yours is on the ground. Lowering my car to the ground however didn't help though.

Ok had another look this morning. The orientation of the u-joint on the props haft makes a difference. Turning it the right way will allow the diff nose to tilt up as above. If it's the wrong direction forget it.