Help Installing Differential

[Armand]

Hey guys,

 

I currently have a 1971 240z with an R180 differential. I had some pretty bad clunking coming from my rear end during shifts. So I removed the diff and found the stock front diff mount was a bit torn. So I ordered a billet front one from ArizonaZCar. I removed the stock one, installing the billet one with the offset screw toward the front of the car. Jacked up the rear diff and the front diff mount was completely mis-aligned with the crossmember.

 

Ok, I just have to move the diff around right? After setting the diff down and jacking it back up(did this about 5 times) and I still had no luck. The diff simply sat too far forward, and it can't align with the crossmember. So I was thinking my memory might be wrong so I removed the diff mount and flipped it so the offset screw is toward the rear. At the time this seemed to be more logical. So I pushed the diff as forward as I can and had my brother jack up the diff. This time the diff seemed to be in a much more logical position. But it was still off by about half an inch, much closer than before.

 

SO I called up Arizona Z Car and they told me that the offset screw is supposed to be toward the front of the car. OK, so I flipped it again, and tried getting the diff aligned about three more times. Still had no luck, the diff mount just sat too far forward. I made sure the top straps were not interferring with the diff alignment, and I studied all the books I had and had no luck. I'm very pissed, and have spent close to ten hours trying the re-install the diff.

 

Can someone guide me to what I might be doing wrong? For those who have installed this diff mount, did it go smoothly or did you have to do something specific to get it to fit? I'm very clueless now and I'm beginning to think something might be bent. When I was originally removing the diff, I forgot to put a jack under the diff when I removed the front crossmember, and the diff swung down a bit and hit back of the diff hit the rear (don't know what you call it, I think dog legs?) thing that the back of the control arm attaches to. It wasn't a hard hit at all but would it cause something to go out of whack? Everything seems straight to the naked eye.

 

Any help would be greatly appreciated. Thank you in advance.

 

-Armand

[MrFancypants]

Make sure your mustache bar is installed the right way around. Dont ask how I know

 

 

 

 

- Greg -

[Pop N Wood]

Three things. First 71 240's had the diff mounted 35 mm farther forward than later variants. So unless someone has upgraded your car to move the diff back where it belongs, you will have to turn the diff mount backwards from the way everyone else uses it.

 

Second, I think the diff mount for the 71's is slightly different from the later models anyway. At least if I remember correctly MSA has different part numbers for the early vs. later cars.

 

Third, don't use a solid front diff mount. Not unless you also plan to solid mount the rear of the diff.

 

http://forums.hybridz.org/showthread.php?t=108276&highlight=solid+diff

 

http://forums.hybridz.org/showthread.php?t=117336&highlight=solid+diff

[Armand]

Cool thanks! I'm pretty sure I'm just going to get a stock OEM piece and return the solid front diff mount.

[Ejkej]

Hi!

I've got the same problem - with regular front mount on my '76 280Z.

I can't install the differential in it's place on a crossmember. After attaching it to the mustache bar I can't push it enough towards the rear...

 

I have the mustache bar installed as shown in the manual - that way it leaves less place for the diff.

 

Any help?

Edited June 14, 2011 by Ejkej

[Ejkej]

OK, I think I have found the answer - the mustache bars on 280Z and 240Z seem to be installed in different(oposite) direction... at least that's what I saw on some pictures showing Z's rear suspension.