Mustache Bars and Rear Diffs Advice

[Clay C]

I have an early 71' and am running into the problem with the diff front mount/insulator where the only one I can source is from '72 onward which pushes my diff backwards. I've heard you can rotate the mount 180 and it will bring it forward. I have also installed the RT Diff bracket with the red Bush on top pressing down on the diff to avoid going back with the strap. Well since my diff has moved backwards (i think) because of the newer front insulator the RT mount is falling right on the yoke which is no good. I haven't tried to rotate the mount yet and reinstall.....The car is at my friend/mechanic/body guys shop but after taking it in and out about 4 times yesterday I gave up to do more research. 

I have both style's of mustache bars...I have both styles of rear transverse link mounts....I also have a very good functioning r200 sitting in my dining room. Z Store Website says I can use the newer mount with the 72 mustache bar and trans/link mount but I still don't see how that helps unless i flip the front insulator over which may be fine, it doesn't appear that it should matter other than it may make my drive shaft too long or maybe now its too short....Haven't got that far, no transmission in the car. Would you all go with the changing of the mustache bar and rear transverse mount? Or maybe the R200 would fit perfect? If anyone knows anything about this I could sure use some advice to avoid another 4 installs of the rear diff! I was trying to keep this car as close to original as possible but seeing as how I cut the front clip off a 260 and replaced mine that dream is out the window! I didn't realize they were noticeably different. This is my first rodeo.

Maybe there is another solution all together?

[Zed Head]

You're going to have a problem with propeller shaft length.  It will be too short if you move the diff back.

 You should have all of the parts you need except the propeller shaft, to get the diff installed correctly, with the RT mount and rubber snubber and 72 Nissan mount.  It sounds like you're installing something incorrectly.  Almost like you're installing the RT mount backward.  The RT mount should not interfere with the propeller shaft yoke at all.  Not clear how that can happen.

" the RT mount is falling right on the yoke"

There are pictures on the site.  I'll post a link if I find some.

[Zed Head]

I wonder if the strap mounting holes on the early 240Z's are moved forward.  That would explain why the RT mount would be moved forward too, sitting over the yoke.  I don't think I've seen where someone with the forward mounted diff used an RT mount.

[Clay C]

Maybe I scrap the RT mount. It’s not on the prop shaft yoke it’s dead center on the diff yoke/u joint...actually rubbing right on top of the metal dust cover that’s welded on to keep stuff out of seal area. The mount is in there correctly far as I can tell because the gap for fuel lines is on the right side of the car. I can modify the mount without a ton of trouble. 
 

I think I read somewhere in a previous post the half shafts should be completely perpendicular to the wheels. If I can get that lined up I’ll deal with prop shaft later. 
 

thanks. 
 

[heyitsrama]

clay take a look at this: 
 

http://ace240z.com/rt%20mount.html

Edited July 30, 2020 by heyitsrama

[Zed Head]

That's a good find.  I think the reason is not quite right but the fix looks right.  Who is that guy?  I inserted your link so that it clicks through.

http://ace240z.com/rt mount.html

Not really correct - 

"As it turns out, the transmissions for a '70 and '71 240z were mounted slightly back than with subsequent years. "

Edited July 30, 2020 by Zed Head

[heyitsrama]

1 minute ago, Zed Head said:

That's a good find.  I think the reason is not quite right but the fix looks right.  Who is that guy?  I inserted your link so that it clicks through.

http://ace240z.com/rt mount.html

Not really correct - 

"As it turns out, the transmissions for a '70 and '71 240z were mounted slightly back than with subsequent years. "

Hes some dude with a Z, http://ace240z.com/who.html

I wonder if hes on this forum, i dont see anyone under Ace.

He seems to be doing a lot of work on his car http://ace240z.com/current.html .

[Zed Head]

Looks like he's a zcar.com guy.  Zcar was barely alive a few years ago, haven't been there much lately.

"The various members of Zcar.com contributed valuable guidance."

[heyitsrama]

1 minute ago, Zed Head said:

Looks like he's a zcar.com guy.  Zcar was barely alive a few years ago, haven't been there much lately.

"The various members of Zcar.com contributed valuable guidance."

I sent him an email and linked him to this thread, maybe he will join.

I actually don't have much insight to this as i have later generation cars, I just wanted to drop the link.

 

[Clay C]

That’s very helpful and thanks a ton.  I feel like I’m taking crazy pills sometimes with this car. I don’t know the differences in the year models but this isn’t the 1st problem with the early 71 I’ve ran into. I don’t have the parking brake cable in yet so that would have been something else that made me throw a wrench through a window. 

[Zed Head]

I took a closer look at his solution and I think that there are other ways to get it done.  But it's good to know what the problem is.

[heyitsrama]

I think you'll run into different style transmission mounts, based from what @Zed Head observed on Ace's website a different transmission position and from  https://technotoytuning.com/nissan/240z/z-type-3-transmission-crossmember-l-series

 

And possibly different sized outer tie rods, but thats for another thread....

Theres another picture on Ace's website that shows the underside.

@Clay C did you happen to get the mustache bar from the 260z?

Edited July 30, 2020 by heyitsrama