Zed Head

That is foil-backed Mylar. There's also a clear Mylar that has no EMF protectant properties. Used to make transparences. Mylar is a trade name for the base material. It's polyester. https://usa.dupontteijinfilms.com/resources/trademark/

What would they make? If the 240Z shafts don't fit then he can't just say "make me a 280Z propeller shaft". He said he had a stack of 240Z shafts that have small flanges, whatever that means. If they don't fit then a 280Z shaft won't fit either. The reason the drive shaft shops won't replace the u-joints is probably for liability reasons. Nissan says that they are not repairable.

Here is more about the oddball 1975 flange. I'm not so sure this guy's thoughts about the ZX diffs are correct, I've never heard of anyone finding a 280ZX diff without the typical DAT-110 pattern. The 300ZX diffs are definitely different though. But, he does have dimensions shown, and 1975 ID'ed as the center flange. I have had a square flange and a round flange on two diffs from 1976 and 1978 that had the same DAT-110 bolt pattern. So you can't go by shape of the flange. You have to take the measurements. https://jagsthatrun.com/collections/datsun-z-parts/products/adaptor-flange-for-datsun-z-v8

Good luck man. You seem to enjoy claiming that people are wrong even when surrounded by evidence that they are right. Hard to understand. I have had four separate propeller shafts in my possession, two short ones from early 240Z's, a 1976 280Z 4 speed, and a 1978 280Z 5 speed, and five differentials, all R200s, and several transmissions, three 5 speeds (1978, 1981, 1983) and a 4 speed (1976). I always try my spare parts out for fit and function and all of the propeller shafts fit the diffs and the transmissions exactly the same. They were all swappable. The flange was shaped differently on some of the diffs, and the 240Z yokes were smaller in form, but the bolt pattern and bolt sizes were the same. Even the nuts and bolts are the same. The 75 280Z diff flange is unique. Not sure why. If I had to make a WAG (and I do since you don't post pictures or measurements or any details of your claims) and guess why you're having so much trouble, I'd say that you have a 1975 differential. But that's just a guess.

The internet says it is unrectified. How will you rectify that problem? https://www.autoelectrics.net/alternator_terminal_identification.html

The P terminal would be interesting. I don't really know how it works, I've seen it called a revolution counter or tachometer. Solution #4 works just fine for a 76 though.

The R180 and R200 size and patterns are the same. This was all covered in your other thread. The very early 240Z's had a shorter propeller shaft. And the 2+2's have a longer propeller shaft. But the front end and rear end of the propeller shafts fit the same way from 1971 to 1978 for Z car coupes. Except for the 1975 year. 1975 is an oddball year. Not really clear why you're having a unique problem. Are you trying to save money or just can't find something that fits? Are your u-joints even bad? They're pretty durable and don't often need replacing. Yes, Z Car Depot's ad copy is misleading. I would not trust it. I posted the link so you could see a source for parts.

It also comes on if the brake system pressure differential switch is actuated. I thought that the word "check" referred to the fact that it went on as soon as the key was turned on, confirming that it worked. "Checking" the light, not the system itself. Otherwise they could have just had the pressure differential switch complete the warning light circuit, and the light would never light unless there was a problem. You'd never know if the light worked or not. I did find that it was a convenient warning that your engine had died though. I ran a tap line over to my fuel pump power line next to the seat to power the relay. Which is controlled by the AFM contacts and fuel pump relay on a 76. My original comment was more about the fact that even with somebody else's instructions you still have to make sure it will work for your particular situation.

https://zcardepot.com/search?q=propeller+shaft&type=best-selling

Here's a good reference chart. If you don't look at the actual mating surface on the inside of the yoke you can be fooled by the taper of the rough casting on the outside. https://www.dennysdriveshaft.com/c974_u_joints_by_size.html

Here are a couple of videos I found from a guy who does some good professional electrical diagnostic work on his channel. On the mechanicals though, he seems not so capable. He goes through all of the basics though.

A picture would be good here...

Not really clear what you're talking about when you say lock or lock point. Sounds like you're saying that the snap ring grooves of the u-joint don't match the inner surface of the yoke. so the u-joint is not centered properly. It would help your argument a lot if you had a picture of you taking a measurement. Not clear where you're getting your information from. John from Lugoff probably would have noticed a 1/10th of an inch gap on each side (huge), but maybe not. http://www.northerndrivetrain.com/product/NEA-1-0430.html

Thanks for doing this. Searchability by word would be great. I have not downloaded it but most of what is available out there is either just the full FSM as one giant file or a collection of chapters with bookmarks. Are you using some sort of character recognition to convert pdf images to actual searchable text files?

https://www.classiczcars.com/forums/topic/65183-78-22-driveshaft-u-joints/

It's not the alternator it's the wiring from the external VR in 1976. If you follow the two main wiring suggestions on the internet, one disables the brake check light, the other causes the relay to be on al the time, draining the battery. The wiring diagrams don't work for 1976. The Frontier alternator is just like a ZX alternator except for the type of electrical connections.

I think we owe kudos to Z Car Depot for showing that the Frontier alternator fits, has the proper pulley, and has higher amperage. Too bad the instructions he provided are so poor, he opened the door to your discovery. The wiring is pretty straightforward, once the Sense and Lamp wires are understood. More complicated for the 260Z of course, with the fuel pump wire. And the 76 280Z has the brake check warning lamp to worry about. Most people go for more amps because of low amps at idle RPM, causing dim lights and slow wipers. Do you have an idea of if the Frontier unit provided higher idle amps with wipers, lights, heater, etc. on? Driving through a storm on a cold night.

Try opening up the idle speed screw and see how it starts. It's the one with the big washer head and spring underneath on the throttle body. If it starts and runs correctly right away but the idle is too high after it warms up then that would be an AAR problem. You've talked about how far open the AAR is but you haven't said that it closes quickly like it should, from the electrical heater inside. It might be that the AAR does not have electrical power and that you've adjusted the idle speed for a warm engine.

Good luck.

I had one break with the hard PU on the back and realized that the bushing on the back restricts the motion of the tip of the rod as the rod itself moves up and down with the control arm. This puts a big load on the stress riser at the bottom of the threads and causes the metal to fatigue and break. The rubber bushing is actually formed so that it allows a wide range of motion, up and down and sideways, of the rod but still controls fore and aft motion.

Not clear what this means but if the tachometer needle does not seem to match engine RPM correctly that is a sign of an ignition module problem. If banging on the ECU clears up the rough running, that's an ECU problem.

Kind of sounds like the bad ECU problem, or bad ignition module. Did it smell like raw fuel?

Same thing?

Need details. Without the AAR you would need to hold the throttle pedal down with your foot to keep RPM up.

1978 had the first "adaptive dwell" system for the Z's, I think. At least they trusted it enough to run enough current to open the plug gaps. The 1978 spec should work for the Ignitor II. Some people like to run the projected tip plugs but I'm not sure it makes a difference. Not sure why Nissan changed, maybe due to detonation issues with the leaner EFI systems. Just a guess.