1973 Rebuild

[Matthew Abate]

Alright, the suspect carrier is in a vat of oil and the new one is in. This one has fewer miles on it anyway, so I’m looking at this as a glass half full situation.

Once I had everything ready to go back in I put fresh bearings on the new carrier and new seals in the case, which is what caused this most recent delay. 🙄

Figuring out how to torque the ring gear bolts without putting it in a vice was fun. The key ended up being an oil filter wrench with a reinforced rubber strap. Two people can do it, three would be better. They need 78 foot pounds on the Subaru diff (probably the same on all “K” r180s). They are only 50 to 58 on the Datsun (probably because they have lock washers).

Luckily I had the right mix of shims to get the backlash within tolerances (0.1mm to 0.2mm).

Major obstacle out of the way!

Edit: I forgot to mention the Ron Tyler style differential arrestor. Not much to say about it other than I was surprised how much of the bushing had to be removed to get the r180 to fit. I only had two notches to go before it was all the way to the hilt. I’ve seen these where there was a gap leftover but they must be using a different bushing. This one is pretty compressed. This isn’t going anywhere.

***

So now the differential is in. My 240z now has a limited slip… sort of. It’s a Torsen, so not a true LSD, but I’m thinking this is the most drivable option given it behaves like an LSD under power and like an open when you let off (open into the turn and closed out of the turn). 

***

This was perhaps unnecessary, but Nissan added this transmission mount shield when they designed the 280ZX/S130, so it is probably not a bad idea. It’s not like it weighs a ton.

[grannyknot]

I've never seen that transmission mount shield before, nice addition.

[Patcon]

I wonder what it's shielding from?

[Matthew Abate]

Couple of updates..

Other than the half shaft, the drive train is complete.

Restoring the driveshaft was simple. I had read somewhere that the u-joints are NLA, but I found them in two seconds at Z Car Depot, so I don’t know what that’s about.

 

***

I swapped the flange from my Datsun diff and put it on the Subaru way back, so it went right in.

Hanging the rest of the Spirit Garage exhaust system really felt like reaching a summit. Maybe it’s because now everything I need to do start the car is in the engine bay, which feels more doable conceptually.

The system went in really easily except for a few minor things:

The hanger tab in front of the muffler is about an inch too far forward, so I had to put a bolster on the bolt to take up the slack. I don’t love how it looks so I plan to get two that are half as long. That should clean it up a little.

The pipes hang a little low at the differential crossmember. I had expected them to tuck tight up into the relief on either side of the, but if I lift it any higher it hits the differential. That’s a little bit of a bummer, but it’s similar to what I’ve seen on some others.

Also, the exhaust tips are a little close to the rear valance. I could get different hangers, but I think it will be okay. Still plenty of time to think about that.

For hangers I opted for some universal pieces from Walker Emissions (36273 and 36274) that I just cut to an appropriate length.

So now I just need some stainless clamps and some acorn nuts to protect them from random debris.

Now back to the engine bay.

Edited January 7 by Matthew Abate

[Matthew Abate]

I took a break from the car to do some self care and get my mind in order by getting my tools in order. I bought myself a few packs of Toolbox Widget organizers, and so far they are doing the job. The box doesn’t hold quite as much now, but I also don’t have wrenches and sockets sliding around all over the place and piled up on top of each other.

Putting a layer of anti-slip foam on the bottom first really helps it feel slick. Not sure how I’m going to keep the dust out, though.

…

So you may remember that I was having a hard time adapting the 240z coolant routing to having Mikuni triples because that eliminates the carburetor warming channel that connects the bypass tube to the thermostat housing. I had experimented with just running a stainless steel tube in place of that system, but it fouled the manifold and front carburetor.

After much back and forth with various thermostat housings I found that the early ZX housing is the one I wanted. It has many extra ports, but these can be plugged with various fittings. The hardest one to find is the 1/4” BSPT, but McMastercarr had them.

Next I tried a few different Nissan fittings that are 1/4” BSPT male to a 3/8” hose barb. I found the 105° angled one to work best for clearing the distributor.

Then I found a 280zx bypass tube, which more or less mounts right up, but because it is meant for the fuel injection system I had to remove approx. 9” from the side that wraps around the thermostat and put a new bead at the point where I cut it. It also needed some spacers to change the geometry and allow it to clear the temperature sensor and point the tube at the 3/8” fitting mentioned above.

After that I needed a ZX water inlet with the 3/8” tube coming off the threaded adapter that connects to everything already discussed. That has a 5/8” tube pointing back to the heater hoses, so I had to replace all of my 3/4” hose. It also meant going full ZX with all of the fittings and getting rid of the 240z y-pipe. I had to find a coolant regulator/check valve, which is nearly a unicorn part. I know seller with some that are NOS in the box, and normally I wouldn’t go with used parts on a fresh engine build, but I’m not paying $175 plus shipping for something I can get for $30 in good used condition and is essentially just a 3/8” tee with a check valve.

The coolant system is now closed. After much trial and error and purchasing too much hose, I have the whole system plumbed and clamped.

I only used one of the OEM 240z hoses, and I cut it down significantly. They wouldn’t have worked at all with the Vintage Air system I have, so I put a pair of their bulkhead barb to threaded fittings coupled to their 90° barb fittings. I bought a pair of Continental hoses with a bunch of turns from Summit Racing, which allowed me to keep everything under the dash pretty snug. I was worried I would need to make a bracket for the heater control valve, but it’s floating pretty far from everything so it should touch anything even with a huge amount of vibration.

So now I just need to check all my fasteners and get a radiator overflow tank. Next is decide whether to move on to the fuel system or put the AC lines in.

Edited February 4 by Matthew Abate