Restoring a 1968 Datsun 510 Sedan – Part 4

Aaaaaand, we’re back!

Y’know, I’ve always said – I could get a lot of work done if I didn’t have to work.

So, with the work on the individual components of the rear subframe completed, and everything reassembled, it was time to mate the entire subframe back to the car. This looks daunting, because it’s an awkward (and heavy!) assembly. However, if you use a 2×4, you can do it yourself, if you balance the whole thing on a jack and a pair of jackstands. Just lift it one notch at a time, until the rear differential mount bushings AND the subframe mount bushings are aligned with their respective bolt pins. Don’t forget to add some lubricant to the INSIDE of the bushings, to eliminate any chance of squeaking later on. Once the assembly is high enough that the bolt pins start peeking through the bushings, you can reinstall your bushing caps (large washers) and snug it up the rest of the way with a ratchet or air wrench (don’t forget to use anti-seize!).

NOTE: If you’re a real 510 pro, you may have caught my faux pas in the last installment. When assembling the differential to the crossmember, insert the long bolts through the diff and crossmember from the bottom, with the nuts on top. This way, you can easily drop the differential later without removing the entire crossmember assembly. I goofed, and inserted them from the top – but I don’t plan on pulling it all apart anytime soon!

Here’s the rear crossmember assembly bolted up in place:

Next up, the brakes. All of the brake hardware had already been through the tumbler and polisher, and the backing plates were painted. Now, it’s time to fit the upgrades. Since the drum brakes were going to be retained, we’re going to want everything to work perfectly. No sense spending all this time cleaning things if they’re not going to function exactly as they did when brand new. So, I replaced the rear wheel cylinders for good measure. These can be rebuilt, but the price of a rebuild kit and the time spent just doesn’t justify messing with them. The adjusters can be refurbished, however. It’s a simple matter of removing the assembly, unthreading the adjustment shaft, removing the two wedge-shaped pistons, and cleaning everything in solvent. Once they’re spotless, use some good high-temp brake grease (I use the red Hawk grease) on both pistons and the shaft. Assemble it with the adjuster completely retracted, and reinstall on the backing plate. The spring clips can then be reinstalled on the backing plate. Then, I placed a dab of grease on the contact points where the edges of the brake shoes would touch the backing plate. Installing the brake shoes is tricky, but once you’ve done it a few times, it’s simple. A helper, and a couple pair of strong needle-nosed pliers comes in handy here. Here’s a look at all those components as they came together:

Datsun 510 owners have always had problems finding the perfect rear spring setup for their cars. Because the 510 uses a rear coil with a small outside diameter, very few springs will work for this application. Cutting springs is for chumps, and there’s not a lot of aftermarket options. However, the 510 seems to sit *just* right in the rear by using a set of Roadster Sport Comp FRONT springs. They fit nicely into the spring pocket, lower the rear perfectly, and have sufficient spring rate to prevent bottoming out (and they match up nicely with the Megan coilovers already installed up front). A set of fresh axles were leftover from the 240Z build (it pays to hang onto extra parts if you’re building more than one Datsun), so those were bolted in place. A set of new KYB GR-2 rear shocks and the rear suspension is good to go.

Finally, a pair of finned aluminum drums from an early Z would provide a little more cooling, as well as some weight reduction. A half-hour date with the bead blaster, some high-temp clear coat, and they turned out good as new.

Here’s a few pics of everything in the rear suspension buttoned up and ready to roll:

I hope everyone had fun watching this phase of the build. In the next episode, we’ll test-fit the wheels and tires, get the wiring harness taken care of, and maybe even get the engine and trans ready to install!

Click here to read Part 5 of the Datsun 510 build!