A classic S30 Z car deserves a well-planned rear end setup. The upgrades will transform how your car handles and performs. The stock parts were quite basic back in the day. But modern parts can transform how your Z works and puts power down to the ground.
You have several practical options to beef up that rear end setup. Some stronger axles will keep all of the parts reliable when you're pushing it hard. A limited-slip diff transforms your cornering ability - you'll feel way more confident taking those tight turns at speed. Let's talk about the suspension parts - upgrading those bushings and mounts will tighten everything up nicely.
When you add beefier axles and that limited-slip diff, your Z hooks up like it's on rails. Your classic Z rewards you with better launches and more predictable handling, plus that satisfying planted feeling through the corners.
Let's get started!
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Table of Contents
Popular Rearend Upgrade Options
When upgrading your S30 Z car's drivetrain, it doesn't have to be stressful. You have a few solid options that'll match your performance goals and your driving style!
You'll love what a limited-slip differential can do for your car. These parts from businesses like OS Giken, Nismo and Kaaz will enhance your traction and handling. This makes total sense as your first serious upgrade! The second you step on the gas, you can see less wheelspin and better control - especially if you're hitting the track or doing some competitive driving.
Strong axles are a big part of pumping more power through your drivetrain. Businesses like Driveshaft Shop (DSS) make tough axles that'll manage whatever you throw at them. You don't want your axles snapping when you're pushing your Z car hard. These'll make sure that doesn't happen.
When you're ready to go all-out, the aftermarket housings are the way to go. The Ford 9-inch rear end is tough and you can find tons of parts for it. Or you might want to check out a Jaguar IRS conversion. It'll make your car handle like a dream. It has an innovative design. Just remember these aren't cheap upgrades and you'll need some serious mechanical knowledge to get them installed.
Let's break down what you get with each option. A limited-slip diff will instantly improve how your car drives but won't make anything stronger. Beefed-up axles are perfect when you're making big power and keeping everything in one piece. Those aftermarket housings are the complete package. They deliver stronger, better handling and improved cooling all wrapped into one.
Modern CV axle conversions perform effectively with your stock R180 or R200 diff and they're quite easy to install on a Datsun Z. The catch? That outer stub axle is still going to be your weak point. Some people swap in an R200 differential when they want more power. But you'll need deep pockets and steady hands for that job. Going with a Ford 8.8 rear end means lots of cutting and welding. But you'll end up with something reliable.
FutoFab makes some strong axles and stub axles that'll work with your stock diff or even an STI differential. These are perfect when you want bulletproof reliability without completely redesigning your rear end.
Limited-Slip Differential Benefits
An LSD can change your S30 Z's performance right from the second when you hit the gas. You'll feel the real change as the power flows evenly to all wheels - stopping that annoying one-wheel spin when you launch hard or push through corners. Your car will stick to the road much better and it can give you extra confidence to lean into those turns.
You'll love how your Z now works with an LSD installed. The extra grip means you can control your car better through tight corners - you won't have to fight with understeer or oversteer as much. Want to get a bit frisky with the throttle mid-corner? Go ahead - your car will respond more predictably and stay planted exactly where you want it.
The weather won't slow you down as much either. Your Z will hook up better on dry pavement and it lets you launch harder and corner faster without spinning a wheel. When the roads get slick with rain or snow, your car stays more stable and in control. Think of it as upgrading your Z to manage whatever Mother Nature throws at you.
Every turn can become more exciting with an LSD. If you pick a clutch-type, Torsen or viscous diff then you'll see how your car feels more planted and stable. No more fighting the steering wheel over bumpy roads or dealing with that unsettling wobble in slick conditions. Your connection to the road gets tighter and that makes every drive more engaging.
Performance enthusiasts praise LSDs because they're a big part of upgrading the S30 Z. Track day warriors and spirited drivers especially like how these diffs enhance their cars' capabilities. Your tires will thank you - an LSD spreads the wear more evenly between the wheels. The money saved on rubber is a nice bonus. You can drive with more confidence when you discover how your Z can manage whatever driving style you throw at it.
Aftermarket Axle Strengthening
You'll find lots of solid ways to beef up your axles and make your ride more reliable! Let's take a look at some practical options you can pick from right now.
Start with some aftermarket axle shafts - they add plenty of strength to your vehicle! You might want to check out the Chromoly Performance Axles. These tough parts pack more punch than the factory-installed ones (these tough parts come with extra splines to spread out the stress better). Drivers swear by the Longfield axles from Trail-Gear because they're built like tanks.
When you put in those stronger axles, you won't have to worry about them bending or snapping during intense driving or off-road adventures. That security makes all your rides more fun!
Maybe you need something that fits just right? Take a look at the cut-to-fit axles from vendors like West Coast Differentials or Currie Enterprises. You'll get exactly what you need for your setup - everything will line up well.
When you start improving your differential parts too, grab some heavy-duty hardware from Moser Engineering. You'll notice the difference when you're pushing your vehicle hard. Need a complete package? Dutchman Axles will set you up with everything from basic shafts to full kits with all of the parts you'll want.
For your S30 Z Car, switching to CV axles might be perfect. You'll need some adapters to make them work with your latest differential. But they'll fit right in with your R180 or R200. Just remember that your outer stub axle might need some work.
FutoFab makes some tough axles and stubs out of hardened steel. Their six-bolt setup can give you some more muscle than the factory parts. But heads up - you'll need to follow installation procedures and they won't work with standard replacement axles.
Installation Process Guide
You'll need a few basic tools and parts before starting your differential swap project. Make sure you have your new differential ready - something like a 3.9 LSD can work perfectly for most setups! Grab your seals and hardware too and remember to check those U-joints you have on the driveshaft.
Getting that old differential out is your first big step. You can take off those upper rear differential mount nuts and use your jack to push the differential forward. Once the rear studs can clear their holes, you can lower the whole assembly down and out of there.
When you're putting in the new differential, start with any new mounts you have picked up - Ron Tyler mounts are quite popular with many people recently. Line everything up and lift that new diff into place. Make sure you have those front bolts and nuts nice and protected before sliding those upper rear mounting studs home. Pop on your nuts and washers (but hold off on the final torque) until you have everything lined up well.
Now comes the hard part - hooking up your driveshaft and halfshafts. You'll want to be extra careful sliding that driveshaft input yoke onto your transmission output shaft. One wrong move and you'll damage that rear seal. Hook up your driveshaft to the differential's front flange and remember to spin the driveshaft as you torque those bolts down. When you're putting in the halfshafts, watch those fasteners on the output shafts - and use locking split washers.
When you install of the remaining parts, the front differential carrier needs to go back in and you'll want to grease up those bushings on your rear lower A arms before you start torquing everything down. When running a new suspension kit, just follow along with those instructions for assembling your rear control arms, knuckles and axles.
Here's what might confuse you: those ears on the differential could be different lengths! You might run into circlips instead of center bolts. You also have to make sure you're using the correct oil fill plug. Keep your work area clean, use lots of grease and double-check all your torque specs.
You'll want this gear: jack and stands, sockets, a ratchet wrench, torque wrench, grease and lube, a paint pen for marking items, brake cleaner and safety wire for those CV joints.
Look - this is a starter project you can begin with yourself. But don't feel bad about calling in an expert. They have the equipment and know the techniques to make sure everything's installed with proper protection.
Cost vs. Performance Analysis
You can start balancing cost and performance by learning about your options for rear-end upgrades! You'll find several reliable options that can actually improve your car's performance without emptying your wallet.
Your stock rear end can work well with some basic upgrades. This is especially true when you're not pushing crazy power numbers. Think about some CV axle conversions and stronger control arms - they'll fix those tricky weak places around the outer stub axle. For budgeting purposes, you're looking at spending somewhere between $500 and $1,500. That can give you some some solid performance gains out of your ride.
If you're stepping up your game, an aftermarket differential swap could be just what you need. Businesses like FutoFab and Apex Engineered make some tough parts that'll change how your car works. Sure - you'll shell out between $2,000 and $5,000. But you can feel the change when you hit the gas!
You could also grab a beefier differential from a Subaru STI - this upgrade will boost your traction and handling stability. For pricing purposes, you're looking at $2,000 to $4,000. It works great when you want something harder than stock but don't need the full-blown aftermarket setup.
Want the absolute toughest setup possible? A Ford 9" rear end could be just your answer. Yes, it's the priciest path you can take. But nothing else comes close to handling massive power. You'll want this setup if you're building something and don't mind spending the extra cash.
For your money's worth, the CV axle conversion and better control arms pack quite a punch. These upgrades give you serious performance without breaking the bank. And when you need something beefier, that aftermarket differential swap really shines.
Just remember that shop labor and extras like new brakes will bump up your total cost (these aren't exactly quick driveway jobs)!
Build Your Dream Car
Your Z car's rear end upgrade path can come down to what you want from your driving experience. You'll feel a giant improvement in performance when you match the right setup to your driving style! Get clear about what drives you the most. Maybe you want more torque for acceleration, better handling in the corners or a reliable setup that won't leave you stranded.
Money talks when you're picking upgrades for your S30. You might drool over that fancy limited-slip diff - but your wallet needs to agree with your wishlist. Take a step back and look at the whole picture. Some mods will drag other upgrades along with them and the costs add up quickly. You can get exceptional results when you focus on the features that match your driving style.
Skillard knows what Z car enthusiasts like you're looking for. You want parts made just for your Datsun - not generic parts that sort of fit. That's why we pour our expertise into making better parts like our aluminum door cards, custom bumpers, center consoles and aero pieces! Every part we make is built to improve your car's appearance and performance.
Jump over to Skillard.com when you're ready to take your Datsun project to the next level. Our complete catalog has the parts you need to build your dream car. You'll find expert input on picking the perfect rear end setup, plus recommendations based on decades of Z car experience.
Think about how you drive, what you can invest and where you want your car's performance to be. Then grab the parts that'll help get you there!
